:ARY STATE PLANT BOARD April 1951 E _ 817 United States Department of Agriculture Bureau of Entomology and Plant Quarantine Agricultural Research Administration A DIGEST OF INFORMATION ON CHLORDANE By R. C. Roark Division of Insecticide Investigations % - 2 - GDHTEHT8 Page !>o. Chemical name 4 Common name 4 Lab el ing 4 Synthesis 5 Analysis 5 Physical and chemical properties Compat ibil ity Freight classification o. Patents o, Grades and specifications ^q Formulations of chlordane t q Effect on plants ^2 Effect on animals ^ Spray rosidu.es of chlordane 20 InBecticidal uses of chlordane , 21 Blplopoda Scorpionlda Orthoptera Acr ididae 21 Blattidae 25 Gryllidae 27 I soptera 28 Termitidae 28 Rhinotermitidae 29 Thysanoptera 29 Thripidae 29 Anoplura and Mallophaga 31 Anoplura - Haematopinidae 31 Anoplura - Pediculidae 31 Mallophaga - Menoponidae 32 Mallophaga - Philopteridae 32 Mallophaga - Tr ichodectidae 33 Homoptera 33 Aleyrodidae 33 Aphidae 3^ Cer copidae 36 Cicadellidae 37 Cicadidae Coccidae 38 Delphac idae 38 Psyllidae 3? Hemiptera 39 Coroidae 39 Lygaeidae 39 Mir idae 40 Pentatomidae 41 Tingidae 42 - 3 - Page No. Coleoptera 42 Car ab idae • 42 Chry somel idae 42 Coccinellidae 45 Cucujidae 45 Cur cnl ion idae 45 Dasytidae 49 Dermestidae 49 Elateridae 49 Meloidae 51 Scarabaeidae 52 Scolytidae 54 Tenebrionidae 54 Lepidoptera , ^ Aegeriidae 55 Crambidae ^ Lymantr iidae 56 Olethreut idae > 56 Phalaenidae 57 Pieridae 6l Psychidae 62 Phycitidae 62 Pyraustidae 62 Sphingidae 63 Tortricidae 63 Hymenoptera 64 Apidae 64 Cephidae 65 Formic idae 66 Tenthredinidae 69 Diptera 69 Agromy zidae 69 Calliphor idae 70 Cecidomyi idae 70 Culicidae 70 Hippoboscidae 74 Hypoder mat idae 75 Muse idae 75 Psychodidae 8l Sarcophagidae 32 Slmuliidae 82 Tabanidae 82 Trypetidae 83 Siphonaptera 83 Pulicidae 83 Acar ina 83 Ixodidae 83 Psor opt idae , 85 Demodicidae 85 Sarcoptidae 85 Tetranychidae 86 Trombiculidae 86 Trombidiidae 87 Literature cited 88 - k - The first announcement of the new insecticide now known as chlordane appeared in the December 19^-5 issue of the Journal of Economic Entomology. In an article by Kearns e_t al. ( 245 ) entitled "A New Chlorinated Hydro- carbon Insecticide" attention was called to a product having the empirical formula C^oH^Olg which had been found to be more toxic than DDT and to compare favorably in toxicity to the pure gamma isomer of benzene hexa- chloride to several species of insects. The compound, called 1068, was stated to be possibly a mixture of isomers. CHEMICAL NAME In the 19^7 subject index of Chemical Abstracts chlordane is called l,2,4,5,6 t 7,8,8-ectachloro-2,3,3a,^,7,7a-ttexahydro-4,7-methancindene. In certain publications the name l,2,4,5,6,7,8,3-octachloro-\7-methano- 3a,4 t 7,7a-tetrahydroindane has been used, [indan is 2,3-dihydroindene]. British patent No. 6l8,432 refers to the compound as octachlcrodicyclo- pentadianedihydride. COMMON NAME The selection of the name "chlordane" for this chemical was announced on February 25, 1947, following conferences of representatives of the Bureau of Entomology and Plant Quarantine, the Production and Marketing Administration, the Pood and Drug Administration, and the com- panies producing this insecticide. The name "technical chlordane" was proposed for the "commercially produced chemical containing 60 to 75 percent of chlordane, together with 25 to 40 percent of related compounds, occurring in the normal manufacturing processes, which are toxic to insects." The names "chlordane" and "technical chlordane" were recorded in the Patent Office as of February 27, 19*4-7. Murphy ( 34l ) pointed out that the terminal "ane" in chlordane is misdescriptive as it is properly reserved for saturated hydrocarbons and parent heterocyclic compounds. Chemical Abstracts and the other journals of the American Chemical Society refer to this compound as "chlordan", but the United States Department of Agriculture and industry call it "chlordane". LABELING For the purpose of labeling insecticides under the new Federal Insecticide, Fungicide, and Rodenticide Act, the Production and Market- ing Administration of the United States Department of Agriculture has approved the use of the shortened name - octachloro-4,7-methanotetra- hydroindane. - 5 - It has further ruled that "Technical chlordane is the commercial pro- duct containing 60 percent to 75 percent of chlordane together with 25 percent to 40 percent of other related compounds, ncr mally resulting from the manufacturing processes, and toxic to certain insects. All of its ingredients are, therefore, considered active under the Insecticide Act." SYNTHESIS The synthesis of chlordane is described in patents granted Hyman (23J2, 233 ). It is made "by combining hexachlorocyclopentadiene and cyclo- pentadiene to form a Diels-Alder addition product of the formula C .H^Cl,-, to which chlorine is added to form C^qH^CIs. The reaction is as follows: 010' 01 C / 9 1 HO- -OH cci 2 + EC OH 4 C1C C1C H, 01 0. CC1, c 01 H •CH '? (A) -H 0/ The adduct is dissolved in carbon tetrachloride and treated with chlorine gas with the resultant addition of two atoms of chlorine to the double bond (A) to form chlordane: 010 6 01 C 9 1 0, 3 001, 01 7a CH- ,CH- 3a 3H01 2, CHOI -CH 2 It is of interest to know that Riemschneider and Kuhnl ( 389 ) in Germany claim to have independently discovered the insecticidal properties of chlordane. They were led to prepare it from its structural analogy to cantharidin which they state is a contact insecticide. The structure of cantharidin is: - 6 - H IH 2 % ^— / V^ ,* H One of the insecticides developed by Eiensschneider and Kuhnl, called M-410, is stated to have the same structural formula as that assigned to chlordane. No details are given regarding its synthesis or action on insects but it is claimed to be no more toxic than DDT to mice. ANALYSIS There are no specific chemical and physical methods for determining chlordane. Ard (_22) has described a qualitative test for chlordane in insecti- cide spray oils. The method consists in mixing 1 ml. of the sample in a test tube with 2 ml. of a Cello solve-pyridine (^+0:10) solution and 1 ml. of an approximately 1 N solution of potassium hydroxide in 95 percent ethyl alcohol. When heated in a boiling water bath with occasional agi- tation for 5 minutes, the appearance of a red color indicates the presence of chlordane. A 1-ml. sample of 0.2$ chlordane in a deodorized kerosene base gives a wine-red color of considerable strength, and 1 percent gives an intense dark red color. Very weak colors should be regarded as pos- sibly due to other substances. A confirmatory test for chlordane it the appearance of an odor resembling that of a crude methylnaphthalene when the sample is dehalogenated with sodium in boiling isopropyl alcohol as is done in the determination of total chlorine. Toxaphene is the only other insecticide that yields a similar odor when subjected to this test. Some chemists using Ard 1 s method have pointed out that the red color developed is due to by-products in the technical grade of chlordane and that pure chlordane does not give this color. The method would appear to be applicable, however, if the amount of col or -producing materials were a constant in the commercial product. Alessandrini (iP_) modified Ard 1 s method by substituting ethylene glycol for Cellosolve (the monoethyl ether of ethylene glycol). The coloration produced is less intense than in the original method. The presence of DDT does not interfere with the coloration. Analyses of chlordane formulations by this method and by the deter- mination of total and labile chlorine have been published by Alessandrini and Amormino (ll) . - 7 Another color imetric method for the identification and determination of chlordane specifies that 1 ml. of a 0,1 - 1.0 percent solution of chlordane in ethanol "be mixed with 1 ml. N potassium hydroxide in ethanol and 1 ml. of a reagent prepared "by dissolving 0.1 gram of p-aminophenol in 100 ml. of 80 percent ethanol. When heated to 100° C. for 5 to 10 minutes, the appearance of a "blue color indicates the presence of 1 mg. or more of chlordane. None of the other common insecticides interferes. — Palumho Q5ll. In the laboratories of the Division of Insecticide Investigations, Bureau of Entomology and Plant Quarantine, the total chlorine in chlordane is determined by decomposing the sample with sodium in refluxing anhydrous isopropyl alcohol and titrating the sodium chloride formed with N/10 silver nitrate solution, using an electrometric titrimeter. Chlordane is calculated hy multiplying the total organic chlorine content "by 1.44, a factor "based on the fact that pure chlordane contains 69.22 percent of chlorine. Eomano ( 3 , 98 ) has pointed out that temperature, concentration of chlordane in solvent, and ratio of potassium hydroxide to solvent influ- ence the dehydrohalogenation of chlordane and that a carefully standard- ized method is necessary in order to obtain reproducible results. Eomano refluxes a solution of a 0.5 gram of chlordane in 20 ml. of petroleum ether with 20 ml. of N alcoholic potassium hydroxide at 80° C. for 30 minutes and determines the chloride ~oy Volhard' s method; 1 ml. 0.1 N silver nitrate = ^7»6 mg. chlordane. This factor used "by Eomano is an arbitrary one. The loss of one chlorine atom from the molecule of chlordane, C^oH^Clg, calls for the value 1 ml. 0.1 N silver nitrate = kO.Q mg. chlordane. Davidow (98) in 1950 described a spectropho tome trie method for the quantitative estimation of technical chlordane which is also applicable to the estimation of alpha-chlordane, beta-chlordane, heptachlor, and trichloro 237 (all present in technical chlordane) when only one is present. The procedure is to develop a colored reaction product "by heating chlordane in n-hexane with diethanolamine-potassium hydroxide reagent in a boiling water hath for 30 minutes and note the absorhency at 521 millimicrons in a Beckman spectrophotometer. Technical chlordane interferes in the method for the determination of heptachlor in which equal volumes of the suspect solution and a 0.5 molar solution of ethanolamine and of potassium hydroxide in butyl Cellosolve are mixed and heated in a boiling water bath for 15 minutes, the development of a pink to deep violet indicating the presence of heptachlor. — Velsicol Corp. (*+79~). Chlordane does not interfere in the colorimetric estimation of aldrin in which the aldrin is reacted with phenylazide to form a dihydro- triazole derivative which yields an intense red color when reacted with diazotized dinitroaniline in alcoholic hydrochloric acid. — Danish and Lidov (22). - 8 - PHYSICAL AITD CHEMICAL PROPERTIES Chlordane is a viscous, amber colored, nearly odorless liquid, "boil- ing at 175° C. at 2 mm. pressure. It is insoluble in water and soluble in organic solvents such as aliphatic, aromatic, and chlorinated hydro- carbons, as well as in ketones, esters, and ethers. It is completely mi6cible in all proportions with deodorized kerosene, a solvent widely used for insecticidal products. — Kearns ejt al. ( 2^5 ,); Sun ( 446 ): Vest (496). Its specific gravity range is 1.60-1.635 at 60° F./60° F., equivalent to a weight per gallon of approximately 13*3-13.6 pounds. The refractive index is 1.56-1.57 at 25° C— Bussart and Schor (j&) . It has been reported that Van Dyk 264 (N-octyl-bicyclo[2.2.l]-5- heptene-2,3-dicarboximide) , a synergist for pyrethrins, will dissolve 50 percent of its weight of chlordane. — Anon. Q) . Chlordane dehydrohalogenates in the presence of alkaline reagents with concomitant loss of insecticidal activity. For this reason, it should not be formulated with alkaline solvents, carriers, or emulsifiers. COMPATIBILITY Frear ( 155 ) has published a table showing the compatibility of the common spray materials. Chlordane is represented as follows: Chlordaqe mixed with : Lead arsenate Calcium arsenate Paris green Cryolite Eotentone Pyrethrum Nicotine DDT BHC Toxaphene TEPP Parathion Summer oils Dormant oils Dinitro compounds Lime sulfur Wettable sulfur Lime Fixed coppers Bordeaux Dithioc.orbamatos Compatibility Fully compatible Compatibility questionable Fully compatible Compatibility questionable Fully compatible h u Compatibility questionable Fully compatible Compatibility questionable Fully compatible Compatibility questionable Fully compatible Charts showing the compatibility of chlordane with other insecti- cides were published anonymously (i, $) in the February 1948 and 1949 issues of the American Fruit Grower. Chlordane is represented as doubt- - 9 - ful with "basic lead arsenate, calcium arsenate, 40 percent nicotine, Bordeaux, glyoxalidines, lime sulfur, zinc sulfate plus lime, and lime; and compatible with all other insecticides and fungicides. A mixture of chlordane 50-percent wettable powder with 4-8-8 fertil- izer at the rate of 2 pounds to 1000 maintained insecticidal activity for at least 30 days. — Kelsheimer ( 252 ). Chlordane in certain fertilizer mixtures remained active for 192 days. — Compton (79). Additional observations on the compatibility of chlordane with spray materials have been recorded by Marshall ( 3l6 ): and Griffiths and King (1221. The American Fruit Grower (Anon. 4, £) has published charts showing the weather factors in spraying and dusting fruits with insecticides. Chlordane is listed as safe to apply to both pome and stone fruits under 5 weather conditions: temperature above 85°; temperature 85° to 65*i temperature 65° to 40°; light rain; high humidity with slow drying. FREIGHT CLASSIFICATION Beginning June 1, 1948 chlordane was shipped under a new item - "Polychlor Agricultural Insecticides and Fungicides' 1 in the consolidated freight classification. Polychlor is a name selected by the Classification Committee for a group of compounds, including DDT, benzene hexachloride, toxaphene, and chlordane which contain three or more chlorine atoms. This name is used only for shipping purposes, not for labeling. It was selected to avoid confusion among carriers as well as shippers over the long chemical names of this group of products, whose importance is increasing, and to avoid numerous requests for exceptions for individual products. All items in this group now will enjoy the same freight classification in their territory. Shippers should note that this new item does not cover the technical chemicals which should still be described as "chemicals, noibn"; likewise, it does not cover liquid preparations, or dry formula- tions in excess of 50 percent of the chlorinated chemical. Such formu- lations will continue to be described as "insecticides or fungicides, noibn". — Anon. (2). PATENTS Patents on chlordane have been granted Julius Hyman ( 231-233 ) as follows: Belgium - Patent No. 464,617 granted April 16, 1946. England - Patent No. 6l8,432 granted February 22, 1949. Mexico - Patent No. 45,398 granted March 19, 1947. United States -Patent No. 2,519,190 granted August 15, 1950. - 1. The process disclosed in these patents is discussed under the head- ing "Synthesis" on page 5. The adduct C LCL foraed "by combining hexachlarocyclopentadiene and cyclopentadiefle in the first step of making chlordane has some insecticidal properties. This compound, called chlordene, has been patented for use as an insecticide by the Velsicol Corporation ( 475- 477 ) and derivatives of it, for example, 1-hydroxy chlordene, 1,2- dihydroxy chlordene, and 1-acyloxy chlordene have been patented by Herzfeld ejt aX. ( 213-215 ) assignors to the Velsicol Corporation. GRADES AND SPECIFICATIONS There is only one manufacturer of chlordane, the Velsicol Corpora- tion, 330 East Grand Avenue, Chicago 11, Illinois, which calls its pro- duct "Velsicol 1066". Julius Hyman & Company, Denver, Colorado ; formerly made chlordane which was sold under the trade name "Octa-Klor" . On May 29, 1950 the United States Supreme Court refused to review the case of Julius Hyman, thus making effective a decree affirmed by the Supreme Court of Illinois which enjoins Julius Hyman & Company from making and selling chlordane. The technical chlordane (AG grade) manufactured by the Velsicol Corporation ( 478 ) complies with the following specifications: Property Specific gravity at 60° E./60° F. Weight per gallon (lbs.) Color (G*rdner-Eellige-1933) Viscosity (centistokes at 130° F.) Viscosity (SSU at 130° F.) Total chlorine content ($) Insolubles in deodorized kerosene at 20$ V/V The clarified grade is lighter in color than the AG grade, other- wise, it6 properties are the same. FORMULATIONS OF CHL0RDA12 The manufacturer of chlordane, the Velsicol Corporation, has issued several publications giving detailed directions for the prepara- tion of chlordane formulations and these publications should be con- sulted by those intending to make a chlordane insecticide. Chlordane is commonly employed in the form of solutions, emulsions, dusts, and wettable powders. Liquefied gas aerosols of chlordane have been tested and found to yield promising results. Minimum Maximum 1.600 1.635 13.3 13.6 — 14 45 70 209 324 64 66 — None - 11 - Solutions of chlordane are easily prepared as it is readily soluble in the common organic solvents. It is miscible in all proportions with kerosene. Emulsions containing chlordane can he formulated with or without a solvent (Mail, 311 . 312 ). This is because chlordane is a liquid. The addition of small amounts of oil-soluble emulsifiers to oil solutions of chlordane makes emulsion concentrates which may be added to any desired amount of water. Also chlordane may be emulsified directly in water by the addition of a soluble emulsifier; however, in this case higher per- centages of emulsifier must be used in order to maintain the same cream separation rate as that shown by aqueous emulsions made from oil-contain- ing concentrates. Twenty-two emulsifiers suitable for emulsifying a kerosene solution of chlordane in water are listed by Lidov e_t aj„. ( 298 ) . An emulsifiable concentrate that produces a moderately stable emulsion is made by dis- solving 1 pound of chlordane and 5 ounces of Atlox 1045 A (polyoxy- ethylene sorbitol oleate-laurate) in sufficient kerosene to make 1 quart. When added to water to make a 2-percent wt./wt. emulsion of chlordane, the resulting emulsion will show approximately two percent cream layer after standing 2k hours. Chlordane dusts are prepared by first formulating a 50-percent by weight chlordane dust concentrate and then diluting this to the desired concentration. In preparing the dust concentrate, an absorbent type carrier such as diatomaceous earth should be used, and the impregnation process is carried out in a ribbon type blender. A weighed quantity of the absorbent carrier is placed in the blender, and an equal weight of the insect toxicant (heated to approximately 150° !.) is sprayed by means of air pressure through an orifice directly on the agitated carrier. The spraying orifice should be designed so that a finely atomized mist will be emitted which will cover a comparatively large surface of the carrier, and it should be placed approximately 12-14 inches above the surface of the carrier. If the orifice is at a greater distance from the carrier, the emitted droplets which cool on emission will become too viscous for efficient blending. In addition, if the effective spraying area is too narrow, the droplets will coalesce, and they will not blend satisfactorily with the carrier. The 50-percent dust concentrate is then run through a hammer or attrition mill for additional blending. A non-absorbent type of diluent or filler such as pyrophyllite is used to cut back the dust concentrate to the desired strength. The dustB finding the most universal application are those containing 5 percent and 10 percent by weight of chlordane. Chemicals having an alkaline reaction should not be used with chlordane because such materials can cause de- hydrohalogenation of the insect toxicant. lettable powder - The manufacturing process for this product is the same as that used in preparing the 50-percent by weight dust concentrate. Aerosols - In experimental studies a liquefied gas aerosol formula (G-556) containing k percent chlordane, 5 percent DDT, 5 percent piperonyl - 12 - butoxide, 20 percent Freon-12, 66 percent methylene chloride, and enough carbon dioxide to develop 150 pounds per square inch pressure proved one of the "best when sprayed on aluminum and masonite panels and tested for residual toxicity against confused flour beetles, American roach adult6 and nymphs, and grasshoppers. — Fulton et aj.. ( l60 ) , No aerosol formulas containing chlordane have "been approved by the U. S. Department of Agriculture. Proprietary insecticides that contain chlordane - The Arizona Agri- cultural Experiment Station (2Jj) in 19^8 listed 1C04 products registered "by 101 registrants in that state. Analyses are given of 6 chlordane formulations. Frear e_t al,. ( 156 ) in 19*+9 published a list of active ingredients in trade-marked pest control materials which includes about kO products that contain chlordane. EFFECT ON PLANTS When added to the soil - When chlordane was added to Chester clay loam, Sassafras sandy loam, Eveshoro fine 3and and muck in the greenhouse, it depressed plant growth at relatively low levels without causing any obvious symptoms. Soil type and character, especially the quantity of organic material or colloidal clay present, are important factors in de- termining the toxicity of organic insecticides. Chlordane injures root systems more than DDT does and is more toxic to seedling plants than benzene hexachloride. Chlordane at the rate of 25 pounds per acre severely affected the germination of seeds. — Cullinan (22., 9^0 « When chlordane was added to the soil, it appeared to be toxic to all vegetable crops tested. — Foster (151 ) . Chlordane was mixed with Sassafras sandy loam by atomizing an ace- tone solution onto the soil particles while mixing at rates up to ^00 pounds per acre (based upon 6 2/3-inch profile or 2,000,000 pounds of soil). The treated soil was distributed in 8-inch pots and each pot was planted to three 1-year-old Blakemore strawberry plants. Chlordane did not have any deleterious effect on the growth of the plants. — Goldsworthy (181). Snap beans from plots treated with 297 pounds of chlordane 50-per- cent wettable powder per acre had a disagreeable odor when steamed in cotton-plugged flasks. About four months after treatment of the soil, cowpeas were planted after the beans and okra were removed. The vigor of the plants was much better than in untreated soil and these differ- ences were not the result of root-knot which was quite severe OB prac- tically all the plots.— Ellis and Claytcn (17?) . At Corvallis, Oregon, in 19^7, a 5-percent chlorcane-talc dust at the rate of 27.5 pounds of toxicant per acre applied to the soil with a fer- - 13 - tilizer spreader produced slight stunting and chlorosis of lima "beans. — Chlordane was less toxic than benzene hexachloride (10-12 percent of the gamma isomer) to nitrifying bacteria and fungi when added to greenhouse soil at 100 and 500 pounds per acre. — Smith and Wenzel ( 426 ) ♦ In tests at Bradenton, Fla», 50 pounds of chlordane per acre did not affect the germination of cabbage, lettuce, tomato, eggplant, and pepper. Chlor dan e 50-percent wettable powder mixed with 4- 8-8 fertilizer at the rate of 2 to 1000 proved safe to use for a period of at least 30 days. Tomatoes grown in soil treated with fertilizer plus chlordane germinated normally. However, application of chlordane on tobacco seed- beds completely destroyed the germination. — Kelsheimer ( 252 ) . In tests at Belle Glade, Fla. , chlordane either as a 5-percent dust or as a 40-percent emulsion was mixed with an 0-12-16 celery fertilizer and raked into the soil in amounts equivalent to from 2,4 to 15 pounds of toxicant per acre. Cabbage, pepper, tomato, and bean planted as seeds grew well in all plots; and none of the soil treatments gave any undesirable taste which could be detected in the raw cabbage. — Hayslip (211). In IT.or Ida four pounds of chlordane per acre (in the form of a 50- percent wettable powder) increased the germination of sugarcane cuttings. Observations were made 19, 33, and 63 days after planting. — Bourne (42). In Washington a reduction in stand of cucumber seedlings 14 days after planting was highly significant for treatment of soil with chlor- dane at the rate of 34.8 pounds per acre. This amount of chlordane also caused a lower stand of bush beans and turnips. So significant differ- ences were found for any vegetables (bush bean, pole beans, beets, carrots, cauliflower, cucumbers, onions, squash, and swiss chard) tested in treatments of 5 pounds chlordane per acre. Chlordane seemed to reduce the quality of the fresh peas, pole beans, ana bush beans, but was ques- tionable for carrots and cucumbers. — Stitt and Evanson ( 44l ) , In Connecticut tests with potatoes grown in soil treated with chlordane at rates of 1, 2, 4, and S pounds per acre were inconclusive, but any resulting flavor from chlordane was ranch less objectionable than the flavor of benzene hexachloride. — Greenwood and Tice (196) . When applied directly to -plants - In Hew Jersey established turf of various grasses and clover was sprayed with chlordane at the rate of 25 pounds per acre (50 pounds of 50 percent wettable powder per 1000 gal- lons of water), 2.5 time3 the rate used for control of Japanese beetle larvae. At intervals after treatment the grass was cut and weighed. The chlordane had no effect on the color, general appearance, or growth of the following grasses: redtop, Colonial bentgrass, Astoria bentgrass, 3ermuda grass, orchard grass, meadow fescue, Chewings fescue, perennial ryegrass, Canada bluegrass, Kentucky bluegrass, and rough stalk bluegrass. UBRARY STATE PLANT BOARD - 124- - In addition to these grasses, white clover grew normally. In field test6 at five localities there was no indication that the application of chlordane at the rate of 10 pounds per acre had any adverse effect on the various grasses and clover. — Fleming ( ^39 )« In tests in Florida in 19*+7 and 19*48, 5-percent chlordane dust and 50-percent chlordane wettable powder at 2 pound s per 100 gallons of water reduced the yields of cucurbits; in one case the dust reduced the yield of cucumbers below that of the check plot. — Kelsheimer ( 255 ; . Chlordane should not be used on cucurbits. — Schread (40^). In experiments at Geneva, New York, a dust containing 5-percent of chlordane produced characteristic symptoms of foliage injury on Blue Hubbard, Table Queen, and Butternut squash, representing the plant species Cucurbit a maxima, C. p epo . and C± qpschata . The injury was later outgrown and did not appear to affect the yield. — Carruth and Howe (66). In Florida chlordane gave good control of insect pests of cucumber and squash without reducing yields in several tests, but in the fall of 19*+7, a wet season, it severely reduced the yield,— -Kelsheimer ( 25*4 ) . In tests on curcubits in Oregon 5-percent chlordane dust, under moist conditions, caused slight burn on 2 varieties and chlorosis on 11 varieties. — Crowell and Morrison (90) » Peaches sprayed with nothing except chlordane developed foliage injury in June similar to what has been called Bacterium pruni. — Marshall (315). Chlordane spray gave little if any protection against peach scab in West Virginia, but did not injure the fruit or f oliage.-- Gould and Taylor (182.) . Chlordane 50-percent wettable powder at 2 pounds per 100 gallons of water was sprayed on peaches in North Carolina in 19*48. Fruit from the chlordane plot was by far the best in two tests, but in another test it was even significantly worse than fruit which had received four applica- tions of benzene hexachloride. — Smith ^t_ al. ( 4 20 ) . Chlordane emulsion, 0.5 pound toxicant per 100 gallons, caused moderate injury to Kalanchoe global If era coccinea (referable botanic- ally to Kalanchoe blossf eldiana) . — Lumsden and Smith ( 303 ) . In North Dakota in 19*48, a 5-percent chlordane dust at 35 pounds per acre gave the same yield (lkk bushels per acre) of potatoes as did a 5-percent DDT dust. The untreated plot yielded 126 bushels per acre. — Munro ejt al. (3*40). In North Dakota in 19*+7, a 5-percent chlordane dust gave a potato yield of 2o0 bushels per acre compared to 239*9 bushels per acre for the - 15 - untreated plot. There were 5 applications of dust at the rate of 20 pounds per acre application. — Post £t al,. ( 370 ). In tests on Red Warba potatoes in Winnipeg a spray of chlordane wet- table -powder yielded 317*2 "bushels of potatoes per acre as compared to 83.7 in the check. A chlordane emulsion spray was somewhat less effective. None of the insecticides tested (toxaphene, chlordane, and DDT) impaired the flavor of potatoes tested as "boiled potatoes and none of them injured the potato foliage. — Mitchener ( 330 ) . In New Jersey field tests potato plots sprayed with 50-percent chlordane at the rate of 2 pounds to 100 gallons of water, gave a lower yield than plots sprayed with the same dosage of 15-psrcent parathion or 25-percent benzene hexachloride. — Campbell ( 64 ) . Additional observations of the effect of chlordane on plants have been recorded as follows: No effect on the flavor of apples (Weinman 486 ): no phytotoxicity to the apple tree (Frezal 157 ): no injury to asters (Jefferson and Pence 239 . 240 ): imparted a flavor to dried beans (fiistich and Schwardt 394 ) ; chlordane dust caused slight injury to the new growth of cantaloupes and cucumbers (Brooks and Anderson 48); chlor- dane emulsion applied to corn ears imparted an odor noticeable at har- vest (Blanchard and Chamberlin 25); four dustings with 5-percent chlordane injured the corn (Tissot and Kuitert 456 ): potatoes grown in chlordane treated soil showed no off -flavor (Kulash 278 ): chlordane wet table powder spray severely burned the foliage of the Concord grape (Cox 84.) ; and the foliage of prunes and also retarded growth of the tree and development of fruit (Cox8_5j; did not injure red clover (Marshall et al. .214.) j chlordane emulsion caused some injury to sweet potato foliage in the greenhouse (Harrison 206) : at prescribed dosage levels chlordane did not injure grass but at extremely high levels (up to 150 pounds per acre) clover and bent grasses were retarded temporarily (Schread 409, ) . EFFECT ON ANIMALS Earthwo rm Chlordane 50-percent wettable powder at 1/4 pound per 100 gallons of water reduced the earthworm population of the fairway of a Florida golf course, but the control was not considered satisfactory. — Hayslip ( 21l ). Snail A 5-percent chlordane dust proved unsuccessful against Otala lactea . the milk snail, in the San Francisco Bay area in 19^7. — Armitage (25). Black widow spider For black widow or other spider control, a light dusting of the area near where the webs are found is sufficient. The chlordane-impregnated - 16 - dust settles on the web and the spider's first contact proves fatal. — Gilbert ( 17*+) . Fish Chlordane is less toxic to fishes than is DDT hut more toxic than benzene hexachloride. Applications of 1 pound to aa acre to outdoor ponds killed 87 percent of the blue gill sunfish. With applications of 0.5 pound to an acre most of the bluegills as well as other species survived, and with those of 0.25 pound to an acre practically all fishes survived. A 12-percent chlordane solution (wt./vol.) in fuel oil was used in all applications. — Linduska and Surber ( 299. ) . Chlordane of 0.125 p. p.m. killed 100 percent and 0.05 p. p.m. killed 50 percent of goldfish in 4 days. The corresponding figures for DDT were 0.25 and 0.125 p. p.m. — Ginsburg (175 ). Chlordane is less texlc to fishes than toxaphene. At Leetown, West Virginia, recent tests at 0.0^4- p. p.m. in still water failed to kill several species of warm water fishes, including bluegills, goldfish, and several minnows. Toxaphene killed all the fish tested at that strength. Chlordane at 1 pound per acre (in this case 0.16 p. p.m.) killed 87 per- cent of the bluegills tested. In streams and troughs in Alaska, chlor- dane proved to be more toxic to trout than DDT and similar to toxaphene in emulsion form in 15-minute treatments. As a suspension it was not toxic to trout in any strength tested below 15 p.p.m. , and in fuel oil solutions up to 6 p.p.m. no damage was noted. It is concluded that chlordane appears to be damaging to some fish at 1 pound per acre. — Cope (80). At a routine dosage of 0.1 pound per acre, chlordane is toxic to fish and will significantly reduce the population of ponds. At dosages of 0.05 pound per acre, DDT appears to be somewhat more toxic than chlordane. Chlordane appears to have no significant effect on the fish population at a dosage of 0.025 pound per acre. These tests were made on 32 species of fish in ponds. — Tarzwell ( ^52 ) . Birds Chlordane appeared to be l/k to 1/2 as toxic as toxaohene to game birds. —Post (369). Mammals (a) Hats and. Mice - In tests made at the University of Illinois, chlordane and DDT appeared to be of the sane orde^- of toxicity to white rats, when adninistered as acute and repeated intragastric dosages and when inuncted percutaneously as an oil solution, emulsion concentrate and dilutions of the emulsion concentrate. Eats receiving either chlor- dane or DDT present a wide range of individual susceptibility, which makes it difficult to establish an absolute minimum or median lethal dose. Anorexia, los3 of weight, hyperexcitability , and tromors were symptomR produced by both conroounds. Tonic and clonic contractions were slightly - 17 - more severe for those treated with chlordane. The time lapse "between administration of an acute lethal dose and death is longer for chlordane than for DDT treated rats. There is some indication that chlordane may he slightly more toxic to female rats than to males. This was not ob- served to he true for DDT- treated rats. Chlordane appears to produce in rats less liver damage, hut greater pulmonary damage than DDT. — Ingle (235). Pharmacologists of the Food and Drug Administration found that the acute oral toxicity of chlordane to rats was LD-50 500 mg./kg. t indicating that it is 1/2 as toxic as DDT. Chlordane is quite toxic when fed to rats at a concentration of 250 p.p.m. for 12 weeks. Rats have "been seriously injured at this level and fail to survive on higher concentrations. Chlordane is a liver poison and also causes inanition in chronically poisoned animals. — Lehman ( 287 . 290 .) . Chlordane is absorbed by the animal but its fate and whether or not the chemical is excreted in the urine is unknown. — Woodward et al. ( 509 ) . No harm resulted to rats, mice, or guinea pigs when they were sub- jected for 45 minutes on each of 38 days to air bearing aerosols contain- ing chlordane with methylene dichloride or dimethyl phthalate as solvents, the average initial concentration of chlordane being approximately 1.9 mg. per liter. When aerosols with either kerosene, methylene dichloride, or dimethyl phthalate as a solvent were introduced into the chamber at inter- vals of 10 minutes over an hour in an initial concentration of 10 mg. of chlordane per liter, and this procedure was repeated three times on each of four successive days, many of the animals exhibited typical signs of poisoning by chlordane. — Heyroth and Witherup ( 217 ) • Stohlman et a^. (V+2, 443 ) reported that the LD-50 of chlordane when fed to rats is 250 mg./kg. compared with 150 mg./kg. for DDT. Rabbits receiving chlordane excrete organically bound chlorine in the urine. The LD-50 of chlordane when administered intraveneously to rab- bits is about 20 mg./kg. and this is increased to about 60 mg./kg. through the antidotal action of the barbiturates. Frings and 0'Tousa ( 153 ) reported that chlordane is very similar to DDT in its toxic action in mice. The first system affected in the nervous system, and nervous symptoms predominate in acute toxicity. In chronic intoxication, however, the liver seems to be most affected. The vapor of chlordane was toxic and wettable powder preparations proved surprisingly toxic. (b) Dogs - Dogs starved for Ik hours were fed a 50-percent chlordane wettable powder in capsules with oil. It was concluded that chlordane, like benzene hexachloride, is a relatively safe insecticide to use upon dogs. Dogs vary in their susceptibility to chlordane. A dose of 200 mg./ kg. produced convulsions in one dog, while a 700 mg./kg. dose had little effect on another dog. — Batte and Turk (29,) . - 18 - (c) Sheep. Cattle, Goats. Horses, and Pigs - Chi or lane appeared from two to four times more toxic than DDT to sheep in acute toxicity. Sheep grazed on pastures sprayed with technical chlordane at rates up to 4 pounds per acre showed no apparent ill effects. — Hinnan and Cowan ( 21 3 ) . At Bozeman, Montana, the maximum safe, single dose of chlordane for sheep appeared to "be considerably less than 0.5 g. per leg., and for cattle no toxic effect was produced "by 0.05 g« per ^£« The effects of daily dosages of chlordane administered in capsules for 60 days were: a capsule of 4.5 grame of a mixture of chlordane and xylene (3«5 grans chlordane) was extremely toxic and half this dosage proved about as toxic. A dose of 1 gram of chlordane-xylene mixture (0.?7 grams chlordane) was con- tinued to the end of the experiment producing only mild symptoms. Sheep dosed with capsules containing 2 grams of xylene alone gave no reaction, indicating that the chlordane was the toxic agent. Six sheep grazed for 21 days immediately following spraying of 1 pound and 4 pounds chlordane per acre showed no indication of toxic effect. — Welch ( 491 ) . Wet table powders containing less than 1 percent of chlordane had no ill effects on cattle, sheep, goats, hogs, and horses. — Laake (230) . In toxicological experiments with chlordane at Kerrville, Texas, dipping goats or sheep with chlordane wettable powder or emulsion did not cause symptoms of poisoning until after six to eight dippings in 1.5-per- cent chlordane at 4— day intervals. Marked symptoms of poisoning developed in all animals after the last dipping and fatal results ensued. Cattle likewise failed to show toxic symptoms until after four sprayings at in- tervals of 2 weeks with 2 percent chlordane wettable powder suspension when severe symptoms occurred followed by death. The dip and spray liquids were six and eight times the recommended strength, respectively, and the frequency of application was much greater than in actual field practices. Acute poisoning is characterized by sudden onset, with bleat- ing, groaning, grinding the teeth, blindness, violent struggling, and bluish discoloring of the skin before death. In subacute and chronic poisoning the onset is gradual with partial to complete blindness and locomotor ataxia, circling, staggering, avoiding imaginery objects, and periodic convulsions. Post mortem findings consist of petechiae and larger hemorrhages under the serosa of the large and small intestines and the epicardium, fatty changes of the liver, and congestion of the brain. — Hadeleff Q8l). Bushland et al . (38) U. S. Bur. Animal Ind. (464). U. S. Bur. Ent. and Plant Q,uar . (4&3). (d) Man - Undiluted "Velsicol 1068" caused mild irritation of human skin, under the conditions represented by conventional 43-hour patch tests upon 58 subjects. When diluted in mineral oil and employed in 48- hour patch tests in a 1 percent (by volume) solution, "Velsicol 1068° caused no irritant effect. — Goldman ( l80 ) . Chlordane applied to the skin causes moderate irritation; the (quantity considered dangerous upon skin application in solution is for single exposure 1880 mg./kg. and for multiple exposure 40 mg./kg. The The quantities dangerous to man are: for sinrle exposure 113 grams and - 19 - for multiple exposure 2.4 grams per day. The hazards of aerosol formula- tions of chlordane can only be surmised.—- Lehman ( 288 ) . On the West coast only one case of dermatitis among pest control operators using chlordane has "been reported and the patient in the patch test showed sensitivity to both petroleum solvents and undiluted chlordane. It is concluded that chlordane is probably no more hazardous than many other standard products used in the industry. — Jacobs ( 238 ) . The council on Foods and Nutrition of the American Medical Associa- tion (17) in a recent statement called attention to the danger to public health created by the wide use of synthetic insecticides and urged that controls be placed on the sale of products of unknown or incompletely known toxicity. The effects of inhalation and skin absorption of these synthetics must be determined as well as their chronic toxicity to man. Toxicological information on chlordane has been summarized as follows: Iio cal effects ; - Chlordane is moderately irritating to the skin. This property is lost on dilution, as in insecticide formulations, and the warning sign of danger is lost. The insecticide is absorbed through the skin, and it has been estimated that daily exposure to about 2. k grams in solution may be dangerous to man. S ymptoms : - The early signs are those of irritability of the central nervous system. This leads eventually into convulsions, which are followed by a period of de- pression with or without a final convulsion seizure. Fatal dose ,: - From the acute standpoint chlordane appears to be only about one-half as poisonous as DDT, but the side effects are such that in the final analysis the toxicity is about 5 times that of DDT. Therefore, the fatal dose lies somewhere between 6 and 60 grams. Fatal period : - The onset of symptoms is within 45 minutes after ingestion. Deaths occur occasionally within 24 hours, are frequent between the 48th and 96th hour, and if sur- vival extends to the 6th day, recovery is the rule. Pathology ,: - Inani- tion is a predominant observation in chronic poisoning, indicating a con- siderable disturbance in normal physiology. Of the vital organs, the liver bears the brunt of the poisoning, and the usual degenerative changes produced by chlorinated hydrocarbons are a constant finding. Treatment : - The usual measures should be adopted for removing the poison from the stomach and intestinal tract. Any additional treatment must be sympto- matic as no specific antidotes are known.— Lehman ( 290 ) . A comparison of the acute oral doses shows that the compounds arrange themselves in the following order from the most toxic to the least toxic: tetraethyl pyrophosphate, parathion, hexaethyl tetraphos- phate, toxaphene, gamma isomer of benzene hexachloride, DDT, chlordane, TDE, methoxychlor . Chronic feeding data indicate that parathion is the most toxic, the sequence being parathion, beta isomer of benzene hexa- chloride, chlordane, DDT, gamma isomer of benzene hexachloride, alpha isomer of benzene hexachloride, toxaphene, TDE, delta isomer of benzene hexachloride, methoxychlor. — Lehman ( 289 ). Additional reports on the toxicology of chlordane have been pub- lished by Lehman ( 291-295 ). Chlordane presents the greatest all-around hazards of the commonly used chlorinated insecticides and therefore has - 20 - no place as a contaminant of foods and its household use should he strictly limited. Long-term feeding studies indicate that at every level of feeding chlordane is significantly more poisonous than comparable levels of DDT. From the over-all aspects chlordane is at least k times as toxic as DDT. SPRAY RESIDUES OF CHLORDANE In Colorado, Gates (l2Zl in 19^8 1 found chlordane residues on alfalfa after the application of one pound of the toxicant a6 an emulsion per acre as follows: cut 8 hours after treatment 17*9 p. p.m., 5 days 13 p. p.m., 10 days 4.5 p. p.m., and 15 days after treatment 3*^ p. p.m. A test on houseflieB with an extract of the hay cut the first day indicated a chlor- dane residue one-half that calculated from the total chlorine content. When chlordane was applied to apple and peach foliage at the rate of 1 pound (an emulsion concentrate) per 100 gallons of water, the initial deposit was 90.2 p.p.m. on apple foliage and 139»5 p. p.m. on peach foliage. After 21 days these values fell to 8.3 p.p.m. and none, respectively. Residue determination on alfalfa, sweet clover, red clover, and soy beans indicated that lindane and parathion residues are the least persistent followed by aldrin, chlordane, dieldrin, toxaphene, and DDT in that order. The waxy nature of chlordane residue makes it resistant to removal by rain. Chlordane residues were determined by the total chlorine method using the factor Cl x 1.57 = chlordane. — Decker ejt al,. (101 ). Chlordane in milk - A spray containing 0.5 percent of chlordane as a wettable powder was sprayed on milk cows four times between May 15 and August 29. Milk from these cows sampled from May 22 to October 27 showed a maximum organic chlorine content of 0.8 p.p.m. and an average of 0.2 p.p.m. It was concluded that these amounts are so small that they are not regarded as definitely indicating the presence of chlordane in the milk. —Carter ejfc, a^. (67) . The danger of chlordane in milk to the public health was recognized by the United States Production and Marketing Administration (^2J±) which on May 12, 19^9 sent a notice to manufacturers, registrants, and dis- tributors of insecticides containing chlordane warning against the use of chlordane on dairy animals, or on forage or other feeds for dairy animals or animals being finished for slaughter, or fox use as insecti- cides in dairy barns. The American Medical Association (l6. 17 ) has expressed concern over the contamination of the American diet with new materials of unknown toxicity such as chlordane and has urged that voluntary control by the producers and distributors of the pesticides be instituted immediately. - 21 - INSSCTICIDAL USES OF CHLORDANE The literature records the results of tests of insecticides contain- ing chlordane on the following kinds of insects and other arthropods: Class and Order Families 3 Genera Species Orthoptera 14 21 Isoptera 2 2 2 Thysanoptera 1 5 5 Anoplura 2 3 5 Mallophaga 3 6 8 Homoptera 8 19 22 Heraiptera 5 16 19 Coleoptera 12 42 45 Lepidoptera 11 31 37 Hymenoptera 4 12 17 Dipt era 12 20 39 Siphonaptera 1 1 - Acarina 7 12 16 Total 71 183 236 DLPLOPODA Millipedes Chlordane, 1 pound per acre, had little effect on millipedes in grain fields. — Severin ( 4l4 ) . SCOHPIONIDA Scorpions In Arizona a 2-percent solution of chlordane in oil killed scorpions in from 12 hours to 3 days. Chlordane killed more quickly than DDT, hut did not last as long. The "best all around mixture for scorpion eradica- tion at present seems to he 2 percent chlordane, 10 percent DDT, and 0.2 percent pyrethrins in an oil spray-hase. — Stahnke ( 437) » ORTHOPTERA Acrididae Grasshoppers are readily killed by the application of chlordane and it is used on a large scale for their control. There appears to he little difference among species in their susceptibility to chlordane and because - 22 - of this the results of tests with one species are about the same as those with another. Severin (i&Ji) reported chlordane to he effective against 35 species of grasshoppers. fielative toxicities of chlordane and other insecticides to frass- hp-p-pers - In the laboratory Koarns e_t &1.. ( 2^5 ) made stomach poison testa with chlordane, DDT, and gamma-BHC on the adult grasshopper Melanoplus differentialis (Thos.). Emulsions of xylene solutions of the active com- pounds were fed to the grasshoppers in measured drops. Twanty-four hour mortality records indicated the median lethal dosage for gamma-BHC to lie between 5 ^ad 10 micrograms, for chlordane between 12.5 and 25 micrograms, and for DDT to be greater than 50 micrograms per gram of body weight. Ehoades and Brett ( 3&3) made laboratory tests on three economic species of grasshoppers, Melanoiolus bivittatus (Say), M. djff erentlalis (Thos.), and M. mexicanus mexicanus (Sauss.), to deterrr.ine their suscepti- bility to certain synthetic insecticide dusts under different constant temperatures. A 10-percent chlordane dust was slower acting than 2— per- cent parathion and 5-parcent gamma-BHC dusts, requiring from 43 to 72 hours to reach peak mortality. High temperature increased its effective- ness to a lesser extent. Chlordane was less effective than the other materials except DDT in its action as a contact toxin. There was little difference in the relative susceptibility of the three kinds of grass- hoppers to the different insecticides. In laboratory tests against Zpnocerus elegans (Thunb.) by Petty ( 363 ) in South Africa a 2-percent parathion dust proved superior to a 5-percent chlordane dust. In general, 10-percent BHC causes a quicker rate of mortality than 5-percent chlordane, although the final mortality obtained with the two insecticides is similar. A 5-percent BHC con- centration appears to be too weak for effective control and 10-percent DDT is relatively ineffective. There is some indication that young hoppers are more susceptible to the poisons than the older ones or adult insects. The results suggest that a 5-percent chlordane dust should be effective at the rate of 20 pounds per acre. LePage e_t ai.. ( 297 ) in Brazil, using Schistocerca caacqllata. (Serv.) as the test insect, found that a 5-percent chlordane dust was more toxic than dusts containing 10 percent of dinitro compounds or 20 percent of toxaphene but was less toxic than dusts containing 0.25 percent para- thion, or 1 percent of gamma-BHC. Kearns e_t ai.. ( 246 ) made laboratory tests on the grasshopper (}{, differential^ ) . housefly, American and German roaches, milkweed bug, codling moth larvae, black carpet beetle, webbing clothes moth, plum curculio, chinch bug, and two-spotted mite with several insecticides. The relative toxicity of these materials was: dieldrin^> aldrin = hepta- chlor ■ gamma benzene hexachloride > chlordane > toxaphene > DDT. The residual effectiveness of the materials was: dielirin> DDT >aldrin.> heptachlor = chlordane.^ gamma benzene hexachloride. ... 23 - Weinman and Decker (48$) in Illinois conducted one-quarter acre plot tests against 3 species of grasshoppers, Melanot)lus differential is, M» fQm ur, rubrum (Deg.), and M. q exicanus . One pound of chlordane was about as effective as 2 pounds of toxaphene and was more rapid in action. Toxaphene showed a somewhat longer residual action than chlordane at rela- tively high dosages. The LD-50 values for chlordane against M. differen- tial is adults when tested for contact effect were l6.3 in 19*47 and 9.3 in 1948; when tested for stomach-poison effect, the values were 21 .8 and 12.. In these tests parathion and the gamma isomer of BHC proved more toxic and toxaphene and DDT less toxic than chlordane. There was some evidence of slight synergism in mixtures of DDT and chlordane. The greater the ratio of DDT to chlordane, the greater the synergism. Gaines and Dean ( 1.69. ) in Texas determined the relative toxicity of certain insecticides to first to third instar nymphs (M. d iffer ent ial i s ) when applied as contact sprays and dusts to be as follows: MLD. poun ds active ingre dient s per acre Treatment Spray emul sions Dust Toxaphene 1.17 1*73 Chlordane *U$ 1.49 Parathion .05 .17 Benzene hexachloride .04 17 Lindane .08 , The materials applied as sprays made from wettable powders were as effective as when applied as spray emulsions made from miscible oil con- centrates. However, the dosages required to kill adults were consider- ably higher than those required to kill the first and second instar nymphs. In the field tests chlordane and toxaphene were approximately equal in toxicity to young grasshoppers when applied as spray emulsions. Dieldrin was more toxic to grasshopper nymphs than benzene hexachloride, chlordane, aldrin, or toxaphene. Chlordane was first tested against grasshoppers in the field in the summer of 194-6. A dust containing 5 percent of chlordane applied at the rate of 25 pounds per acre killed more than 90 percent of the grasshoppers in a Missouri apple orchard and prevented re-infestation for 30 days. — Wingo et al. (501,). Numerous field tests of chlordane against grasshoppers have been con- ducted in Argentina (Parker, 356 ). Canada (Putnam, 379 ) . South Africa, Australia, Salvador (Zuniga et al . . 52u5) » SXi ^- many of the states. The following report by Parker ( 357 ) « of the U. S. Bureau of Entomology and Plant Quarantine, of field tests made in Arizona, California, and Montana in 1947 presents results typical of those found by other workers. When applied in sprays or dusts, chlordane and toxaphene caused high mortalities within 24 hours and continued to kill over a period of 1 to 4 weeks. Each of these materials was as effective in oil solutions as in emulsion and when applied from the ground as from airplanes. Chlordane at 1 pound per acre in such formulations reduced grasshopper populations 90 to 99 percent in 3 days or less. A suspension at this dosage gave 90 percent kill, and duet a avera at kill when applied by airplane and 64 percent by ground equipment. In field to bh bp-its C.5 pound of chlordane , 1 pound of toxapheno, 1 pound of y :on, or 0.1 pcund of the gamma isomer of 3HC per 100 pounds of carrier gave 10 to IS per- cent higher kills than 6 pounds of sodium fluosili- ate* Chlordane, applied as an emulsion at the rate of 1 and 1.' pc vnds per acre to roadside and field vegetation in Kansas, caused an average reduction of 84 percent in grasshopper population at the end of 72 hours and 100 percent at the end of 7 days. — Butcher ejb al,. (o0) . In testa made at Fort Collins, Colorado, in 1946, chlordane gave nearly 100 percent control in 3 days or less when applied as a f-percent dust at 20 pounds per acre, or as a spray, 2 pounds per 100 gallons, at 50 gallons per acre. For use as a spray 1 pound of chlordane was dis- solved in 1 quart of xylene with 50 cc. of Triton X-100 and this then added to 50 gallons of water. — Weihing and Hoerner ( 485 ) . Aerosol formulation G-556 containing 4 percent chlordane, 5 percent DDT, 20 percent Freon-12, 5 percent piperonyl butoxide, arid 66 percent methylene chloride killed 50 percent of grasshoppers, confused flour beetles, and American cockroaches when they were exposed to ^J-day old residues of it applied at 75 mg./sq. ft. of DDT. The kill was increased to about 80 percent when the residue was tripled. — McBride et al . ( 30 . 5 ) . Reports of tests of chlordane against the f ollcvirig species of grasshoppers have been published: Aeolopus turnculll brunerl Caud., the thistle grasshopper Butcher e_t aJL. (6C) . C.amnula pellucida (Scudd.), the clear -winged grasshopper Arrr.itage (2£) , Hinncn and Cowan (2l8) , Parker (357). Wilson (497). Chcrtoicetes termlnifera (V»1k.) Allman and Wright (l_£) . Hesperotettix speciosus (Scudd.) Butcher et, al . (c0) . Brachystola ma^.na (Gir.), the lubber grasshopper Sevorin ( 415 ) . Mel anoplus bivittatus (Say), the two-striped grass' Brett and Rhoades (4£, 4£) , Butcher et al . (6o) , List and Hoerner (301). Munro et al. (337) . Ehoa ad Brett (?"c) . Severin ( 4L3 ) » H m di:: pr.'ntialis (Thos.) , the differential grae opper Armitage (2£) , Brett and Rhoades 6*5) . . ( 6o) , Gaines ( 1 63 ) , Gainer pan (1 66 ) , Qrahao ( lpO ) , Hinman • Cowan ( 21c ). Kearns e_t al. (246) , I [earner ( 3.01, ) . I (357). Ehoades and Brett (338), Severin ('.13), S tfeJ nd Decker (438, *J89 J. Weiffl ■?) . ''. fenmr-rubxuB) (Deg.), the red—] Armitage l25). Butcher et al. ( 60) . , Cowan (_\ ,, Eutaon (Cjo), List and Hot Parker (152), Severin f5l3 ). Sun e£ j_l- (ifcSfi), ' 57, Weinman si fil« - 25 - M, marginatu s Scudd. Armitage (25) , Parker (152), Wilson G&Z). M. mexicanus devastator Scudd., the devastating grasshopper Hinman and Cowan ( 21 , 8 ) . M. mexicanus mexicanus (Sauss.), the lesser migratory grasshopper Armitage (25), Brett and Bhoades (ij£) , Butcher eji, aJL. ( 60) , Brown (ij£) , Brown and Hurtig (il) , Hinnan and Cowan ( 218 ) . Munro et al. (222), Parker (25Z), Bhoades and Brett (288). Severin (413). Schistocerca american a (Drury). the American grasshopper Griffiths and King &2£), Griffiths fit &. (128), King and Griffiths (262), Thompson and Griffiths (454) . Zonocerus elea ans (Thunb.) legans M)T Petty (363 Chlordane has "been recommended for the control of grasshoppers by the state entomologists of California (25) , Georgia (382). Illinois (2J4) , Indiana ( 375-378 ). Missouri Q28, 2§i) . Oklahoma (222) , South Dakota (4l6) , and Wisconsin ( 5 , 03 . 505 ). Young grasshoppers may "be controlled "by 1/2 pound of chlordane per acre hut the full grown ones require 1 pound per acre. Emulsions have given the "best results, water -wet table powders have been next, and dusts have been least efficient. The dusts wash off more easily than the other two. If sprays have time to dry, they will not wash readily. The treatments will remain effective for about 10 days. The U. S. Bureau of Entomology and Plant Quarantine in February 1950 recommended chlordane for grasshopper control; 0.5 to 1 pound per acre when applied as a spray and 0.75 to 1.5 pounds per acre when applied as a dust. In the bran-sawdust poison bait mixture 0.5 pound of chlordane may be used in place of 6 pounds of sodium fluosiiicate. — Wakeland and Parker (258, Ijgfi, 481 ). Blattidae Blattella germanica (L), the German cockroach Purified chlordane dissolved in a mixture of 4 volumes of reagent grade benzene and 1 volume odorless kerosene and tested for direct con- tact toxicity on 4th and 5th instar nymphs caused 100 percent mortality at 20 micrograms per square centimeter. The median lethal deposit (LD-50) was 1.7 micrograms per sauare centimeter. — Erown, Wenner g and Park Q2). When applied directly to adult female roaches chlordane gave 87 per- cent mortality when a 5.0-percent dust was used with a deposit of 3.0 micrograms per square centimeter. In container dusting a deposit of 0.5 micrograms per square centimeter of a 0.5-percent chlordane dust with a deposit of 0.75 micrograms per sojuare centimeter gave a mortality of 90.0 percent. DDT and sodium fluoride were less toxic and gamma-BHC was more toxic than chlordane. — Kiswander and Davidson ( 352 ) . - 26 - When tested in the form of deposits, chlordane paralyzed roaches more quickly than DDT and toxaphenc , "but less quickly than gamma-3EC. — Hanman ( 202 ) . Residue tests were made by placing the insects on crystalline de- posits of the compounds on filter paper, deposited from standard acetone solutions. Chlordane and gamma "benzene hexachloride were about equal in toxicity and each was more than 1,000 times as toxic as DDT. A chlordane residue of 1.3 micrograms per square centimeter killed 70 percent of the roaches inl20 hours. — Metcalf ( 3 , 2,3 ) . Adult German and American cockroaches were placed for two hours on pieces of cotton twill cloth that had been impregnated with acetone solu- tion of the test material at the rate of 200 mg. per square foot. Gamma benzene hexachloride was the best of the materials during the first week and was outstanding on 5-hour knockdown, but it had lost most of its toxicity by the 28th day. Chlordane was effective when fresh and was somewhat more lasting than the other materials, although it was not highly effective after 28 days. DDT and toxaphene did not give high kills from 2-hour exposures even when freshly applied. The American cockroach appeared to be somewhat more resistant than the German cock- roach to gamma benzene hexachloride and chlordane, but showed less re- sistance to DDT. Chlordane and gamma benzene hexachloride sprayed at the rate of 100 mg. per square foot on the walls of kitchens infested with cockroaches (chiefly Blattella germanica with P. americana ) eliminated a high proportion of the roaches, and the rooms did not become reinfested with this species during the subsequent observation period of 8 weeks. Solutions of chlordane and a mixture of chlordane and DDT, when dispersed by means of a thermal fog generator, effectively controlled cockroaches, but a similar treatment with DDT alone was much less successful.— Gahan et al. (162). Chlordane should be applied at about 500 mg. per square foot. The apparent greater effectiveness of chlordane over DDT may be due to the persistent sticky nature of the material coupled with a slight fumigating property. — Kruse ( 269 ) . In laboratory tests chlordane at 2-percent strength in oil solution was more effective than a 10-percent DDT powder .--Gould ( 183 . 18U . 189). Five gallons of a 2-percent chlordane emulsion applied with a Ses- Kil aerosol generator to a building gave practically 100 percent control, and only a few roaches had reappeared k months later. — Sorasen and Munro too). Perlplaneta a mericana (L.), the American cockroach The relative toxicity of chlordane and DDT to the American roach was determined by applying precisely measured dosages to the thoracic territes. Dosage mortality curves plotted from data obtained in these tests showed chlordane to be approximately three times as toxic as DrT to this insect. The LD-50 for chlordane was found to be approximately Ik micrograms per - 2? - gra.ni of body weight as compared to 38 micrograms per gram of "body weight for DDT, when measured 120 hours after treatment. The corresponding values for LD-95 were approximately 25 micrograms per gram of "body weight for chlordane and 70 micrograms for DDT per gram of body weight. — Kearns et al . ( 2ij-5 ) . When chlordane was added to a urea-formaldehyde surface coating (50- percent on the dry weight), it was more effective than DDT hut less effective than gamma "benzene hexachloride a3 measured both by the time to cause 50 percent knockdown and the time to produce 100 percent knock- down.— Block Q£). See also under Blattella geriaanica . — Gahan §t al,. (l62) . The value of chlordane in controlling cockroaches has been demonstrated by pest-control operators and others. In general, practical tests have shown better results than those in the laboratory.— Knipling (26£)„ Chlordane has come into wide use against cockroaches. Its fumigating action plays a part in its effectiveness against cockroaches in hiding places.— Bishopp ( 32 ). The dairy of Oregon State College remained free of cockroaches for 6 months after the application of a kerosene-chlordane space spray.— Fowler (152). When tested in a dust chamber where a very small quantity of the test material was applied to a surface, a 5-percent chlordane dust killed all roaches in 3 days. — Lemmon ( 296 ) . Chlordane was recommended as one of the better insecticides for the control of roaches by the U. S. Bureau of Entomology and Plant Quarantine ( ^•72 ) in August 19*19 • Proper application of an insecticide is probably more important than the selection of the one to be used. Either powdered or liquid formulations will give satisfactory results. Gryllidae Gryllotaloa hexadactvla Perty, the American mole cricket Chlordane was applied to turf as a 5-percent dust at the rate of one pound of actural chlordane to the area and watered in. There was an average of nine dead mole crickets on each plot of 100 square feet. The effectiveness of chlordane against mole crickets persists for as long as six weeks to two months after application. Death results from ingestion, contact, and fumigation. — Kelsheimer ( 250 . 251 ). Acheta assimilis P., the field cricket A 5-percent chlordane dust applied at the rate of 1 pound of toxi- cant per acre reduced the population about 30 percent within 2M- hours. A - 28 - chlordane-bran "bait applied at the same rate reduced the population 50 percent. — Munro .si. al» ( 339 ) . Nemobius fasciatue Deg., crickets Crickets were more susceptible to chlordane than to DDT. A 0.05 per- cent chlordane dust killed 88.4 percent of crickets (nymphs and adults} in 2 days while a 1-percent technical grade DDT dust gave only 84.7 percent mortality. — Sun et al. ( 450 ). Scapteriscu , 8 a bbreviatus Scudd, the short winged mole-cricket Wheat bran bait containing 1-percent of chlordane killed 100 percent of these crickets in 10 days. A 50-percent chlordane wettable powder at 4 pounds per 100 gallons of water per 1000 square feet of surface was also effective.— Hay Blip ( 211 . 212). S capteriscus acletus E. & H. t the sourthern mole cricket .?_• vicinus Scudd., the Puerto Rican mole cricket, changa Chlordane kills much faster than does DDT. For seedbeds it is ad- vised to use 50-percent chlordane emulsion at the rate of 1/4 pint to 100 gallons of water, applying this solution by means of a sprinkling can to 1,000 square feet of seedbed area. One application should be sufficient to give protection for at least two to three weeks. Two pounds of 50- percent chlordane wettable powder mixed with 50 pounds of wheat bran makes an efficient poison bait. Application is made in the late after- noon or evening. The killing power seems to be increased by rains or artificial watering.— Kelsheimer ( 260-252 ). As little as 1/4 pound of chlordane as a 50-percent wettable powder in 100 gallons of water per 1000 square feet killed 95 percent of southern mole crickets in 8 day a. A 5-percent chlordane dust at 60 pounds per acre killed 95 percent in 10 days. The dust was mixed with commercial fertilizer and applied to the upper 2 inches of soil.— Hay slip (211, 2U) • Uniden tified crickets The University of Wisconsin ( 503 ) recommends chlordane for cricket control in the same dosage as used for grasshopper control. IS0PTERA Termitidae Tri ner vitoraes havilandi Fuller When applied as 2.5-percent kerosene sprays to various surfaces the initial toxicities of DDT, BHC, and chlordane are of the same order but - 29 - DDT is much mors persistent. BHC and chlordane become ineffective after 1 to 2 months, "but the toxic effect of DDT is appreciable after 10 months, None of the three was very effective upon enameled surfaces. BHC caused a quick knockdown hut if insects were then removed from treated surfaces, final mortality was often very low. Recovery after knockdown from DDT or chlordane v/as rare.-- Petty (.225.) * Rhino ter mi tid&e Reticu lltermes flavloes (Kollar), the eastern subterranean termite Chlordane mixed with sandy soil, 1 to 20,000, remained toxic for 3 years. — Hetrick ( 2 16) . Unidentified termites Soil treated with a 0. 25-percent emulsion of chlordane remained toxic to termites 13 months after application in a test at Urbana, Illinois.— Shelf ord (j&Z). A second test, made one year after the first test, showed that the soil had lost no toxicity. Furthermore, there was no difference between samples from a 3 inch and an 8 inch depth. — Shelf ord ( #L , 8 ) . THYSANOPTERA Thripidae Pranklinie3,la fusca, (Hinds), the tobacco thrips In small plot tests at Baton Rouge and Bossier City, Louisiana in 19^8, three applications of 10-percent chlordane dust at the rate of 10 pounds per acre at weekly intervals, beginning with the appearance of the first true leaf, gave satisfactory control. Although this treatment re- sulted in significant increases during the seedling stage in height and leaf surface of the treated plants as compared to the untreated checks, the differences were not reflected in yield between treated and untreated plants. — Newsom £t aJL» (.248) . Heliothrips haemor rho idal i s (Bouche), the greenhouse thrips In laboratory tests with adult female thrips chlordane was less toxic than DDT, gamma-BHC, TEPP, and parathion; about as toxic as toxaphenej and more toxic than TDE and methoxychlor. A concentration of 0.0035 percent gave a fifty percent kill.— Metcalf (322). Metcalf et al. (325). Scir t othrips citri (Moult.), the citrus thrips Chlordane was not promising in tests in southern California. — Ewart (i3Jt). - 30 - TaenlothrlT -- . c J._332lfii (*or.), the gladiolus thrips For thrips on gladiolus chlordane dust is more effective than DDT dust but not as effective as the Fprry. During March and Aorll when DDT sprays are not effective chlcrdane sprays give more satisfactory control especially where a severe infestation has developed. — Kagie ( 309 ) » An emulsion of 0.5 pound of chlordane per 100 gallons of water applied 6 times at weekly intervals at the rate cf 130 gallons per acre gave 94 percent clean flowers up tp.two weeks after *.he last application.— Smith (42.3); Smith and Boswell V&#J . A 5-percent chlordane dust and a 50-percent chlordane wet table pewder at 2 pounds per 100 gallons of water v/ere very effective in kill- ing thrips within the leaf folds and flower buds. — Magie and Kelsheiner Qlft). Good control of thripa on gladiolus was obtained from the use of 5 percent chlordane dust.— Jenkins (2J&) . Thrips , tabaci Lind., the onion thrips When tested on potted onion plants in the greenhouse, a dust mixture containing 2 percent chlordane gave excellent control of the onion thrips.— Sun e_t al . (k£Q) . In trials in Indiana in 19^6, 2- and 5-percent chlordane dusts and a 5-95 DDT-smfur mixture gave the greatest reduction in the thrips popula- tion.— Gould (186). A pyrophyllite dust containing 5 percent of chlordane, applied at the rate of 10,5 pounds per acre, caused a 98 percent reduction in the number of thrips 2U hours after treatment and a 71 percent reduction 5 days after treatment. These tests were made on seedling cotton at Bayview, Texas in the spring of 19^7 on 0.1 acre plots. — Fife ejfc al. (137). In 1947 in New Jersey, a 3-percent chlordane dust gave an outstand- ing reduction in thrips population and a fairly good increased yield of onions . — Pepper (.262) . Chlordane emulsion spray, 1 pound per 100 gallons of water, gave promising results in 19^7 in tests at Twin Falls, Idaho, causing a re- duction of 77 percent in the population. — Douglass and Shirck (1,3.2) . Chlordane, applied as a dust at weekly intervals, gave very good control of thrips on onions, reducing the number to an average of less than 9 per plant, whereas the untreated plants averaged 31 thrips per plant throughout the season. The plants in all treated plots were larger and greener than those in the check plots. — Floyd and Smith ( 1^6 ) . - 31 - ANOPLURA AND MALL0PHA.GA Chlordane has been tested against several species of sucking and biting lice and found to be highly effective, — Bushland (jiZ); Bishopp and Knipling Qjfc) . Tests with identified species have been reported a3 follows: Anoplura - Haematopinidae flaematopinus advent icius Neum., the hog louse In one test with a few animals chlordane wettable powder spray at 0.2 percent concentration gave apparent complete control of hog lice.— U. S. Bur. Ent. and Plant Q,uar. (468). Sprays containing 0.2 percent of DDT, TDE, or chlordane completely elimininated lice on hogs in tests made in Massachusetts in 1946. No irritation or harmful effects from the insecticides were observed. The chlordane acted most rapidly and the lice began to drop in a few minutes.— Sweetman ( 451 ) • Haemato-pinus eurysternus (Nitz.), the short-nosed cattle louse Linognathus vituli (L.), the long-nosed cattle louse A 0.5 percent chlordane suspension destroyed all short-nosed and long-nosed lice on heavily infested cattle in less than 8 hours, was non- irritating, and a single application was nontoxic to newborn calves. — U. S. Bur. Animal Ind. (465). Tests on cattle against sucking lice of the species Haemato-pinus eurysternus and on goats against biting lice, Bovicola spp., indicate that the motile forms are killed with lower concentrations of chlordane than are required for DDT. — Enipling (264). Linognathus , setosus (Olf.), the dog sucking louse No lice were found on dogs 24 hours after they had been dipped in a 0#42-percent technical chlordane emulsion. — Turk and Batte (46pj. Anoplura - Pediculidae Pedi cuius hvunanus corporis Deg., the body louse Chlordane was found to be outstanding against the body louse, but less persistent than DDT or toxaphene. — Bishopp Q2). When impregnated in cloth or when employed in powder form, chlordane proved much more effective than DDT. It also acted faster than DDT, paralyzing lice in 3 hours as compared with 6 hours for DDT. When compared - 32 - with DDT on the "basis of persistence, 1-percent and 5-percent powders of the two materials were about equal - perhaps chlordane was slightly more effective. In washing tests, garments impregnated with DDT were more re- sistant to loss of effectiveness than were those treated with chlordane. — Knipling (264). When applied to cloth and evaluated by the beaker test method, technical chlordane was effective at a concentration of 0.0005 percent. Lice exposed on cloths impregnated with 1 percent of insecticide were paralyzed within 3 hours by chlordane. Chlordane was about as long- lasting as DDT. Sleeves of cotton underwear cloth impregnated with 2 per- cent of the insecticides were compared for resistance to laundering. Toxaphene, which was the most effective treatment, remained lethal to lice after four 15-rainute boilings in a 1-percent soap solution. DDT lasted almost as long and was superior to chlordane. — Eddy and Bushland ( 126) . A single dose of chlordane was administered orally to rabbits at a dosage of 300 mg./kg. When undiluted chlordane in a gelatin capsule was fed to the animal, the mortality of lice feeding on the rabbit was l6 percent after 4 days. When administered as a 10 percent solution in corn oil (5 rag. /kg.) through a stomach tube, the mortality of lice was 60 percent after 2 days, but the rabbit died after 4 days. One rabbit receiving 300 mg. chlordane per kg. in corn oil died within 2 hours; another receiving 25 mg./kg. died within 3 hours. — Knipling .ai Sl» ( 266 ) Mallophaga - Menoponidae Eomenacanthus stramineus (Nitz.), the chicken body louse Menopon gallinae (L.), the shaft louse Mallophaga - Phil opt eridae G-oniocotes hologaster Eitz., the fluff louse Dusts containing 2 or 5 percent of chlordane, applied at rates from 2 to 10 pounds per 100 square feet of soil, gave excellent results and were somewhat superior to the 3-percent DDT dust. The birds remained free of lice for 4 to 5 weeks. — Creighton e_t al. ( 57 ) . One application of 5-p©rcent chlordane dust to the birds was less efficient than sodium fluoride, but gave satisfactory control up to 70 day 8 after treatment. Pens treated with 2-percent and 5-percent chlordane sprinkled over the litter at the rate of 2 pounds per 100 square feet were still free from lice 70 days after treatment. — Edgar ( 130) : Edgar e_t al. (131). In laboratory tests in Kentucky excellent control of body, shaft, and fluff lice was obtained with one application of 5-percent chlordane powder on the bird. — Ky. Agr. Expt. Sta. ( 2^3 ). - 33 - Cu , clotogaster heterographus (Nitz.), tlie chicken head louse Lioeurua caponis (L. ) , the wing louse Same as for Bomenacanthus s tramlneua . —Bdgar (1^0 ) ; Idgar ejt £■!• (121). Mallophaga - Trichodectidae Bovicola canrae (Gurlt), the red goat louse, the goat biting louse B. crassipes (Rud.), the yellow louse on goats Chlordane and DDT are about equal in efficiency against the red and yellow goat lice. In a limited number of tests a 0.2-percent concentra- tion of chlordane in dip form with either wettable powder or emulsion gave complete control which was maintained for at least k months. — U. S. Bur. Ent*. and Plant Quar. (*+68). £• eaul (!«•)» tlj » horse biting louse Chlordane emulsion was better than chlordane wettable powder, which was better than DDT wettable powder. The LD-50 of chlordane in emulsion form was 0.0^+3 percent. The sprays were applied to Shetland ponies by means of an electric hand sprayer. — Batte and Gaines (28) . Bovicola spp. See under Haematopinus eurysternus . — Knipling (26** ). HOMOPTERA Aleyrodidae Aleurocanthus wpglumi Ashby, the citrus blackfly The addition of 0.9 ounce of chlordane per gallon of light-medium emulsion oil which was applied as a 1.67-percent water emulsion did not enhance the toxicity of the oil to 1st, 2nd, and 3rd-instar larvae or to pupae. — Plummer and Shaw ( 3 , 68 ). Chlordane in Velsicol AE-60 or kerosene exhibited low toxicity. — Woglum evt a^. ( 506 ) . Trialeurodes vapor arior urn (Westw.), the greenhouse whitefly When applied as dusts containing 1 percent of the toxicant, chlor- dane was less toxic (52.6 percent mortality) than gamma-BHC (97.8) or aerosol grade DDT (85.6) to adults. — Sun et al. ( ^50 ). - y> - unidentified species A 5-percent chlordane dust applied for the control of the serpentine leaf miner on asters controlled whitefly, hut was inferior to a EHC dust (0.75 percent gamma content) for this purpose. — Jefferson and Pence ( 239 ) . Aphidae Anur aphis per sicae-niger (Smith), the "black peach aphid In Oregon a 2-percent chlordane dust killed only 18.5 percent of these aphids on peach trees. — Jones and Rosenstiel (244). Aphis gossypii Glov. t the cotton aphid, the melon aphid In lahoratory and cage tests at Waco, Texas in 1946, chlordane gave promising results against cotton aphids. — Harned ( 205 ) . At 10- and 20-percent concentrations chlordane dust was effective against cotton aphids, hut not quite so effective as corresponding con- centrations of toxaohene , or BHC (gamma isomer 5*75 percent). — Ivy and Swing (237). At Florence, South Carolina in 1947, 10- and 20-percent chlordane dusts gave good control of cotton aphid, hut a mixture of 10-percent chlordane and 5-percent DDT permitted a build-up of aphids in one test. — Eondy (41) . A 5-percent chlordane dust did not affect the aphid population. — Arant (20). At a dilution of 1 to 300 of an emulsion concentrate containing 20 grams of insecticide per 100 ml., chlordane was slightly less toxic than technical grade DDT to the melon aphid of various ages. — Sun e_t a^. ( 450 ) , In additional tests these workers ( 449 ) used the melon aphid as a test insect to evaluate different chlordane formulations. Chlordane 25-percent emulsion at 1:400 was unsatisfactory in con- trolling aphids (chiefly this species) on celery in Florida in 1948. Ho injury to celery plants was ohserved. — Wylie (514 ). Aphis fahae Scop. , the hean aphid Mixtures of nicotine and chlordane dusts tend to produce mortalities slightly exceeding those to he expected from similar joint action, hut the differences may not he great enough to prove synergistic action. At the 50-percent mortnlity level nicotine is 1.49 times as toxic as chlor- dane; at the 90-percent level nicotine is 1.43 times as toxic as chlor- dane. — Sun ( 445 ). - 35 - In the form of a 1-percent dust chlordane was more effective than aerosol grade DDT against the "bean aphid in greehou.se experiments in which aphids of various ages were included in the mortality counts. — Sun si fil* ( 450) . See under Epilachn a varivestis. — Huckett ( 229 ) . Anhls spiraecola Patch, the spirea aphid See under Macros iphum pisi . — Kearns e_t al. ( 245) » Macros iphum pisi (Kith.), the pea aphid In laboratory tests 10-percent chlordane was more toxic than 1-per- cent nicotine, and 2-percent chlordane was less toxic than 1-percent gamma-BHC . — B i shopp (^2 ) . In parallet tests with chlordane and DDT, applied as aqueous disper- sions to the spirea aphid and to the pea aphid, chlordane proved several times more toxic to these insects than DDT. The pea aphid is the less susceptible of the two species to "both compounds. — Kearns et, a2.. ( 245 .) » In laboratory tests 2-percent chlordane dust gave higher mortalities than aerosol grade DDT and toxaphene of the same concentration on adults of the pea aphid. In greenhouse and field experiments where aphids of various ages were included in the mortality counts, however, the results show that chlordane was less effective than technical grade DDT against the pea aphid. — Sun et al. ( 450 ) . A 5-percent chlordane high pressure aerosol gave 72 percent control of pea aphid in Virginia; DDT gave 94 percent control. — Anderson and Hof master (12) • Macroslphum solanifolil (Ashm. ), the potato aphid Tests made in Wisconsin in 1946 with tribasic copper sulfate plus insecticide showed chlordane both as a dust and as a spray to rank below HETP, DDT, nicotine, and BHC— Wis. Univ. (504 ). Same as for M. pisi .— Sun et al . ( 4,50 ). Myzus per sicae (Sulz.), the green peach aphid For the control of the green peach aphid on shade grown tobacco in Florida in 1947, chlordane at first gave an excellent kill, but later applications (perhaps of a different compounding) did not prove effec- tive.— Wilson el al. (499). In greenhouse experiments a 1-percent chlordane dust was more effective than a 1-percent technical grade DDT dust. — Sun et al. ( 450 ) . - 36 - In Florida chlordane ^O-percent emulsion at 1:^00 showed promise, but was less effective than BHC, parathion, and DDT emulsion in combat- ing these aphids on cabbages. — Kayslip ( 2ll ) . Phyllanhis f aercent mortality in 2k hours, 59 ~<>rcent in kQ hours and 100 percent in 1^4- days. In the plot treated with chlordane no retardation in the new growth or vigor was noted. — Eastings and Peur>er (205). Protostronhus sp., ground weevils Laboratory tests showed that 5-percent chlordane dust at the rate of 0.11 mg./sq. cm. (10 pounds per acre) caused ltSO percent mortality in ?2 hours. — Petty (3q3.) . Pseudocneorhinus bifasciatus Hoelofs, a Japanese weevil Preliminary tests indicated that chlordane was likely to prove more effective than 3HC, DDT, or arsenate of lead in controlling this weevil feeding on privet. — Allen (13) . Sitcna scissifrons Say « In North Dakota in 19^7 2-percent chlordane dust proved inferior to 5- percent DDT dust in controlling this weevil on peas. — Post et_ al. ( 371 ) . Sitophilus granarius (L.), the granary weevil In laboratory tests in which the insecticide was dissolved in oil and this solution allowed to spread on filter paper and age 2k hours "before placing the weevils on it, chlordane proved less toxic than DDT. The rela- tive potencies of chlordane with respect to DDT at 95, 50, and 25 percent kill are 0.19, 0.50, and 0.7**-. — Stringer (kkk) . The adults of this weevil proved suitable as test insects for the "bioassay of the content of chlordane in ^reparations of this toxicant. The method consists of exposing the weevils to deposits of the preparation and of the pure insecticide that it contains and comparing the median lethal deposits. — Krijgsman and Berger ( 26S ) . See under Musca domestica. — Brown e_t r^l . (^2_) . Trichobaris mucorea (Lee), the tobacco stalk borer A 5-percent chlordane dust was more effective than a 10-vercent DDT dust in -oreventing egg laying 3 weeks after the last application. A chlor- dane spray (2 pounds of 50-percent wet table powder per 100 gallons of ber) war, less effective than EHC, but more effective than DDT and toxa- phene in preventing egg laying. Chlordane was slower than BHC in killing the beetles caged with freshly sprayed foliage. — V'oodside (ill.). Ty I oderma f r .- , -nx iae (kiley), the strawberry crown borer Five percent chlordane dust killed 100 percent of the adults in labora- tory tests and gave excellent res-alts in field trials. — Kitcher ( 396 ) . - 49 ~ Dasytidae Astylus atromaculatus Bl., the Astylus "beetle In laboratory tests 5-percent chlordane dust killed all "beetles In 72 hours when applied at the rate of 0.11 mg./sq. cm, (10 pounds per acre). — Petty (363). Dermestidae Attagenus piceus (Oliv.), the "black carpet "beetle Woolen cloths impregnated with six chlorinated hydrocarbon insecticides at concentrations ranging from 0.5 to 3 percent by weight of cloth were ex- posed to larvae of the black carpet beetle for 28 days. The following mortalities were obtained: chlordane 75 to 100 percent; benzene hexachloride (6 percent gamma) to 100 percent; toxaphene 25 to 52 percent; DDT 15 to 4? percent; TDE 3 to 14 percent; and methoxychlor 1 to 6 percent. According to the visual damage and frass weight noted during these tests, the greatest protection to woolen cloth was obtained with DDT, TDE, chlordane, methoxy- chlor, toxaphene, and benzene hexachloride in the order named. Washing and dry cleaning seriously affected the toxicity and the protective value of all the treated cloths, with the exception of those treated with DDT, which re- sisted one washing at all concentrations. — Laudani and Marzke ( 285 ) . Elateridae Aeolus spp. , wireworms The results from one experiment made in Louisiana in 1947 indicate that most of the wireworm injury to fall-planted cane may be prevented by apply- ing 400 pounds of dust containing 1 percent of chlordane per acre in the furrow with the seed cane at the time it is planted. — Bynum et al. (63) . Agriotes mancus (Say), the wheat wireworms Chlordane gave good control at 2 to 4 pounds per acre where wireworm infestations were light but under heavy infestations 4 to 8 pounds were required. — Rawlins et ajl . ( 386 ) . Seed corn was treated with chlordane at the rates of 4 and 8 ounces of 50-percent dust per bushel. This treatment did not affect the germina- tion, but proved ineffective against wireworms in both laboratory and field tests. Both field plots were severely injured. — Dogger and Lilly ( 1,0,9.) . Conoderus vesper tinus (E.), the tobacco wirewor m Chlordane was mixed with screened soil, broadcast on the plots, and disked into the soil 3 weeks before the tobacco plants were set out. Where chlordane at 2.5 pounds per acre was used, 55*7 percent fewer plants were injured than in the untreated plots; at 3«5 pounds per acre 70.5 percent fewer plants were injured. BHC was more effective. — Ky. Agr . Expt. Sta. (218)/ - 50 - VThere damage from this insect is expected, add chlordane to trans- planting water at the rate of 1/2 pound of 50-percent wettable chlordane powder to each 50 gallons of water. Use liberal amounts of water as as to wet the soil all the way to the top of the ridge around plants. — Settles and Lewis (3W: Kulash (2?6). Conoderus spp. Sane as for Ae_ol_u§ spp. — Bynum e_t a^,. (63) . Dalot)iu3 pallidus 3rown Sane as for Agxiote s inancus . — Dogger and Lilly ( 109 ,) . Drasterl.u s iqellillus (Say) Sane as for Agriotes jnaacJlSj — -Dogger and Lilly ( 109) . Horistonotus uhlerli Horn. , the sand wireworm Chlordane, 2.5 pounds per acre, proved highly effective in the control of the sand wireworm in large plot tests in 19*^8 in Louisiana. — Floyd ( 1^3) . Chlordane nay "be mixed and applied with fertilizer or sand in the row at slanting time or broadcast over the field in the fall. — Floyd and Snith (143). Limoniua ectypus (Say) In Ontario in 19^7 chlordane at 0.25 pound per acre was inferior to the sane dosage of BHC. Chlordane was not promising in protecting t potatoes hut gave an increased yield of corn. — Arraand (2J+) . A ijO-percent chlordane wettahle powder at 2 pounds per 100 pounds of sugar beet seeds caused 2/3 of the larvae to "be moribund and 1/3 dead in 6 weeks. In another test 1 percent of 50-percent chlordane wettable powder (based on weight of sugar beet seed) gave poor control. Of all chemicals tested lindane was the most promising. — Lange at a^. ( 282 .) . Limonius mancus (Say) Same as for A/riotes m ancus . — Rawlins §t_ al. ( 386 ) . Helanotus communis Gyll. t the corn wireworm Same as for Aftrlotee mancus . — Dogger and Lilly ( 109 ) . Melanotus spp. Same as for Aeolus spp. — Bynum e_t ai,. (63) . - 51 - Unidentified wireworms Chlordane was tested against wireworms in lima bean fields in Orange County, California. It was applied April 20, 19^7. at the rate of 10 pounds per acre and the beans were planted 10 days later. In August all treated plots were better looking than the untreated plots. Ethylene dibromide gave the best control against wireworms and nematodes of all materials tested (DDT, benzene hexachloride, chlordane, and ethylene dibromide).— Crosby (82). In preliminary tests in California chlordane proved effective for the control of wireworms when used at the rate of 10 pounds of technical grade chlordane in 20 gallons of solvent (such as benzene) per acre. The material was drilled into the soil to a depth of 6 inches using 12 inch spacings in the same manner as ethylene dibromide. — Lange ( 2§i) • In Connecticut in 19^7 chlordane applied as a wettable powder by the conventional potato sprayer resulted in excellent tobacco stands at 5 and 2 1/2 pounds per acre even in cases in which more than half of the plants in comparable control plots were down. There was no off-taste or impaired burning quality of cured tobacco leaves secured from these plots. Chlor- dane produced an off-flavor in potatoes but to a much milder degree than BHC. — Greenwood ( 195 ): Turner (k6l), Chlordane was inferior to parathion and benzene hexachloride in con- trolling vireworms attacking newly planted sugarcane in Florida. When chlordane was mixed with fertilizer and applied immediately, good control was obtained. —Hayslip ( 210 . 211). Chlordane offers some promise in wireworm confc*ol. Apply as a dilute dust to the soil surface and then disc or harrow into the top four to six inches of the soil. Five pounds of chlordane is the usual dosage. — Kulash (276) . Meloidae Decapotoma lunata Pall., C.M.E. beetles In laboratory tests 5-percent chlordane dust killed all beetles in Zhe hours when applied at the rate of 0.22 mg./sqL. cm. (20 pounds per acre). —Petty (363). Eoicauta pennsylvanica (Deg.), the black blister beetle In Indiana in 1946 chlordane proved ineffective against the black blister beetle . —Could (186) . - 52 - Scarabaeidae Amnhimallon na .jails (Eaz.), the European chafe? A mixture containing 15 percent of chlordane, 82.5 percent cf ethylene dichloride and 2.5 percent "Tween 20" diluted with water, 5 to 20 ml. per gallon per square yard of soil, gave from 12.2 to 21.9 percent control of third-instar larvae of the European chafer three weeks after treatment of the soil plots. — Gambrell and Mason ( 171 ) . Anomala oriental is '.faterh., the oriental "beetle Autoserica castanea (Arrow) , the Asiatic garden "beetle Practical control of the oriental beetle was obtained with chlordane at 5»^ and 10.8 pounds to the acre and a mixture of DDT at 13 pounds, an chlordane at 5»^ pounds to the acre. In another test a 50-percent chlor- dane powder, applied dry with a patented turf duster, in April, at a rate to give 10 pounds of toxicant to the acre on a mixed population, gave full control of the new generation, which consisted largely of oriental beetle larvae, by October.— Adams (£) . Conostethus impressua ( G-oldf . ) In laboratory tests 5-percent chlordane dust killed only 6.6 to l6.6 percent of the beetles in 120 hours when applied at the rate of 0.22 mg./ sq. cm. (20 pounds per acre) . — Petty ( 363 ) . Cotinis nit Ida (L . ) , the green June beetle Chlordane at 3 1/2 pounds per acre, worked into the soil to a depth of 3 inches, killed 26.5 percent of the grubs and at 5 pounds per acre it killed 38.9 percent of the grubs. A 5-percent chlordane dust and chlor- dane spray were ineffective against the adults in laboratory tests. — Xy. Agr. Expt. Sta. (258). Cyclocephala boreal is Arrow, the northern masked chafer A 5-percent chlordane powder, applied to soil with a fertilizer spreader at rates of 5»*+ to 21.7 pounds toxicant per acre, virtuall;- elimi- nated all grubs on a golf course on Long Island. The chlordane was applied in May and observations made in October. — Adams (8). Popillia japonica Newm. , the Japanese beetle Chlordane is very effective against Japanese beetle larvae ts. The principal tests of chlordane against this beetle have been made in I Jersey by Fleming (122, ljjO) , in Connecticut by Schread (^ 05-410 ) . and in Maryland by Langford and Squires ( 284 ) . In laboratory tests of treated soil against third-instar larvae 1 pound of chlordane per acre when freshly applied was as effective as - 53 - pounds of DDT. At the end of 8 weeks in the soil 2 pounds of chlordane were required to equal 25 pounds of DDT. In field tests 10 pounds of technical chlordane per acre reduced the larval population more rapidly and more completely than did DDT at 25 pounds per acre. In these tests the chlordane was applied as a 5-percent dust to the surface "by means of a 3- foot fertilizer spreader. — Fleming (122.). All stages of the Japanese "beetle in soil are killed "by dipping "balled or potted plants in an emulsion prepared "by adding 1 fluid ounce of the following solution to 10 gallons of water: Percent "by weight Ethylene dihromide 13.0 Chlordane (technical) 6.5 Cellosolve (ethylene glycol monoethyl ether) 6.5 Tveen 20 6.5 Isopropyl alcohol 67 .5 — Chisholm ai*l Mason (26); Mason and Chisholm Ql8). Japanese "beetle adults may "be controlled "by a 50-percent chlordane wettahle powder used at the rate of 2 teaspoons to a gallon of water and applied to vegetation at weekly intervals during July and August. This dosage of chlordane is 1/2 that recommended for DDT. — Schread ( 405 ). Chlordane as an emulsion was not as effective as DDT or "benzene hexa- chloride from the standpoint of either knockdown or residual effect. — Langford and Squires ( 284 ) . Aldrin proved more toxic than chlordane against Japanese "beetle grubs; 6 pounds of aldrin in 10 days gave greater grub reduction than 10 pounds of chlordane in two weeks. — Schread ( 4-10 ) . In tests made in Connecticut in 1946, 19^7, and 1948 chlordane at 8 pounds per acre was effective against Japanese "beetles at the end of 18 months. — Schread ( 409 ). In 1949 the U. S. Bureau of Entomology and Plant Quarantine (462, 470 ) recommended chlordane for grub control where quick action is needed. Chlor- dane kills the grubs faster than either DDT or lead arsenate. Use 10 pounds of actual chlordane per acre in a dust or spray. A chlordane treatment should last at least 2 years. Adams and Matthysse (£) of Cornell University recommend chlordane at the rate of 10 pounds per acre for the control of Japanese "beetle gruos. Chlordane acts more rapidly than DDT, killing grubs in from 2 to 3 weeks after application. Indications are that its effectiveness will persist for a least 2 years. - 54- Scolytidae Hylastinus obscurus (Marsh.), the clover root boier A 5-percent chlordane dust, applied at the rate of 2.5 pounds of toxi- cant per acre in May 1947 in Hew York, rave excellent control and a 1-per- cent chlordane dust at 2.25 pounds of toxicant per acre gave high control. Uone of the insecticides tested as sprays at the rate of 1 pound of toxi- cant oer acre were satisfactory. Chlordane did not injury red clover. — Marshall et al. (314). Chlordane dust at the rate of 2 pounds toxicant per acre gave 46.6 percent non-infested plants as compared to 30 percent in the untreated check. The clover hay at harvest time "bore a chlordane residue of 2 p.o.m. Aldrin, dieldrin, and BHC gave the "best (90 percent or "better) controls. — Gyrisco and Marshall ( 199 ). Tenehrionidae Tribolium castaneum (Host.), the red flour "beetle Portions of insecticidal dusts, judged to "be "between 50 and 100 mg., were applied to counted groups of T. castaneum in 2x1 in. specimen tubes. The tubes were gently shaken to distribute the dust and were then stored under controlled conditions of temperature and humidity until the insects were inspected. The results show that a relatively small increase in con- centration of poison in a dust results in a large increase in mortality. Frequently, a fourfold increase in concentration has resulted in a change from a very low to very high mortality. A 0.1 percent chlordane dust killed 99 percent of the beetles in 24 hours at a temperature of 75° F. and a relative humidity of 70 percent. Chlordane was about 5 times more toxic than toxaphene. — Lord ( 3 , . 2 ) . Tribolium confusum Duv., the confused flour beetle Larvae are more resistant than the adults to spray residues. Eg's and pupae of the confused flour beetle do not appear to be materially affected by exposure on surfaces that have been sprayed with residual sprays. Immature stages were exposed for 24 hours to deposits of DDT, chlor- dane, and gamma benzene hexachloride that had been applied to glass plates at the rate of 50 mg. per 1/4 square foot. Eggs hatched almost normally, the average percentage being 77 after exposure to DDT, 75 for chlordane, and 47 for gamna benzene hexachloride, as compared with 77 percent for ' check. A residue of 200 mg. chlordane per square foot on a glass plate killed 100 percent of the adult beetles ej.rosed to it for 24 hours in 18 days. The effectiveness of residual sprays decreased with the increase in the absorptiveness of the surface sprayed. Their effectiveness also rarle vrith the chemical composition of tke surface. On cement surfaces the dur.. tion of effectiveness of all spray deposits was very short. Pretreatr.ent of cement with a sealer, magnesium-zinc-silicofluoride , ^d - 55 - the efficiency of spray deposits. On freshly painted wood surfaces the type of finish influenced the effectiveness of the spray deposit. Cold- water and flat oil paint greatly reduced the effectiveness of the spray deposits "but enamel did not. Water suspensions of wettable powders were absorbed less than other formulations, so that on absorptive surfaces, such as cement and cardboard and unpainted v/ood surfaces, they were more effective. — Cotton and Frankenfeld (8l); Cotton et, al. (83) . Chlordane formulated as an emulsion was sprayed on variously treated wood surfaces and flour beetles were exposed to the residues (200 rcg. chlordane per square foot) for 6 hours. The mortality of the beetles 12 days after exposure was 100 percent on the unpainted surface, 30 percent on cold-water paint, 20 percent on flat oil paint, and 60 percent on enamel. — Cotton and Frankenfeld (82) . See under Musca domestica . — Brown et, al. (52) . See under Blattella germanica . — Brown, Wenner, and Park (53). LEPID0PTERA Aegeriidae Melittia cucurbitae (Harr.), the squash borer In experiments at Geneva, New York, control of the borer was obtained with a 5-percent chlordane dust. — Csrruth and Eowe (66). Sanninoidea exitiosa (Say) , the peach tree borer In tests made in Virginia in 19^7 and 19^8 chlordane at 1 pound per 100 gallons of water was not so effective as DDT and had a relatively short period of residual killing. — Bcbb Q2) . Crambidae Diatraea sac char al is (P.), the sugar cane bbrer In Louisiana in 19^-6 poor control (51 percent) of the borer was obtained with a 5 percent dust of technical chlordane. — Ingram et. al. ( 236 ) . In ly47 chlordane accounted for a significant increase in borer infes- tation following second generation dusting, due apparently to its injurious effect upon the natural enemies of this pest. At one location in Louisiana chlordane caused a loss in yield of 6.65 tons of cane per acre. — Dugas e_t al. (117). - 56 - Lymantriidae Fu proctiE termir.alis (Walk.), the pine brown tail moth In laboratory tests a 5-percent chlordane dust applied at the rate of 10 and 15 pounds per acre was less effective than DDT, toxaphene, and lead arsenate. — Petty ( 3o3 ) . Olethreutidae Carpocapsa pomonella (L.), the codling moth In Illinois in 19^6 one pound of chlordane per 100 gallons of water, either as a 50-pe r cent wettable powder or as an emulsion, proved less ef- fective than lead arsenate or DDT in controlling codling moth on apples. — V.'einnan ( ^466 ) . An emulsion of chlordane (150 g. chlordane and $00 g. white oil in 100 liters of water) was almost as good as DDT (88 percent efficacy as com- pared to 95 for DDT) in the control of codling moth larvae on apples in France in 19^7. There was no phytotoxic action. — Frezal (15?,) • Chlordane, 2 quarts of 20-percent concentrate in 100 gallons of water, proved less effective than lead arsenate against the codling moth in Virginia.— Hough and Hill (227). In Indiana Steiner e_t al.. ( U38 )ln 19^+8 reported that chlordane has proved of little value for use in control of the codling moth or other apple insects. In tests to control the codling moth attacking Payne walnuts in northern California chlordane was found not only to "be ineffective, hut its use resulted in a marked increase in the codling moth infestation, which exceeded that which occurred in the unsprayed trees. One spray of chlordane, 0.5 pound per 100 gallons of water in 19^6, resulted in 1^ per- cent of the nuts being infested as compared to 7.05 percent infested in the check.— Michelbacher and Middlekauff (327). Grapholitha mplesta (Busck), the oriental fruit moth Field tests on peaches in New Jersey showed chlordane to be inferior to parathion when applied as sprayw for the control of second and third brood oriental fruit moth. — Driggers and "errill (HJi) . In Virginia in 19^7 chlordane was not effective in killing oriental fruit moth adults. Spray residues of the insecticide, however, were ex- trenely toxic to Macrocentrus parasites and residual killing was noted for several weeks after application under favorable conditions. — Bcb'r ( 33) . Injury by third brood moths reached outbreak proportions in peach orchards in Kentucky where chlordane had been used. Bacterium pruni seriously affected 17.1 percent of the fruits in chlordane sprnyed plots, - 57 - and only 3.2 percent of the fruits in plots sprayed with the standard lead arsenate schedule. — Ky. Agr. Expt. Sta. ( 258 ) . Polychrosis botrana (Schiff.) In France in 19^7 chlordane was tested as an emulsion (150 g. chlor- dane, 500 cc. petrole, 10 g. emulsifier and 100 liters of water). Its efficacy according to Abbott's formula was 80 as compared to 85.9 for DDT.- Erezal (157). Polychrosis viteana (Clem.), the grape "berry moth In tests made in the Erie grape "belt of Pennsylvania a spray of chlor- dane (as a 50-percent wettable powder) at 0.75 pound of toxicant per 100 gallons of water was not effective and severely "burned the foliage of the Concord grape. — Cox ( 8^ ) . Phalaenidae Phalaeninae In tests made at Charleston, South Carolina a 5-percent chlordane dust, applied at the rate of 20-25 pounds per acre-application, was fairly toxic to the cabbage looper and Agrotinae, "but relatively ineffective against the imported cabbageworm in two spring tests and one fall test. A 3-per- cent chlordane dust was not very toxic to either the looper or the imported cabbageworm in two spring experiments. A chlordane suspension spray and an emulsion spray gave good to excellent reductions of the looper and im- ported cabbageworm and were superior to a 3-percent chlordane dust when applied at comparable dosages of active ingredient. This dust mixture did not have good dusting qualities. Chlordane dusts usually proved inferior to DDT dusts of comparable strengths. No plant injury was noted from the use of chlordane on cabbage. — Re id and Cuthbert ( 387 ) » Agrotjs orthofronla Morr., the pale western cutworm Chlordane dissolved in benzene-kerosene mixture and applied in a spray tower was moderately toxic to the larvae. — Brown et. al. (50) . Agrotis ypsilon (Rott.), the black cutworm A bait containing 1.5 percent of chlordane, 5 percent of xylene, and 11 percent of oil in bran killed 67 percent of the cutworms after *+8 hours in laboratory tests. — Brooks and Anderson (i±8) . A 5-percent chlordane dust, applied to fields in North Carolina at rates of from 20 to 100 pounds per acre, was of little value. Irish potatoes grown in chlordane-treated soil showed no of f -flavor . — Kulash (228). STATE. .»S5SW® - 53 - Anticarsia g-eismatllls &bn.). the velvetbean caterpillar A low concentration of chlordane showed some premise for the control of this insect in Louisiana in 1946, but the next year it gave very little control after five day 6. — Dugas j»t a^.. ( ll6 t 118 ) . A 1-percant chlordane dust was less effective than 1-percent DDT and 1-percent ganma benzene hexachloride dusts in controlling caterpillars on alfalfa in Alabama in 1946. All dusts were applied at the rate of 15 pounds per acre. In 1947, 5-percent chlordane dust gave 68 percent control of the larvae on soybeans 48 hours after dusting at the rate of 25 pounds per acre.— Arant (21) . Cjrphis unipuncta (Haw.), the armyworm In preliminary laboratory tests chlordane was much less toxic than DDT.-- Bishopp Q2). Rellothis armigera (Hbn. ) , the tomato frultworm, the bollworm, the corn earworm A field test on tomatoes made in Louisiana in 1946 showed 2-percent chlordane dust to be inferior to cryolite and calcium arsenate. — Floyd A 5-psrcent chlordane dust gave controls of 41.6 and 38.7 percent in two tests on western Long Island in 1948. The effectiveness of chlordane was less than that of DDT, TDE, parathion, or methoxychlor . — Butler and Carruth (&) . Dusts containing 5» 10 • and 20 percent of chlordane failed to give adequate control of the bollworm. — Arant (20) ; Kulash ( 27^ ) • In laboratory and cage teats in Texas a 20-percent chlordane dust was less effective against the bollworm than DDT or toxaphene. — Ivy and Eving (2^2). In Texas diu-ing 1947 a 20-percent chlordane dust was as effective as calcium arsenate, but less effective than a 20-percent toxaphene dust ox a 5-percent DDT plus 3-percent gamma benzene hexachloride sulfur dust in controlling bollworm. — Gaines and Dean (l6ii) • An emulsion of chlordane atomized on corn ears showed promise against the corn earworm. — Bishopp (32). In Horth Carolina in 1947 a 5-percent chlordane dust gave 40.4 per- cent clean ears as compared to 75*5 percent clean ears resulting from the use of 0.25 percent DDT in mineral oil. Of the untreated ears 27.0 per- cent were clean. — Kulash (273,) « In Florida in 1947 a 5-percent chlordane dust and a 50-p«rcent chlor- dane wet table powder at 2 pounds per 100 gallons of water were inferior to DDT and methoxychlor dust and sprays in controlling earworms on sweetcorn.— Kelsheimer (249). - 59 - In the Everglades area of Florida a 3~percent chlordane dust gave 6 percent of ears with no worm damage; a 5-percent DDT dust gave 39 percent; and 2.7-percent DDT in oil gave 100 percent. A 40-percent chlordane emulsion, 1 quart to 100 gallons of water, was about equal to DDT emulsion, "but less effective than parathion (2 pounds of 15 percent wettable per 100 gallons of water) in preventing tomato injury by the tomato fruitworm. — Hay slip (211). In laboratory tests 5 percent chlordane was slightly less toxic than DDT, natural cryolite, or 2 percent parathion. — Petty ( 3 63 ). A 1-percent solution of chlordane in refined mineral oil (Saybolt viscosity 185-195 sec. at 100° F.) injected into tips of ears of Golden Cross Bantam sweet corn in southern California was slightly less effective than 1-percent DDT and TDE solutions. These materials all gave good con- trol when applied as high pressure aerosols. — Anderson and Hashe (18). In Louisiana, in 1948 chlordane dust, applied 8 times at an average dosage of 12 pounds of dust per acre per application, failed to control insects on Mexican June corn planted August 13. The plants were more than 50 percent destroyed and no ears were produced. — Floyd ( l44 )» A 5-percent chlordane dust gave less than 50 percent worm-free ears in tests with sweet corn in North Carolina. Cotton treated with 5 percent chlordane was as heavily infested with bollworms as untreated cotton. — N. C. Agr. Expt. Sta. (353). In the Lower Eio Grande Valley of Texas a 5-percent chlordane dust (4 dustings at weekly intervals) gave 4-5 percent earworm injury as com- pared to 79 in the untreated plants. A spray of 4 pounds 50-percent wet- table chlordane per 100 gallons of water gave 2-percent whorls with live larvae compared to 45-percent in the untreated. — tfene and Blanchard (4. 9 , 5 ) » Heliothis ononis (Schiff), the flax bollworxn Chlordane dissolved in benzene-kerosene mixture and applied in a spray tower had very slight effect on the larvae. — Brown jgt ai. (50). LaT>hygma frugiperda (J. E. Smith), the fall armyworm A 5"*percent chlordane-pyrophyllite dust, applied 3 times to a total of 28 1/4 pounds per acre, gave a control of 98 percent of armyworms after 72 hours. A bait containing 1.5 percent of chlordane, 5 percent of xylene, and 11 percent of oil in bran killed 100 percent of the armyworms after 24 hours in cage tests, and 93 percent after 48 hours in field tests. Chlor- dane dust failed to control late fourth-instar larvae. — Brooks and Anderson (48) . In tests made on field corn at Norfolk, Virginia, in July 1948, a 3-percent chlordane dust reduced the number of worms 57 percent below the check in 24 hours and increased the percentage of uninfested plants above - 60 - the check 46 percent in 24 hours and 6l percent in 48 hears. In another test in a pasture a 5-percent chlordane dust killed 62 percent of the army- worms. Parathion and DDT gave the test control. — Hof master and Greenwood (225). Fire percent chlordane dust was fairly effective in controlling the armyworm but affected the corn adversely. — Tissot and Kuitert ( 456 ) . Chlordane dust was effective against this insect on tomatoes in Florida. — Kelsheimer (248). For the control of this insect attacking lawns in Florida it is recommended to use 2 pounds of 50-percent chlordane wettable powder per 100 gallons of water per acre or a 5-P©rcent chlordane dust.- Kelsheiaer Chlordane, applied as an emulsion to corn ears, imparted an odor noticeable at harvest time. Dusts gave unsatisfactory control, but chlor- sLase emulsion (l ml. plus 0.5 ml. of emulsifier, 20 ml. of white mineral oil and water to make 100 ml.) gave consistently good control of this species and the corn earworm in sweetcorn. — Blanchard and Chamberlin (35) . Chlordane wettable powder (50-percent) at 2 pounds per 100 gallons of water gave good control of fall armyworms in the buds of corn. A poisoned wheat bran containing 5 percent of chlordane also gave good con- trol.— Hayelip ( 210 . 211 ). A 5-percent chlordane dust, applied at the rate of 10 pounds per acre to Ladino clover, killed 1/2 the larvae two days after dusting. No phyto- toxicity was observed. — Kulash ( 274 ). See also under "Unidentified ants" . — Kelsheimer ( 252 ). Perldroma margaritosa (Haw.), the variegated cutworm In preliminary laboratory tests chlordane was much less toxic than DDT.— Bishopp Q2) . Platysenta sutor (On.) A 5-percent chlordane dust killed 24.2 percent of the larvae on celery in Florida in 24 hours.— Hay slip (211). Prpdenia er ldania, (Cram.), the southern armyworm In laboratory tests a 1-percent chlordane dust killed 96.? percent of medium larvae in 2 days. — Sun e_t aj,. ( 449 . 450 ) . In fumigation action against larvae chlordane was superior to gamma- BHC and DDT, "but in contact action and stomach action it wa6 inferior. — Sun e_l ai. (448). - 61 - Prodenla litura (*.) On fourth-instar larvae chlordane was almost as toxic as was DDT (83.3 percent mortality as compared to 95 percent for DDT after 46 hours).— Prezal (152). Trichoplusia ni (Hbn.), the cabbage looper In field tests a 3-percent chlordane dust killed 62.6 percent of the larvae in 3 days, and a dust containing 1 percent chlordane plus 0.25 per- cent rotenone 52.7 percent. — Sun ejfc ai.. ( 450 ). In laboratory and cage tests at Waco, Texas, during 1946 a 20-percent chlordane dust was less effective than toxaphene. — Ivy and Ewing ( 237 ). Same as for Plerls ranae . — Dills and Odland ( 105 ). Unidentified species of cutworms When fields of grain, grass, or alfalfa were sprayed or dusted with 3/4 or 1 pound of chlordane per acre, many species of cutworms were killed.— Severin (414) . To control cutworms in a prepared seedbed apply about 30 to 40 pounds of 5-p©rcent chlordane dust per acre. — Granovsky ( 194 ) . Older cutworms are not controlled by chlordane .— U. S. Dept. Agr. Ext. Serv. (473 ). Chlordane dust is recommended for control of cutworms attacking sweet- corn in Florida. — Kelsheimer ejt aj,,. ( 266 ). Pier idae Goliae philodlce eurytheme Bdv., the alfalfa caterpillar A 5-percent chlordane dust at the rate of 1.25 pounds of toxicant per acre reduced the number of caterpillars 52.8 percent in 48 hours and 65.3 percent in 96 hours. — Smith and Allen (427 ). Pleris rapaff (L.), the imported cabbage worm In 1946-19^*8 a 3-percent chlordane dust gave 72.6 percent control, proving inferior to DDT .and TDE.— Dills and Odland ( 105 . 107). In a field test chlordane dust proved superior to benzene hexachloride, Brooks and Anderson (48) . In laboratory tests a 3-percent chlordane dust killed only 5»6 percent of last instar larvae in 2 days as compared to 79.2 percent killed by a 3- percent technical DDT dust. In field tests a 3-percent chlordane dust - 62 - killed 59*4 percent of the larvae in 3 days; a 3-percent DDT dust killed 79^5 percent; and dust containing 1 percent chlordane plus 0.25 percent rotenone killed 85.1 percent. — Sun et a!. (45QJ . Psychidae Acanthppsyche J , un.odj Heyl , the wattle bagworm In laboratory tests a 5~percent dust of chlordane, applied at the rate of 5, 7, 9 t and 10 pounds per acre, was markedly more effective than natural cryolite against first and second instar bagworms when applied to the leaves only or when "both leavee and worms were dusted. Chlordane ap- peared to he slightly less effective than "benzene hexachleride against the first two inatars, and was less effective than cryolite for the older hag- worms.— Petty (364). Phycitidae Acrobagla carvaj Grote, the pecan nut case bearer Chlordane 44-percent emulsion concentrate at 1 quart per 100 gallons of water, applied late in the summer, Central Texas, in 1947, was less ef- fective than DDT or lead arsenate in preventing nut oasebearers from going into winter quarter*. — Nickels ( 35l ). Elaemophalpus lignosellus (Zell.), the lesser cornstalk borer In Louisiana chlordane at the rate of 2.5 pounds per acre proved much more effective than 10 pounds of DDT and produced a nearly perfect stand. — Dugas a! aL. (120). gphestja kuehniella Zell., the Mediterranean flour moth See under Mu,sca domestica . — Brown e_£. ai.. (52) . Homalopalpia dalera Dyar, the papaya webworm A spray of 0.05 percent chlordane reduced the percentage of webs with larvae to 14.4 as compared with 8l.7 in the check 7 days after treatment, but 36 days after treatment the percentages were 30.4 and 44.6, respec- tively. — Wolfenbarger ( 507 ). Pyraustidae De.spiia, funeral is (Hbsn.), the grape leaf folder In California in 1947 a dust, containing 5 percent of chlordane and 50 percent of sulfur, was less effective (9 and 27.4 larvae in rolls per - 63 - vine in two tests) than a 50-percent cryolite, 5-psrcent DDT, and ^0-per- cent sulfur dust (1.6 and 2.4 larvae in rolls per vine). The untreated check vines contained 35.8 larvae in rolls -per vine. — Frazier and Barnes (15&). Loxostege similalis (Guen.), the garden webworm In "barrier and dusting tests a 5-psrcent chlordane dust gave the most promising results. — Walton ( 48.3 ). In laboratory and cage tests at Waco, Texas during 1946 a 20-percent chlordane dust was less toxic than toxaphene, "but the results were con- sidered promising. — Ivy and Ewing (237 ). See *ader "Unidentified ants" .— Kel she imer (252). Phlvctaen ia rubigalis (Guen.), the celery leaf tier In preliminary laboratory tests chlordane was much less toxic than DDT.— Bishopp (221. Pyrausta nubilalis (Hbn.), the European corn "borer Chlordane dust was promising in tests made in Maine but was not so effective as DDT and Eyania. — Hawkins and Thurston (209 ). Chlordane spray gave excellent control in Ontario in 1947* — Wreasel . Sphingidae Protoparce quinquemaculata (Haw. ) , the tomato hornworm P. sexta (Johan.), the tobacco hornworm Chlordane prepared as a 5-p9rcent dust gave 73 and 30 percent kills, respectively, of these two species on tomato, while a 2-percent dust gave 91 and 43 percent kills. Chlordane in oil emulsion-form at 1:800 gave an excellent, but slow kill on the hornworms with 84 percent kill for s . exta and 80 percent for the other species. — Gould ( l85 lt 182). A 5-percent chlordane dust was the only material that controlled full grown larvae of P. qulnquemaculat a on tomatoes in Florida. — Kel she imer (248). In Ontario chlordane was less effective than DDT which gave good con- trol of the tomato hornworm even at 0.72 pounds per acre. — Pox fit. a],. (152). Tortricidae Argyrotaenia citrana (Fern.), the orange tortrix - 64 - In Oregon a 5-?o r cent chlordane dust, applied to blackberries, gave 41.1 percent control; a 5-pQrcent TDE duat gare 100 percent control. In another test a 5-percent chlordane dust gave 33.6 percent control - the poorest of all insecticides tested. A spray containing 4 pints of chlor- dane emulsion (44 percent chlordane) per 100 gallons of water gave 86.1 percent control which was increased to 91.4 percent when 4 quarts of oil were added to the spray. TDE gave the best control of the sprays tested. — Hosenstiel (399). A chlordane spray (l quart of 44 percent emulsion per 100 gallons of water) gave good control of the larvae of red raspberries in the Puyallup Valley, Washington, "but exhibited phytotoxicity causing a general yellow- ing of the foliage. A wettable powder appeared to be safe. — Johansen and Breakey (242). Ar gyro taenia velutinana (Wlkr.), the red-banded leaf roller Chlordane, 1 pound of 40-percent wettable powder per 100 gallons of water, proved unsatisfactory for the control of the first brood leaf roller in a Maryland apple orchard. — Graham ( 191, ) . In New York in 1948 chlordane as a 50-percent wettable powder proved worthless against second brood. — Glass and Chapman (1 , 79 ) » Chlordane is ineffective.— Eings (392). Choristoneura fumiferana (Clem.), the spruce budworm Chlordane dissolved in benzene-kerosene mixture and applied in a spray tower had very slight effect on the larvae. — Brown ejt, j£« ( 5 . ) . Cnenhasia Ipngana (Haw.), the omniverous leaf tier Chlordane, 1 quart of ^6 percent emulsion per 100 gallons of water, gave negligible kill of the caterpillars on field grown asters at Palo Alto, California.— Pritchard ejb a^. (374). HTMENOPTERA Apidae Aplg mellifera L., the honey bee The effect of chlordane on the honeybee has been observed in California by Eckert ( 122-124 ) and Linsley and MacSwain ( 300 ) ; in Massachusetts by Butler and Shaw (62); in Texas by Weaver (484); in Utah by Knowlton (267): and in Washington by Eide (U2) . Laboratory tests by Eckert (12_3) proved that chlordane it highly toxic to bees as a stomach poison, contact insecticide, and as a f mmigant . When chlordane is fed to bees in a 20-percent sugar sirup, the approximate LD-50 is 1 microgram per bee. The residual action extends over a period of 3 or more weeks under laboratory conditions. - 65 - Later results by Eckert (124) showing the comparative toxicity of the newer insecticides to "bees are presented in the following tahle: Tahle 1. - Th e toxic effect of certain chem icals on honeyhees LD-50 in 72 hours, Chemical, , m icrograms per "bee , Benzene hexachloride 0.15 (90$ gamma isomer) Chlordane 1.21 Aldrin 0.25 TDB lo.O DDT 4.6 (room temp.) 12.0+ (950 J.) Hexaethyl tetraphosphate 0.29 Parathion 0.0? Tetraethyl pyrophosphate 0.75 Toxaphene 22.0 Eckert also oh served that chlordane dusts have reduced the field force of colonies "by from 50 to 80 percent when applied to alfalfa in "bloom. Chlordane in oil (2.5 percent solution) caused the loss of hrood and a portion of the hees when applied in hot weather as an oil spray to grass in front of 30 colonies. A quick removal of the affected colonies prevented much heavier losses. The hees apparently pulled the fumes through the hives hy their ventilating operations. The walls of a comh room were sprayed with a 5-P©rcent chlordane sus- pension in water for the control of ants and one year later enough chlor- dane vapor was present in the room to kill hees within 36 hours. — Eckert and West (125). In lahoratory tests hees in cages were dusted with a pre-determined dose of insecticide at 40 pounds pressure. The dust was allowed to settle for 30 seconds after which the hees were immediately transferred to other cages for ohservation. The toxicity of 10 percent chlordane-40 percent sulfur varied greatly with the temperature. At temperatures helow 76 P. chlordane was only slightly toxic, the MLD "being 29.95 pounds per acre, hut at 86° P. its toxicity increased greatly. — Weaver ( 484 ). Chlordane does not repel hees, hut is very toxic to them if applied while they are active in the field and remains toxic from 12 to 48 hours following its application depending on weather conditions. There is less damage to hee populations from chlordane when used as a spray than when used in the form of a dust. — Mont. Agr. Expt. Sta. ( 331 ). Cephidae Cet)hus cinctus Nort. t wheat stem sawfly A 5-percent chlordane dust at 20 pounds per acre permitted an aver- - 66 - age infestation of 65 percent as compared to 68 percent in the check plot. — Munro ejL aJL. (338). Formicidae Caraponotus her6« per square foot. — Bishopp C22); Bishopp and Knipling (2k); U. S. Bur. Ent. and Plant Quax. (i±68). The relative toxicity of chlordane and DDT to the adult house fly was measured by the "large group" Peet-Grady procedure. Under the conditions of the tests it was found that 0.2-percent DDT or 0.05-percent solutions of chlordane are required to produce a 95 percent mortality in 24 hours. A median lethal concentration was estimated from probit-log dosage curves which indicated that a 0.06-percent solution of DDT or a 0. 02-percent solu- tion of chlordane would be required. — Eearns £t aJL. ( 245 ) . Chlordane acts as a fumigant as shown by tests in which house flies were exposed to vapors from residual deposits. — Hoffman and Lindquist (222). Chlordane was mixed with food and fed to larvae of Musca domertica . Tribollum confusum . Ephestla kuehnlella . and the adults of Sito-ohilus granariuo . The recults obtained with chlordane and with gamma benzene hexa- chloride ar^ very similar, both compounds showing median lethal concentra- tions of less than 50 parts oer million to all four species. — Brown e_£ al . (i2). The toxicity to house flies of surface coating containing chlordane was determined by painting the inside of a small box with riytures of 20 -77 - percent of chlordane and 80 percent of urea- formaldehyde, nitrocellulose, or polymerized diolefins dissolved in a vehicle. The time for knockdown of flies placed in the "box was greater for chlordane than for DDT in all three coatings. — Block Q6, %0 • Flies confined in a small screen-wire cage were exposed for 2-minutes in a 100-cubic foot cabinet in which chlordane dissolved in cyclohexanone had "been sprayed 30 seconds previously. A 5-percent concentration of chlor- dane gave 8 percent knockdown in 30 minutes and 100 percent mortality in 24 hours. The calculated concentrations giving 90 percent mortality were: gamma "benzene hexachloride 0.17; DDT 1.0; chlordane 0.88; and toxaphene 4.9. In residue tests (10 mg. /sq.ft.) chlordare was superior to DDT in kill of flies after 8 weeks. — Gahan e_t al. (l62). A mixture of 0.8 percent of Van Dyk 264 [N-(2-ethylhexyl)bicyclo- (2.2.1 )-5-heptene-2 t 3-dicarDoximide], 0.2 percent of pyrethrins, and 0.2 percent of chlordane in Peet-Grady tests gave a 10-minute knockdown of 99 percent and a 24-hour kill of 98 percent. It requires a concentration of 2 percent of Van Dyk 264 plus 0.025 percent pyrethrins to give satisfactory kill and knockdown of house flies. When 0.2 percent of DDT or chlordane was added, the concentration of the compound could he reduced to 1 percent and a satisfactory kill and knockdown obtained. — Hartzell ( 207 ). Toxicity of insecticides expressed in terms of percent mortality or LD-50 may vary greatly in different laboratories and at different seasons of the year, even if the same equipment was used. Toxicity index, which is used as a relative value to express the toxicity of insecticides, is defined as the ratio between the LD-50 of a standard insecticide and the LD- 50 of the test sample, multiplied by 100. The toxicity of technical chlordane to house flies, determined by the tunnel spray method of Eoan and Kearns, varied from 154 to 190 (alpha chlordane - 100). The toxicity index of alpha chlordane (a stereoisomer of chlordane, m.p. 101-102.5° C.) was 6,^ (diel- drin'rr 100) or 12.1 (aldrin = 100).— Sun ( 447 ) The effect of temperature on speed of knockdown and mortality of house flies exposed to residues of several chlorinated hydrocarbons was deter- mined by exposing house flies (l) continuously at constant temperatures of 70° and 90° F. and (2) for predetermined periods (l to 20 minutes) at 70° and 90° and then holding them for 24 hours at the same temperature at which they were exposed. At a dosage of 50 mg. per square foot chlordane re- quired 100 minutes for knockdown at 70° F. and 63 minutes at 90° F. — Hoffman and Lindquist (223). A deposit of 144 mg. chlordane per square foot of plywood panel killed 100 percent of NAIDM house flies exposed for 5 minutes. — Hansens and G-oddin (2Q2). In 1948 in California a comparison of the chlorinated insecticide for fly control in dairy barns showed BHC to be the most satisfactory material for the replacement of DDT. Only the barn walls were sprayed - not the animals. Chlordane at 50 pounds per 100 gallons of water was slow in knock- down, gave an excellent clean-up, and lasted for from 1 to 4 weeks. — Dietz (102). - 78 - Insecticides were applied on various surfaces and exposed to different environmental conditions in several experiments to determine their residual toxicities to the house fly. DDT and gamma-EEC were initially the most toxic compounds. The other three materials were, in order of their dimin- ishing toxicity, chlordane, Rothane D-3, and toxaphene. BHC gave the most rapid knockdown, followed by DDT, Rho thane D-3, chlorcane, and toxaphene. Vapors from gamma-BHC were about three times as toxic to flies as those from chlordane; both were extremely toxic as fumigants. The order of per- sistence of the residual treatments was, from the most to the least, DDT, Rhothane D-3, toxaphene, chlordane, and BHC. — Bruce (5^)« Cristol (88) in 19^9 examined the hypothesis that the insecticide! activity of various polychloro insecticides is due in large measure to the ability of the compound to liberate hydrogen chloride at the site of action of the insecticide. The relative toxicities to the house fly of the various constituents of technical chlordane were as follows: Relative effective dosares (Technical chlordane = 0.01 ) Heptachlor .00*4-3 Octachlor, active isomer .0056 Octachlor, inactive isomer .017 Nonachlor .020 In reactions with 0.04 M ethanolic sodium hydroxide at k6° C. the insecticidally active octachloro isomer and the nonachloro compound reacted much more rapidly than the heptachloro compound which is the most effective insecticidally, showing that dehydrochlorination with alkali and insecti- cidal activity have no systematic relationship. Gersdorff e_t al « ( 173 ) determined the relative toxicities of certain chlorinated hydrocarbons to the house fly when applied as space sprays using the Campbell turntable method. Crystalline chlordane was about two- thirds as toxic as technical chlordane which proved to be one-fourth as toxic as aldrin and heptachlor. None of the sprays made with the chlorinated compounds caused appreciable knockdown. Organic insecticides in various concentrations and formulations were used to treat 15^ dairy barns in Hew York in 19^+9. Chlordane emulsion, 6, 12, and 2k pounds of toxicant per 100 gallons of water, provided k weeks ox more control of house flies in these barns which were heavily infested before treatment. A mixture of chlordane (6 lbs.) and DDT (3 lbs.) was more effective than either chlordane or DDT alone. — Pimental et a^. ( 367 ) . Same as for Siphona i rritana . — Bruce and Decker ( 56) . Same as for Anopheles quadr imaculatus . — Jay e_t a^ ( 136 ) . Resistant house flies House flies that had developed a resistance to DDT were tested against other insecticides. The special stock was distinctly more resistant to all - 79 - the materials tested than the regular colony. Although a few reversals occurred in the individual tests, none appeared in the final averages at any concentration. To obtain equal mortalities, approximately twice as much toxicant was required for the special stock as for the regular stock with DDT, chlordane, pyrethrum, and rotenone. These tests show that the method of selection resulted in the development of an unusually strong stock of flies rather than one having a specific resistance to DDT. — Wilson and Oakan (428). In tests made in southern California in 1949 against resistant house- flies chlordane, applied as a 40-percent wettable powder at 50 pounds per 100 gallons of spray (approximately 2.5 percent), gave an excellent initial clean-up and in some cases residual action lasted up to one month. In other cases, however, reinfestation was very severe after one to two weeks. The rate of fly knockdown "by chlordane is slower than that of DDT. — March and Metcalf (ii). In samples of flies obtained from seven localities in five states heavy deposits of wettable chlordane and methoxychlor were nonrepellent or even slightly attractive. Eespraying of two "barns with chlordane emulsions and two with suspensions of methoxychlor provided a high degree of control for several weeks. — King and Gahan ( 263 ). Flies from 6 barns in New Jersey which had been sprayed with DDT ex- hibited resistance in laboratory tests to technical DDT and p^'-DDT residues of 144 mg. /square foot. All these resistant flies were killed in tests using residues of chlordane. — Eansens et. al. (204). Specimens of a wild population of house flies that had survived re- peated residual-type applicaions of DDT in Ellenville, New York were cap- tured and offspring were cultured in the laboratory through three genera- tions. Tests were made to determine whether this line of flies was resist- ant to DDT and, other new insecticides as compared with a laboratory line of flies whose ancestors had never been exposed to these insecticides. The results of these tests showed that flies of the Ellenville line were highly resistant to DDT and related compounds, but showed no resistance to certain unrelated chemicals. The results of the tests with technical chlordane are as follows: A total of 18 tests were made in which flies were exposed for 2 hours, 1 hour, 30 minutes, or 15 minutes to surfaces to which 144, 100, 70, or 14.4 mg. of the active material had been applied per square foot of surface. All flies exposed to surfaces to which the three larger concentra- tions had been applied were killed as were those exposed for 1 hour to a surface to which 14.4 mg./ square foot had been applied. The percentages of mortality of flies of the laboratory and Ellenville lines exposed to the latter surface for 30 minutes were 100 and 94«4, respectively, and for 15- minutes exposures they were 95.6 and 60, respectively. The comparative rates of mortality for all tests in which 387 flies of the laboratory line and 459 of the Ellenville line were used, were 99.7 percent for laboratory flies and 98.5 percent for Ellenville flies. — Barber and Schmitt (26). In another series of tests with technical chlordane against these same 2 lines of flies, five tests were made in which flies were exposed - 80 - for 2, 5, 10, or 15 minutes to a surface to which 144 mg. of the active In- gredient had "been applied per square foot. Of the flies exposed for 2 minutes 97.6 percent of the laboratory line and 94.9 percent of the Ellen- ville line were killed. All flies of each line were killed when exposed for the longer periods to this residue. Of 210 flies of the laboratory line exposed to this residue an average of 99»5 percent were killed, and of 208 flies of the Ellenville line similarly exposed 99*0 percent were killed. Five tests were made in which flies were exposed for 15, 30, or 45 minutes or for 1 or 2 hours to a surface to which 14.4 mg. of the active ingredient had been applied per square foot. Of a total of 172 flies of the labora- tory line exposed to these surfaces an average of 66.9 percent were killed and an average of 71 «1 percent of 152 flies of the Ellenville line were killed hy similar exposures. — Barber and Schmitt (27) . In Italy Bettini and Barachini QO. .21) reported that flies resist- ant to high doses of DDT (5*3 g./sq. m.) all died when they came in con- tact with chlordane and BHC. The susceptibility or resistance of the various strains of flies studiei was determined from data obtained "by topical applications of the toxicant to the thorax of female house flies. Acetone solutions of the insecticides were used in all tests. The dosage-mortality data were used to calculate the LD-50 values in terms of micrograms of toxicant per gram weight of fly. The data indicate that the acquisition of tolerance for one insecticide con- tributes to tolerance for the others. The LD-50 of chlordane to the SAIDM strain of flies was 8.2 (DDT ■ 16.8); whereas tc the flies that had become resistant to DDT (LD-50 = 18,728), the LD-50 of chlordane was 15. 6 micro- grams per gram weight of fly. — -Bruce (5*5 ) . Two strains of flies (one laboratory reared, the other collected in the field) were exposed to residues of seven insecticides. The materials tested, in order of decreasing effectiveness to the non-resistant flies, were dieldrin, gamma isomer of benzene hexachloride, aldrin, DDT, chlordane, methoxychlor , and emulsifiable pyrenone. The field collected flies were 7 times more resistant than the laboratory reared flies to DDT. There was no detectable difference in the reaction of the two strains to dieldrin, gamma-BHC, aldrin, chlordane, and emulsifiable pyrenone. — Pimentel and Dewey (366) . In Denmark DDT-resistant and control flies reacted uniformly toward chlordane. — Keiding and Van Deurs (242). In Italy flies resistant to DDT were somewhat more resistant to chlor- dane than were non-DDT-resi3tant flies. — Alessandro and Smiraglia (12) . Experiments with chlordane and other insecticides against DDT-resist- ant flies are critically discussed by Patrissi e^t a^. ( 359 ) . Siphon a lrr jtans (L.), the horn fly In laboratory knockdown tests against the hornfly small screen-wire cages were dipped in preparations containing 0.5 percent of different - Si - chlorinated hydrocarbon insecticides. The methoxychlor caused complete knockdown in 5 minutes, DDT in 8, TDE in 17, chlordane in 53, and toxaphene in 73 minutes in tests made 24 hours after the cages had "been dipped. After 2 months' exposure the methoxychlor, DDT, TDE, toxaphene, and chlordane caused complete knockdown of flies in 12, 62, 152, 248, and 3&0 to 720 minutes, respectively. The cage treated with methoxychlor apparently lost little of its effectiveness. The knockdown of flies exposed to animals treated with the insecticides was the same as that determined in the laboratory, except that a longer time was required.— Eddy and Graham ( 127 ) . Chlordane has "been tested on animals exposed to horn flies in cages, and in field tests on dairy animals in Texas and "beef animals in Kansas. Wettable powder sprays at concentrations of 0.25 and 0.5 percent chlordane (applying an average of approximately 2 quarts per nature animal) have given good control of horn flies. The two concentrations protected animals for about 3 and 4 weeks, respectively. Chlordane was slightly inferior to DDT for the control of horn flies.-— Bishopp and Knipling (.24); Cuff (£2); Laake (280.); Smith (421); U. S. Bur. Ent. and Plant Quar. (46.8) . In Illinois chlordane emulsion was as effective as DDT and TDE (DDD) emulsions in controlling these flies on milk cows. — Bruce and Decker (56^) . Stomoxvs , calcitrans (L»), the stable fly The speed of knockdown and kill and the duration of effectiveness of 11 of the more recently developed organic insecticides were studied in laboratory tests against the stable fly. Two 14-mesh copper-wire cages were dipped in a 1 percent solution of each test material in acetone. One cage was held indoors while its duplicate was stored outdoors, fully ex- posed to the effects of the weather. In the tests made 24 hours after the cages were treated, DDT and methoxychlor proved to be the fastest acting compounds and toxaphene and chlordane the slowest acting. From the stand- point of knockdown and duration of effectiveness, methoxychlor and the bromine analog of DDT appeared to be superior to any of nine other com- pounds tested, including DDT. Parathion, aldrin, and toxaphene appeared to retain their toxic properties longer than did TDE, gamma-BHC (95$), com- pound 153, heptachlor, or chlordane. — Eddy and McGregor ( 128 ). Chlordane, as a 2-percent water suspension made from a 50-percent wet- table powder, proved equal to DDT in the control of house flies and stable flies. — Muma and Hixson (33^). Same as for Sl phona irritans . — Bruce and Decker (56). Psychodidae Psychoda alternata Say, the filter fly In June 1949 filter flies, which had become tolerant to DDT, proved susceptible to chlordane. However, the third and fourth chlordane treat- ments were considered failures. This served again to illustrate the rapid acquisition of insecticide tolerance by insects through the treatment of the larval habitat, the filter bed. —Bruce (i£) . - 82 - Sar c o phag i & ae Many species of flies, including Sar cophagidae, were killed "by chlor- dano 3/^ or 1 pound per acre, applied for the control of grasshoppers. — Severin (413). Simuliidae Slmulium latipes Fries S. Tenustua Say _S. vlttatum Zett. In tests in Alaska a chlordane-acetone suspension was not effective against larvae at 0.5 p. p.m. — Gjullin e_t a^. ( 177 ;. In Alaska chlordane proved inferior to DDT, TDE, and methoxychlor for the control of "black fly larvae. — Travis (4 58 ). Chlordane was tested in the form of a 25-percent emulsion concentrate with 65 percent xylene and 10 percent Triton X-100, also as a 10-percent solution in Yelsicol AR-50 and fuel oil. Chlordane in fuel oil, at 1.185 p.p.m./min., or 1:12,700,000 for 15 minutes, gave partial control for a short distance from the point of application. — Hocking ^t a^.. ( 220 ) . In flume tests on larvae of a "black fly, Sjmulium venustum Say, made in the summer of 19^7 in the White Mountains of New Hampshire, chlordane did not cause 100 percent detachment at 4 p. p.m. — Kindler and Regan ( 2 61 ) . Tabanidae Tab anus sulcifrons Macq. Chlordane is ineffective in protecting animals from attack by horse flies.— Bishopp and KniplingQ4); Knipling (264). Chlordane as a 10-porcent solution in a mixture of Number 1 fuel oil and cyclohexanone was applied at the rate of 2 pounds of toxicant per acre by a plane which flew at 5 to 20 feet above the tree canopy. The effective- ness of the material was determined by counting flies attacking draft horses led through the test plots 1 day before spraying and 1, 2, 3 t 5, euad 7 days after treatment. The results appeared somewhat erratic and no ap- preciable effect on fly populations could be demonstrated for any of the insecticides tried. Tabanus abactor and T. sulcifrons were the two most abundant species. T. atratus . T. vittigpr . T. mul arls. and T. venustus were present in small numbers. A few species of Chr ysops and Sjlvjua were also present. — Howell e_t al. ( 228 ) . Chlordane continues to kill tabanids feeding on livestock for about one day after treatment. — U. S. Bur. Ent . and Plant ^uar . ( ^oc ) . - 83 - Tiypetidae BaS&l try on 1 Jrogg. , a fruit fly In Hew South Wales, chlordane proved inferior to DDT, "benzene hexa- chloride, and tartar emetic for the control of this fruit fly on plum. The chlorinated insecticides were applied as diluted emulsions containing 0.2 percent of the toxicant at fortnightly intervals at the rate of ahout 1 gal- lon per tree. Sugar at the rate of 1 pound per 10 gallons of spray was in- cluded with all three chlorinated insecticides to encourage feeding "by the flies. The bait spray consisted of 2 ounces tartar emetic and 2.5 pounds of sugar in 4 gallons of water, applied at the rate of nearly 9 fluid ounces per tree. At harvest the percentages of undamaged fruits were 93«8 for tartar emetic, 92.3 and 85.9 for the two DDT sprays, 69.7 for benzene hexachloride, and 5^»1 for chlordane. — Allman and Friend (l4) . ^hagoleti s cingulata (Loew) , the cherry fruit fly B. fausta (0. S.), the black cherry fruit fly Chlordane, 50-percent wettable powder at 1 pound of toxicant per 100 gallons of water, greatly reduced the infestation, hut failed to meet the requirement of 99*5 percent of maggot-free fruit. — Cox (86). Rhagoletls pomonella (Walsh), the apple maggot In lahoratory tests at the New York Agricultural Experiment Station in I9J47 chlordane showed a high degree of toxicity. The rate of kill at the higher dosage levels was more rapid than with DDT, although the knockdown rate was slower. — Dean (99) . SIPHDNAPTERA Pulicidae C t eno c e-phal i de 9 spp. When dogs were dipped in a 0. 42-percent technical chlordane emulsion all fleas were dead in 1 hour. No fleas were found at the end of 24 hours on cats similarly dipped. Redipping these cats 7 and 23 days later caused no had effect. — Turk and Batte (460). ACAEINA Ixodidae Amblyomma amer icanum (L . ) t the lone star tick Chlordane dips at concentrations of 0.25, 0.5, 0.75, and 1.5 percent gave complete or nearly complete control of the flat stages on goats and - 84 - cattle and 0.75 and 1.5 percent concentrations caused nearly complete kill of all stages. DDT on the same basis failed to kill all of the engorged forms at 1.5 percent concentration. The two insecticides were about equal in preventing reinfestation. — U. S. Bur. Ent. and Plant iuar. ( 4oc . In preliminary tests at Camp Bullis, Texas, against the lone star tick dusts, applied at the rate of 1 to 2 pounds of chlordane per acre, were superior to DDT dusts applied at the sane rate. A wettable powder and an emulsion containing chlordane when applied a6 sprays to infested cattle at concentration ranging from 0.25 to 1.5 percent chlordane also proved more effective than DDT against the same tick. The two materials, however, ap- peared to be about equal on the basis of duration of effectiveness against reinfestation.— Knipling (264). In tests in Florida chlordane proved promising against the lone star tick when applied as a dust to infested areas, and it appeared to be super- ior to DDT for this purpose. — Knipling ( 265 ) . Dipping dogs in a 0.42 percent technical chlordane emulsion killed all ticks except a few engorged females.— Turk andBatt* (4^0) . Boorihilus microplue- (Canestr.) Four cows were sprayed with a 0.25 percent emulsion of chlordane every 28 days. No female adult ticks reached maturity on these ccv.-3 although they were exposed to heavy larval infestation. — Legg ( 286 ) . Dermacentor alb ip ictus (Pack.), the winter tick Chlordane shows a distinct superiority over DDT against the winter tick on cattle and horses. Nearly complete control of all stages has been ob- tained with sprays at concentrations of 0.75 percent chlordane, whereas I at 1.5 percent killed only a small percentage of the engorged forms. From the standpoint of protection against reinfestation chlordane is also super- ior to DDT, At 0.5 and 0.75 percent chlordane prevents reinf estations for about two months as compared with ^ne month for DDT at the sane concentra- tions. Chlordane as a 5-percer.t cvst has also given good control cf winter ticks and proved superior to DDT. — Biahopp and Knipling (34): U. S. Bur. Int. and Plant Quar . ( 468 ). Dermacentor variabilis (Say), the American dog tick Same as fcr Aml'lyom.ma a^ericanuq . — U. S. Bur. Ent. and Plant -vuar . ( Derrxirrysgus gallinae (Deg.), the chicken mite Dusts containing 2 percent and 5 percent of chl B were dusted into a petri dish, mites were placed on the dusted surface, ?r£ the dish was covered to prevent their escape. There were no dead mites in the ane ter' f 48 hours. — Eixson and Muma ( CI? ) . -85- Otobius megnini (Duges), the ear tick A mixture of 5 parts of chlordane and 95 parts of pine oil introduced into the ears of cattle remained effective for 22 days and was considered at least at effective as a mixture containing 5 percent of BHC in repelling larvae of this tick, — U. S. Bur. Animal Ind. (465). Psoroptidae Psoroptes eaui var. cunlculi (Delafond), the ear mite These mites on a rabbit were not killed when the rabMt was fed chlor- dane. — Knipling et al. (266). Demodicidae Demodex canis Leydig, the dog follicle mite Sarcoptidae Sarcoptes scabiei canis (Gerl.), mange or sarcoptic mite of dogs Jive dogs heavily infested with sarcoptic mange, of which 3 had lesions of demodectic mange, were treated with an emulsion of 0.25 percent chlordane. All treatments were applied by dipping the animals and holding them in the liquid for from thirty to sixty seconds with at least two complet submerg- ences. The dip was warmed to a temperature of 100 to 110° T. Exception- ally large or heavy demodectic lesions were scrubbed with a firm-bristled brush while the animal was in the liquid. The dogs treated with chlordane were allowed to run with untreated animals. One of the chlordane-treated dogs that was heavily infested with sarcoptic and demodectic mange also had several small demodectic lesions three weeks following treatment. As isolation of the test animals was not complete, no further checks on the test were made. None of the animals showed any ill effects from the treat- ments. — Muma and Spencer ( 336 ) . Chlordane was effective in treating common and red mange in dogs. The dogs were dipped in a 50-gallon barrel half filled with a 0,25 percent chlordane solution, and held In the dip for 30 to 60 seconds. — Spencer Gfi2. i£5). Sarcoptes scabiei suis (Gerl.) One application of a 0.25-percent chlordane solution thoroughly applied completely cleaned up sarcoptic swine mange on 800 infested hogs in Nebraska. The 0,25-percent chlordane solution was made by adding 500 ml. of 74-percent emulsifiable concentrate to 50 gallons of water. This was applied with a power sprayer using from 1 to 2 quarts per head with from 50 to 250 pounds of pressure—Spencer (JQadaS) . • pL ^ ^^ Te :ae tranychua cltrl (McG.), the citrus red nite In laboratory tests tha 2U-hour median lethal concentration of chlor- dane to the mite was 1,0 percent. — Metcalf ( 32^ ) . Tetr any chug bloaculatus Harvey, the two-epotted spider mite Dusts containing 2 or 3 percent of chlordane were less effective than containing 5 percent of azobenzene or 0.5 percent of parathion in con- trolling the two-spotted mite on lima "beans, also chlordane sprays of 1 or 2 pounds of 20-percent wettaole powder per 100 gallons of water were less effective than sprays of toxaphene, benzene hexachloride, azobenzene, and hexaethyl tetraphosphate. — Huckett ( 229 / . A spray of chlordane 50-percent wettable powder (0.125 percent chlor- dane) was applied to soybean plants which were then infested with mites. After 19 days the number of live mites on the bean foliage was about the same as in the test where 0.125 percent DDT was applied. The parathion sprayed soybeans showed the lowest populations of mites and eggs at the end i tests.— Vingo and Thomas (502). Tetr any chug pacifjcus McG., the Pacific mite Chlordane at 0.5 pound of 50-percent emulsion for 100 gallons of water controlled Pacific mites well until the end of June, but after that, although the trees were sprayed seven times altogether, control was poor. These tests were made at Yakima, Washington in 19^7 • — Newcomer and Dean Tetranychus spp. Eed spider infestations on cotton developed in some cases where a dust containing 3 percent of chlordane and 3 percent of DIT was used. Against the red spider 10-percent chlordane was more effective than sulfur . — Bishopp (J2) . The red spider on cotton is not controlled by chlordane. — Harned ( ZOO . « In the state of Washington in 19^+7 chlordane proved relatively ineff^c- Lgainst mites, but controlled the woolly aphid to some extent. It dees not seem to have a place in the orchard spray program. — Newcomer ( 2k5) • Trombiculidae a (Eutromblcula) jpJLr (Eutrombicula) alfreddu^esi (Oud.), the chigger Applied as an emulsion, chlordane at 8, 4, and 2 pounds per acre gave - 87 - control equal to that of hydro:cypentamethylflavan at 4 pounds per acre throughout the 17-day period of observation. — Smith and Gouck (422 ) . Applied as a dust or spray at the rate of 2 or 4 pounds per acre, chlordane compared favorably with other miticides, such as "benzene hexa- chloride and hydroxypentamethylflavan. — Knipling ( 264 ) ; U. S. Bur. Ent. and Plant Quar. (468). Trorabidiidae Eutrombldium trigonum (Herm. ), the red grasshopper mite Very few grasshopper mites were killed by chlordane, 3/4 or 1 pound per acre, applied for the control of grashopper.— Sever in ( 413 ,). - 88 - LITERATURE CITED (1) Anonymous 1948. Compatibility chart for insecticides and fungicides. Amer. Trait Grower 68(2): 40-41. (2) 1948. 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Ent. 40: 932-933. (140) 1948. Chlordane for control of Japanese "beetle larvae. Jour. Econ. Ent. 4l: 905-912. (141) Ployd, E. H. 1947. Control of the tomato fruit worm in 1946. Jour. Econ. Ent. 40: 422-423. (142) 1947. DDT and cryolite successful in controlling the tomato fruitworm. La. Agr. Expt. Sta. Ann. Ept. 1945- 1946: 55-56. (143) 1949. Control of the sand wireworm in Louisiana. Jour. Econ B Ent. 42: 9OO-9O3. - 100 - (144) Floyd, I. H. 19^+9. Possible production of late-seaBon roasting ears by use of parathion. La. Agr. Ixpt. Sta. Ann. Ept. 1947-1948: 71-73. (3.45) and Smith, 0. E. 19*49. Chlord&ne as a soil treatment compares favorably with calcium arsenate as a control for the sweet potato weevil. La. Agr. Expt. Sta. Ann. Ept. 1947-19*46: 71. (146) and Smith, C. E. 19*49. Promising results obtained by several insecticides in th* control of thrlps on onions. La. Agr . Expt. Sta. Ann. Ept. 19*4-7-19*+8: 74. (147) and Smith, C. E. 19*49. Control of seed-corn maggot and southern corn rootvorm in corn increases yields. La. Agr. Expt. Sta. Ann. Ept. 19*4-7-19*48: 7*4-76. (148) and Smith, C. E. I949. An economical and practical means of control for the sand wireworm. La. Agr. Expt. Sta. Ann. Ept. 19*4-7- 19*46: 76-77. (1*49) and Smith, C E. 19*4-9* Control of the southern corn rootworm and the seed-corn maggot in Louisiana. Jour. Econ. Ent. 42: 908-910. (150) Eluno, J. A., fiaun, E. S., Deonier, C. C, and Faulkner, F. 19*4-9. Comparative toxicity of DDT and some of the newer insecti- cides to adults of salt-marsh mosquitoes. Mosquito News 9(1): 15-13. (151) Foster, A. C. 19*^8. Phytotoxic effect of DDT and other chlorinated hydro- carbon insecticides. Assoc. South. Agr. Workers Proc. k$t 1*43-1*44. (152) Fowler, B. &., Jr. 19*46. Chlordane gets rid of roaches. Oreg. Farmer 71: 552- 553. (153) Fox, C J., Stlrrett, C. M., Arnott, D. A., and Wressell, H. B. 19*4-9. Chemical control of the tomato hornworm on tobacco in Ontario. Sci. Agr. 29: 553-562. (15*4-) Frazier, N. W. , and Barnes, D. F. 1943. Experiments for control of the grape leaf folder in California. Jour . Econ. Ent. 41: 441-442. - 101- (155) Erear, D. E. H. 1949. What the dealer should know about insecticides. Agr. Chen. 4(5): 25-28, 85. (156) Hilborn, M. T. t and Prince, A. E. 1949. Pest control materials, 19**9« Maine Agr. Expt. Sta. Misc. Publ. 613 j Pa. Agr. Expt. Sta. Progress Ept. 4: 110 pp. (157) Erezal, M. 1948. S-ar 1' action insecticide de l'octochlornaphtalene. Acad. d'Agr. de Erance Compt. Send. 34: 656-660. (158) Erings, H., and f Tousa, J. E. 1950. Toxicity to mice of chlordane vapor and solutions administered cutaneously. Science 111: 658-660, (159) Eronk, W. D., and Dobbins, T. N. 19^9. Insecticide tests for control of the southern corn rootworm in peanuts. U. S. Bur. Ent. and Plant Gjuar. E-782. 10 pp. [Processed.] (160) Pulton, E. A., McBride, 0. C, and Sullivan, W. N. 1949. Toxicity of residues from carbon dioxide-propelled insecticides. Jour. Econ. Ent. 42: 123-126. (161) Eur man, D. P., and Douglass, J. E. 19^8. Comparative evaluations of insecticides for cattle grub control. Jour. Econ. Ent. 41: 783-787. (162) Gahan, J. B. , Gilbert, I. H., Peffly, E. L., and Wilson, H. G. 1948. Comparative toxicity of four chlorinated organic com- pounds to mosquitoes, hcus e flies, and cockroaches. Jour. Econ. Ent. 4l: 795-801. (163) Gaines, J. C. 1947. Tests of insecticides for control of grasshoppers. Jour. Econ. Ent. 40: 896-899. (164) and Dean, H. A. 1948. Tests of insecticides for the control of several cotton insects. Jour. Econ. Ent. 41: 548-554. (165) and Dean, H. A. 19^8. Comparison of insecticides for control of harlequin bugs, Jour. Econ. Ent. 41: 8o8-809» (166) and Dean, H. A, 1948. Comparison of insecticide dusts for grasshopper control. Jour. Econ. Ent. 41: 945-948. - 1C2 - (167) Gaines, J. C. f and Dean, H. A. 19^9* Effect of temperature and humidity on tke toxicity of certain insecticides. Jour. Scon. Ent. 42: 429-433. (168) and Dean, H. A. 1949. Insecticide tests for "boll weevil control during 1948. Jour. Econ. Ent. 42: 795-798. (169) and Dean, H. A. 1949. Comparison of sprays and dusts for grasshopper control. Jour. Icon. Ent. 42: 956-959. (170) Gaines, E. C, and Scales, A. L. 19^8. Effectiveness of insecticides on the "boll weevil in cotton sauares In 19^7. Jour. Econ. Ent. 41: 519-520. (171) Gambrell, E. L. f and Mason, A. C. 19^8. Insecticidal aMphytotoxic properties of plant dips used to control the European chafer. Jour. Econ. Ent: 41: 258-263. (172) Gates, E. H. 1949. Preliminary test for chlordane residue on alfalfa. Bureau of Plant and Insect Control, 3-1-49, Denver, Colorado, 5 PP« [Processed.] (173) Gersdorff, W. A. f Nelson, E. H. , and Millin, 5. 1950* Chlorinated hydrocarbons - the relative toxicity of heptachlor, aldrin, and dieldrin to house flies when applied as space sprays using Campbell turntable method. Soap and Sanit. Chem. 26(4): 137, 139. (174) Gilbert, E. 0. 1948. Chlordane, a pest control. L. A. County Health Dept. Public Health News - Weekly Health Article #102. July 7, 1946. 1 p. [Processed.] (175) Ginahurg, J. M. 1947. Tests with new toxicants in comparison with DDT on mosquito larvae and fish. N. J. Mosquito Extermin. Assoc. Proc. (1947) 34: 132-135. (176) Gjullin, C. M. 1949. Laboratory tests with various new insecticides against the sheep tick. Jour. Econ. Ent. 42: 984-9S5. (177) Cope, 0. 3., Quisenberry, B. P., and DuChanois, P. E. I949. The effect of some insecticides on black fly larvae in Alaskan streams. Jour. Econ. Ent. 42: 100-105. - 103 - (178) Gjullin, C. M., Wilson, C. S. f Travis, B. 7., and Hutton, G. L. 19*49* The relative effectiveness of several insecticides against mosquito larvae in Alaska. Mosquito News 9(4): 142-145. (179) Glass, E. H., and Chapman, P. J. I949. Bed-banded leaf roller problem in New Tork. Jour. Econ. Ent. 42: 29-35. (180) Goldman, L. 1947. Progress report no. 1 [on the reaction of the skin of human subjects to contact with Velsicol 1068], Velsicol Corp. Tech. Bui. 211. 2 pp. [Processed.] (181) Goldsworthy, M. C. 1948. Effect of soil applications of various chlorinated hydrocarbons on the top growth of Blakemore straw- berry plants. Plant Dis. Rptr. 32: 186-188. (182) Gould, E., and Taylor, C. E. 1949* Effect of insecticidal sprays on incidence of peach scab in Vest Virginia. Plant Dis. Rptr. 33: 16-17. (183) Gould, 0. B. 1947. The control of cockroaches. Ind. Agr. Expt. Sta. Ann. Ept. (1946) 59: 62-63. (184) 1947. New chemicals are promising insecticides. Ind. Agr. Expt. Sta. Ann. Ept. (1946) 59: 64-65. (185) 1947. Some notes on the biology and control of tomato horn- worms. Ind. Acad. Sci. Proc. (1946) 56'. 157-162. (186) 1948. New insecticides show promise. Ind. Agr. Expt. Sta. Ann. Ept. (1947) 60: 69. (187) 1948. Tomato hornworm studies. Ind. Agr. Expt. Sta. Ann. Ept. (1947) 60: 70. (188) 1948. DDT eliminates potato leafhoppers. Ind. Agr. Expt. Sta. Ann. Ept. (1947) 60: 70. (189) 1948. New insecticides show promise of roach control. Ind. Agr. Expt. Sta. Ann. Ept. (1947) 60: 72. - 101* - (190) Graham, C. 19^« Control of grasshoppers in apple and peach orchards. Jour. Econ. Ent. kl: 111. (191) 19*+9« Control of the red-banded leaf roller # Jour. Econ. Ent. k2i 35^356. (192) Graham, 0. H. I9/+9. An attempt to protect cattle from grub Infestation "by use of insecticides. Jour. Icon. Ent. i+2: 837. (193) and Eddy, G. W. 19^. Persistence of chlorinated camphene as a fleece worm larvicide. Jour. Econ. Ent. kl: 521 (19^) Granovsky, A. A. 19^+8. Sew chemicals for cutworm control. Minnesota Farm and Home Science 5(2.) 1 1« (195) Greenwood, D. E. 1948. The status of Wireworm control, Connecticut, 19^7 • Conn. Agr. Expt. Sta. Spec. Bui., Feb. 15, 19^8, 3 pp. [Processed. ] (196) Greenwood, M. L. t and Tice, J. M. 19**9« Palatability tests of potatoes grown in soil treated with the insecticides "benzene hexachloride, chlordan, and chlorinated camphene. Jour. Agr. Research 78: ^77-^2. (197) Griffiths, J. T., Jr., and King, J. E. 19^+8. Comparative compatibility and residual toxicity of organic insecticides as based on grasshopper control. Jour. Econ. Ent. kl: 389-392. (198) King, J. E., and Thompson, W. L. 19^7 • Grasshopper control in citrus groves in Florida. Fla. State Hort. Soc. Proc. (19^7) 60: 80-36. Also in Citrus Ind. 29(^): 20-22, 26. 19U8. (199) Gyrisco, G. G., and Marshall, D. S. 1950. Further investigations on the control of the clover root borer in New York. Jour. Econ. Ent. 43: 82-86. (200) Newsom, L. D., Marshall, D. S., and Schwardt, H. H. 19^9 • New advances in alfalfa snout beetle control. Jour. Econ. Ent. kZ: 311-314. - 105 - (201) Hamilton, D. W. 1948. Summer control of pear psylla during 19^-7. Jour. Boon. Ent. 41: 244-248. (202) Hamman, E. 2. 1948. Factors lnrolved in poisoning German roaches by exposing them ^o surfaces treated with chlorinated hydrocarbons. Jour. Econ. Int. 41: 516-517. (203) Hansens, E. J., and Goddin, A. H. 1949 . Eeaction of certain fly strains to DDT and methozychlor deposits. Jour. Econ. Int. 42: 843-844. (204) Schmitt, J. B., and Barber, G. \f. 1948. Eesistance of house flies to residual applications of DDT in New Jersey. Jour. Econ. Ent. 41: 802-803. (205) Earned, E. W. 1947 • The prospects for cotton insect control in 1948. South- eastern Cotton Insect Control Conference Proc, Columbia, S. C, Dec. 8-9, 1947. pp. 28-31. (206) Harrison, P. K. 1949. Laboratory tests of new compounds as insecticides against the sweetpotato weevil. U. S. Bur. Ent. and Plant Q,uar. E-770. 5 pp. [Processed.] (207) Hartzell, A. 1949. Effectiveness of N- (2-Ethylhexyl)B icy clo [2.2.1 ]-5- Heptene-2,3-Dioarboximide on houseflies. Boyce Thompson Inst. Contrib. 15(7): 337-339. (208) Hastings, E., and Pepper, J. H. 1949. Field tests with new insecticides for control of the alfalfa weevil. Jour. Econ. Ent. 42: 55^-55$. (209) Hawkins, J. H., and Thurston, E. 1949. Some phases of European corn borer control in Central Maine. Jour. Econ. Ent. 42: 306-311. (210) Hayslip, N. C. 1948. Eecent advances in the control of animal, pasture f\ry \ corn pests. Everglades Expt. Sta. , Belle Glade, Fla. Mimeographed Ept. No. 12, 8 pp. (211) 1948. A report of insect control investigations for the fiscal year July 1, 1947-1948. Everglades Expt. Sta., Belle Glade, Pla. Mimeographed Ept. No. 17, 26 pp. - 106 - (212) Hayalip, N. C. 1948. Insect control investigations. Vegetable Crops Field Day, Indiantown, Fla. , Apr. 29, 1943. pp. 3-8. [Processed.] (213) Herzfeld, S. H., and Kleiman, M. 1950. l,2-Di^rdroxy-4,5,6,7,3,8-hexaoalo-4,7-methano-3a,4,7,7a- tetrahydroindane and method of preparing sane. U. S. Patent 2,528,654, dated Nov. 7, 1950; appl . July 22, 1943. [Assigned to Velsicol Corp.] (214) and Ordas, E. P. 1950 . l-^Acyloxy-4 , 7-niethano-3a, 4, 7 , 7a-tetrahydr o-4, 5 ,6,7,8,8- hexachlorolndenes and method of producing the same. U. S. Patent 2,523,655, dated Nor. 7, 1950; appl. July 22, 19^8. [Assigned to Velsicol Corp.] (215) and Ordas, I. P. 1950. 1 -Hydroxy-4,7-aethano-3a, 4, 7,7a- tetrahydr 0-4,5,6,7, 8, 8- hexachloroindene and method of preparing same. U. S. Patent 2,528,656, dated Nov. 7,1950; appl. July 22, 1948. [Assigned to Velsicol Corp.] (216) Hetrick, L. A. 1950. The toxicity of some organic insecticides to the eastern subterranean termite. Jour. Econ. Ent. 43: 57-59* (217) Heyi-oth, I. F., and Witherup, S. 1950. Toxicity of chlordane in aerosols. Chem. Spec. Mfrs. Assoc. Proc. 37: 86-88. Dec. 3-5* [Soap and Sanit. Chem. Special Issue.] (218) Hinman, E. J., and Cowan, F. T. 1947. New insecticides in grasshopper control. U. S. Eur. Ent. and Plant Quar. E-722. 21 pp. [Processed.] (219) Hixson, E., and Muaa, M. H. 1947. Toxicity of certain insecticides to the chicken mite. Jour. Econ. Ent. 40: 596-593. (220) Hocking, B., Twinn, C. R., and McDuffie, W. C. 1949. A preliminary evaluation of some insecticides against immature stages of hlackflies ( Diptera Simullidae ) . Sci. A^r. 29(2): 69-30. (221) Hoffman, R. A. I949. Effect of several insecticides on sheep tick pupae. Jour. Ec-»n. Ent. 42: Q34. - 107 - (222) Hoffman, E. A., and Lindquist, A. W. 1949. Fumigating properties of several new insecticides. Jour. Econ. Ent. 42: 436-438. (223) and Lindquist, A. W. 19i+9. Effect of temperature on knockdown and mortality of house flies exposed to residues of several chlorinated hydrocarbon insecticides. Jour. Econ. Ent. 42: 891-893. (224) Roth, A. £., and Lindquist, A. W. 1949. Effect of air temperature on the insecticidal action of some compounds on the sheep tick and on migration of sheep tick on the animal. Jour. Econ. Ent. 42: 893- 896. (225) Hof master, E. N., and Greenwood, D. E. I949. Fall armyworm control on forage and truck crops. Jour, Econ. Ent. 42: 502-506. (226) Hough, W. S. 1948 • Chlordan compared with parathion on plums. Jour. Econ. Ent. 41: 983-984. (227) and Hill, C. H. 1947* Lead arsenate substitutes sought. 7a. Agr. Expt. Sta. Ann. Ept. (1946-1947): 32. (228) Howell, D. E., Eddy, G. W. , and Cuff, E. L. 1949. Effect on horse fly populations of aerial spray applica- tions to wooded areas. Jour. Econ. Ent. 42: 644-646. (229) Huckett, H. C. 1948. Control of the two-spotted spider mite on lima beans, on Long Island. Jour. Econ. Ent. 41: 202-206. (230) Hutson, E. 1948. Grasshopper control in orchards. Mich. State Hort. Soc. Ann. Ept. (19^7) 77: 41-42. (231) Hymen, J. 1946. Perfectionnements apportes ou relatifs a une methode de formation d'une nouvelle composition de matiere et produit qui en resulte. Belgian Patent No. 464,617, Apr. 16, 19^6. (232) 1947» Mejoras en una neuva composicion de materia y el metodo de formarla. Mexican Patent Ho. 45,398, Mar. 19, 1947; applied for Mar. 13, 19^6. - 108 - (233) Hyman, J. 1949* Improvements in or relating to iietkod of forming halogenated organic compounds and the products resulting therefrom. Brit. Patent 618,432; accepted Feb. 22, 1949: applied for March 19, 1946; in the U. S. A. July 25, 1945 and Jan. 26, 19*6. (234) Illinois University College of Agriculture Extension Service 1948. Chlordane for grasshopper control. 111. Agr. Col. Ext. HH24S, 1 p. Mar. 31, 19*8. (235) Ingle, L. 1947. Toxicity of chlordane to white rats. Jour. Econ. Ent. 40: 264-268. (236) Ingram, J. W., Bynum, E. K., and Charpentier, L. J. 1947. Tests with new insecticides for control of the sugarcane borer. Jour. Econ. Ent. 40: 779-761. (237) Ivy, I. E., and Ewing, K. P. 1947. Laboratory and cage tests with newer insecticides to control cotton insects. (Sci. note.) Jour. Econ. Ent. 40: 568-569. (238) Jacobs, J. J. 1949. Chlordane and dermititie. Pests 17(l): 1>14. (239) Jefferson, B. N., and Pence, B. J. 1948. Aster leaf miner-chlordane and benzene heiachloride promising as control insecticides. Calif. Agr. [Calif. Agr. Eipt. Sta.] 2(l): 11-12. (240) and Pence, B. J. 1948. Preliminary experiments on the control of the leaf -miner Liriomyza flaveola on asters. Jour. Econ. Ent. 41: 653-655. (241) Jenkins, J. M. , Jr. 1948, Station resumes flower research. North Carolina Agr. Expt. Sta. Besearch and Farming 7(2): 12, 15. (242) Johansen, C, and Breakey, E. P. 1949. Control of the orange tortrix on red raspberries. Jour. Econ. Ent. 42: 911-91*. (243) Johnson, D. B. 1949. Chemical treatment of seed corn for control of Agpnoderug comma . Jour. Econ. Ent. 42: 801-805. - 109 - (244) Jones, S. C, and Eosenstiel, E. G. 1948. Parathlon for control of the two-spotted mite and certain insects. Jour. Scon. Ent. 41: 118. (245) Kearns, C. v., Ingle, L., and Me teal f, E. L. 1945, A new chlorinated hydrocarbon insecticide. Jour. Econ. Ent. 38: 661-668. (246) Weinman, C. J., and Decker, G. C. 1949. Insecticidal properties of some new chlorinated organic compounds. Jour. Econ. Ent. 42: 127-13*+. (247) Keiding, J., and Van Deurs, H. 1949. DDT resistance in houseflies in Denmark. Nature [London] 163: 964-965. (248) Kelsheimer, X. G. 1947. The control of tomato insects. Market Growers Jour. 76(12): 16, 23. (249) 1947. The use of some organic insecticides in the control of ear worms attacking sweet corn. Tla. State Hort. Soc. Proc. (1947) 60: 121-123. (250) 19^7. Chlordane controls mole-crickets. Fla. Agr. Expt. Sta. Press Bui. 640. 3 pp. (251) 1948. Chlordane for the control of mole-crickets on lawns and golf courses. Timely Turf Topics, Jan. 1948. p. 4. (252) 1948. Chlordane - a useful insecticde in southern agriculture. Down to Earth (Dow Chem. Co.) 4(2): 2-3. (253) 1948. Insect pests on lawns. Fla. Agr. Expt. Sta. Press Bui. 642. 4 pp. (254) 1948. The control of insect pests of cucumher and squash. Market Growers Jour. 77(12): 16, 27. (255) 19^9* Control of insect pests of cucumber and squash. Fla. Agr. Expt. Sta. Bui. 465, 15 pp. - 110 - (256) Kelshelmer, E. G. , Hayslip, 5. C. , and Vilson, J. W. 1950* Control of hudworms, earworms, and other insects attacking sweet corn In Florida. Fla. Agr. Expt. Sta. Bui. 466, 38 pp. (257) Kentucky Agricultural Experiment Station 1947. Insect injury to peaches. Ky. Agr. Expt. Sta. Ann. Hot. (1947) 60: 52-53. (258) 1948, [Control of various insects with chlordane.] Ky. Agr. " Expt. Sta. Ann. Bpt. (1948) 6l: 10, 14-15. 29, 35, 36, 48-49. (259) Kerr, T. ¥., Jr. 1948. Control of the cornfield ant in golf greens. Jour. Econ. Ent. 41: 48-52. (260) 1950. Insecticides for control of certain insects attacking oxnwnental trees and shrubs. Jour. Econ. Ent. 43: 63-65. (261) Kindler, J. B., and Began, F. B. 1949. Larricide tests on blackflies in New Hampshire. Mosquito News 9: 108-112. (262) King, J. B. t and Griffiths, J. T., Jr. 1948. Beeults of the use of concentrated sprays in citrus groves in Florida. Florida Entomologist 31: 29, 31-34. (263) King, V. V., and Gahan, J. B. 1949. Failure of DDT to control house flies. Jour. Econ. Ent. 42: 405-409. (264) Knipling, E. F. 1947. Newer synthetic insecticides. Soap and Sanit. Chem. 23(7): 127, 129, 131. (265) 1947. Becent developments in insecticides of interest to pest control operators. Pests 15(2): 10, 12, 14. (266) Bushland, B. C, Babers, F. H., Culpepper, G. H. , and Baun , E . S . 1948. Evaluation of selected insecticides and drugs as chemo- therapeutic agents against external "bloodsucking parasites. Jour. Parasitology 34: 55-70. (267) Knowlton, G. F. 1947. Beduce bee losses. Beekeepers' Mag. 10(1C): 27-2e. - Ill - (268) Krijgsman, B. J., and Berger, N. E. 1949. A simple method for the estimation of contact insecti- cides. Bui. Ent. Res. 40: 355-358. (269) Kruse, C. W. 1948. Roach control. S ap and Sanit. Chem. 24(ll): 131, 133, 135, 137, 139, 169. (270) Kulash, W. M. 1947. Benzene hexachloride, DDT, and chlordane for Colorado potato "beetle control. Jour. Econ. Ent. 40: 640-643. (271) 1947. Results obtained from use of various insecticides in cotton insect control at North Carolina Experiment Stations. Southeastern Cotton Insect Control Conference Proc. Columbia, S. C., Dec. 8-9, 194? 5 pp. 19-22. (272) 1947. Benzene hexachloride and chlordane to control cotton "boll weevil. Jour. Econ. Ent. 40: 644-650. (273) 1948. New insecticides for corn earworm control. Jour. Econ. Ent. 41: 387-389. (274) 194-8. Dust treatments for fall armvworn control in North Carolina. Jour. Econ. Ent. 4-1: 822-823. (275) 1948. New insecticides for cotton insect control. Jour. Econ. Ent. 41: 986-987. (276) 1948. Wireworm - enemy of row crops. North Carolina Agr. Expt. Sta. Research and Farming 7(2): 4-5. (277) 1949. Further tests with soil insecticides to control southern corn rootworm. Jour. Econ. Ent. 42: 558-559. (278) 1949. Soil insecticides for control of cutworms. Jour. Econ, Ent. 42: 705-707. (279) Kyd, S. 1948. New insecticides for grasshopper control. Okla. Agr. Col. Ext. "Cir. 483. 3 pp. - 112 - (280) Laake, 2. W. 1949. Chlorinated hydrocarbon Insecticides for the control of the horn fly on "beef cattle in Kansas and Missouri. Jour. Econ. Ent. 42: 143-144. (281) Lange, V. H., Jr. 1947. New developments in soil insecticides. Agr . Chem. 2(9): 20-23, 68-69. (282) Carlson, E. C., and Leach, L. D. 1949* Seed treatments for wireworm control with particular reference to the use of lindane. Jour. Econ. Ent. 42: 942-955. (283) and Smith, L. M. 19^7. Control of a leaf miner on peas. Jour. Eccn. Ent. 40: ^96-499. (284) Langford, G. S., and Squires, D. W. 1947. DDT, benzene, hexachloride, and chlordane for Japanese beetle control. Jour. Econ. Ent. 40: 269-270. (285) Laudani, H. , and Marzke, F. 0. 1949» Toxicity to fabric insects and resistance to washing and dry cleaning of six chlorinated hydrocarbon insecti- cides. Jour. Econ. Ent. 42: 434-436. (286) Legg, J. 1949. A preliminary note on the use of two recently introduced insecticides, chlordane and toxaphene, in the control of the cattle tick ( Bop-philus mlcroolus ). Austral. Vet. Jour. 25: 65-66. (237) Lehman, A. J. 1948. ' The pharmacology of the newer insecticides. U. S. Food and Drug Adra. 3 pp. [Processed.] (288) 1948. The toxicology of the newer agricultural chemicals. Assoc, Food and Drug Official* U. S. Quart. Bui. 12(3): 82-89. (289) 1948. The toxicology of the newer insecticides. Internatl. Cong. Trop. Med. and Malaria Abs. 4: 139-140. (290) 1949. The major toxic actions of insecticides. Bui. N. Y. Acad. Med. 25(6): 382-387. (291) 1949. Toxic action of insecticides. Soap and Sanit. Chem. Blue Book 1949, 173-175: Amer . Profess. Pharmacist 15: °07- 011, 938-939. - 113 - (292) Lehman, A. J. 19l+9» Pharmacological considerations of insecticides. Assoc. Food and Drug Officials,U. S., Quart. Bui, 13(2): 65-70. (293) I9J+9. The toxicology of the newer agricultural chemicals. Pesta 17(1): 7. (294) 1950. Classifies pesticides from public hazard standpoint. Food Packer 31(7): 3^35. (295) 1950. Some toxicologieal reasons why certain chemicals may or may not he permitted as food additives. Assoc. Pood and Drug Officials, U. S.^uart. Bui. lM3): 82. (296) Lemmon, A. B. 19^*8. Bio-assay of (economic poisons. Pests 16(12): 10,12, 14. (297) Lepage, H. S., Giannotti, 0., and Orlando, A. 19^7. Experiments on the chemical control of the South American migratory locust Schistocerca cancellata Serv. Inst. Biol. [Sao Paulo] Arch. 18(8): 135-160. (298) Lidor, B. E. , Knous, H., and Beckwith, C. I9I+8. EmulsifiaDle concentrates of chlordane. Soap and Sanit. 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A. 1943. Insecticide emulsions easier to ship, safer to use. Chem. Indus. 62: 233-240. L2) \8. Household insecticides. Chen. Indus. 63: 391. (313) March, R. 3., and Metcalf, R. L. 1949. Laooratory and field studies of DDT resistant he in Southern California. Calif. Dept. Agr. Bui. 38: 93-101. (314) Marshall, D. S. f Nev/som, L. D. , Gyrisco, G. G., an^ Schw .. . K. 1940. Control of the clover root horer . Jour. Econ. 2nt. 315-313. 115 - (315) Marshall, G. E. 19^8, The before harvest story of peach pest control in 1948. Hoosier Hort. 30(10): 147-150. (316) 1948. The control of the major insect pests and diseases of peaches. Ind. Acad. Sci. Proc. 57: 116-118. (317) 1949. Interrelation of peach insects and disease control at Orleans, Indiana. Jour. Econ. Ent. 42: 3o6~8lO. (318) Mason, A. C, and Chisholm, E. D. 1949. An ethylene dibromide-chlordan mixture to control soil- inhabiting stages of the Japanese "beetle. Jour. Econ. Bat. 42: 639-641. (319) Maxwell, C. W. B. 1948. Control of the strawberry weevil, A nthpnoama signatus . Ent. Soc. Ontario Ann. Ept. (194?) 78: 51^56. (320) Medler, J. T., and Chamherlin, T. S. 1948. Seed yields of red and Ladino clovers increased "by us« of insecticides. Jour. Econ. Ent. 41: 108-109. (321) and Chamberlin, T. E. 1949. Low pressure spraying equipment for control of some forage insects. Jour. Econ. Ent. 42: 239-243. (322) Metcalf , E. L. 1947. Eelative toxicities of isomeric hexachlorocyclohexanes and related materials to thrlps. Jour. Econ. Ent. 40: 522-525. (323) 1948. Insecticidal activity of 2,2-bls-(2-chlorothienyl)-l,l,l- tr i chl or o ethane. Science 108: 8*j-85* (324) 1948. Acaricidal properties of organic compounds related to DDT. Jour. Econ, Ent. 4l: 875-882. (325) Carlson, R. 3., and Murphy, U. E. 1948. Development of new pest-control insecticides. Citrus Leaves 28(9): 8-9; Calif. Citrograph 33: 523 % 538. (326) Michelbacher, A. E. 1948. Possible effects of new insecticides used in mosquito control on economic entomology. Calif. Mosquito Control Assoc. Proc. & Papers 1943: 20-22. (327) Michelbacher, A. E. , and Mlddlekauff, W. V. 1949. Codling Both investigations on the Payne variety of English walnut in Northern California. Jour. Icon. Ent. 42: 736-7^6. (323) Missouri Agricultural Extension Service 1947. Spraying suggestions for commercial apple orchards, 1947. Mo. Col. Agr. Exten. Serr. Cir. 540, l6 pp. (329) 1948. Spraying suggestions for commercial apple orchards, 1948. Mo. Col. Agr. Exten. Serv. Cir. 553, 12 pp. (330) Mitchener, A. V. 19^9. Chlorinated camphene, chlordan, DDT, and calcium arsenate compared for control of the Colorado potato beetle. Jour. Econ. Ent . 42: 152-153. (331) Montana State College 19^9. Recommendations for the use aad quidance of aircraft operators in the application of sprays and dusti for the control of injects, weeds, and plant diseases. Mont. Agr. Col. Ext. 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U(l): 11. - 117 - (338) Munro, J. A., Nostdahl, W., and Post, R. L. 1949. Wheat stem sawfly. N. Dak. Agr. Expt. Sta. Bimonthly Bui. 11(3): 35-91. (339) and Post, R. L. 1949. Control of boxelelder "bugs. Jour. Econ. Ent. 42: 994. (340) Post, R. L., and Hoyman, W. G. 1947. Effect of Insecticides on tuber yield and control recom- mendations for 1947. N. Dak. Agr. Expt. Sta. Bimonthly Bui. 9: 109-110. (341) Murphy, W. J. 1947. What's in a name? Chem. and Engin. News 25: 2253. (342) Nagasawa, S. 1949. Comparison of the toxicity of gamma-BHC, 1068, and p,p'- DDT to the pupa of the common house mosquito. (In Japanese,) Botyu-Kagaku 11: 20-23. (343) Neiswander, R. B. 1949. The grape mealybug on Taxua in Ohio. Jour. Econ. Ent. 42: 41-44. (344) Nettles, W. C, and Lewis, J. M. 1949» New insecticides for insect control on flue cured tobacco. Clemson Agr. Col. Ext. Serv. Cir. 328, 8 pp. (345) Newcomer, B. J. 1948. Evaluation of materials for controlling orchard mites and the woolly apple aphid. Wash. State Hort. Assoc. Proc. (1947) 43: 19-23. (346) and Dean, P. P. 1948. Studies of orchard acaricides. Jour. Econ. Ent. 41: 691-694. (347) Newsom, L. D., Roussel, J. S., and Smith, C. E. 1948. Cotton insect studies. Several organic chemicals show promise as cotton insect poisons. La. Agr. Exot. Sta. Ann. Rpt. 1946-1947: 52-53. (348) and Smith, C. E. 1949. Thrips as pests of seedling cotton. La. Agr. Expt. Sta. Ann. Rpt. 1947-1948: 68-69. (349) Smith, C. E., Clower, D. P., and Pfrimmer, T. F. 1949. Chlorinated insecticides are more destructive to bene- ficial insects than calcium ar senate-nicotine. La. Agr. Ixpt. Sta. Ann. Rpt. 1947-1948: 68. - 116 - (350) Newsom, L. D., Smith, C. E., Pfrimmer, T. F., and Clover, D. F. 19^9. Comparison of several insecticides for control of cotton pests. La. Agr. Expt. Sta. Ann. Bpt. 19^7-19^: 66. (351) Nickels, C. B. 19^+9. DDT and other insecticides to control the pecan nut case-bearer. Jour. Econ. Ent. J+2: 357-359. (352) Niswander, B. E., and Davidson, B. H. 19^*8. A comparison of the toxicity of some new insecticides to the German roach. Jour. Econ. Ent. kl: 652-653. (353) North Carolina Agricultural Experiment Station 19^3« Soil treatments prove effective on wireworms. North Carolina Agr. Expt. Sta. Ann. Ept. 70 (1947): Eesearch and Farming 6(3)2 10. (35^) Osburn, M. E. 19^*8. Comparison of DDT, chlordane, and chlorinated camphene for control of the little fire ant. Fla. Ent. 3l(l): 11-15. (355) Palumbo, M. 19^9» Color reaction to identify and determine Octa Klor (clordan). Farm. sci. e tec. (Pavla) if: 531-535. (356) Parker, J. E. 19^-7 • Comments and suggestions on locust control in Argentina. U. S. Bur. Ent. and Plant Q,uar. E-73^. Ik pp. [Processed.] (357) 19^9. Tests of insecticides for grasshopper control, 19^7. U. S. Bur. Ent. and Plant Quar. E-77^, 18 pp. [Processed. ] (353) and Wakeland, C. l$kQ» New insecticides for grasshopper control. U. S. Bur. Ent. and Plant Quar. 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Laboratory tests with house flies and house fly larvae resistant to DDT. Jour. Econ. Ent. 43: 105. (367) Schwardt, H. H., and Norton, L. B. 195C House fly control in dairy barns. Jour. Econ. Ent. 43: 510-515. (368) Plummer, C. C, and Shaw, J. G-. 1947. Toxicants in oils for control of the citrus blackfly. Jour. Econ. Ent. 40: 499-504. (369) Post, G. 1949. Two new insecticides; the present knowledge of the effect of toxaphene and chlordane on game birds of Wyoming. Wyoming Wild Life 13 (4): 8-13, 37-38. (370) Post, R. L., Colberg, W. J., and Munro, J, A. 19^+8. Effect of insecticides on tuber yield. N. Dak. Agr. Expt. Sta. Bimonthly Bui. 10(3): 98-IOO. (371) Munro, J. A., and Colberg, W. J. 1947. DDT more effective than chlordane in control of weevils on peas. N. Dak. Agr. Expt. Sta. 1947 Ann. Ent. Progress Rpt. 1 p. [Processed.] (372) Powell, D., Chandler, S. C, and Kelley, 7. W. 1948. Pest control in commercial fruit plantings. Univ. 111. Col. Agr. Ext. Serv. 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(39*0 Ristich, S. S., and Schwardt, H. H. 19^9* Biology and control of the seed-corn maggot on "beans in New York. Jour. Econ. Ent. 42: 77-80. (395) Ritcher, P. 0. 19*+8» Insects injuring strawberries. Ky. Agr. Expt. Sta. Kentucky Fruit Notes 3(6): 6-7. (396) 19*»9 • New materials for control of strawberry crown borer. Jour. Econ. Ent. 42: 838-839. (397) and Armstrong, W. D. 1948. Experience with curculio in Kentucky. Ind. Hort. Soc. Trans. (19^+7) 87: 16-21. - 122 - (398) Eomano, X. 1950. Cklordan determination. Ann. Sper. agrar. (Borne) 4: 295-306. (399) Bosenstiel, *. G. 1949. Life history and control of the orange tortrix in Oregon. Jour. Icon. Int. 42: 37-40. (400) Both, A. E., Yates, V. W., and Llndquist, A. V. 1947» Preliminary studies of larricide6 on snow-water mosquitoes, Mosquito News 7(4): 154-156. (401) Russell, X. X. 1949* Test 8 with DDT, chlordane, tozaphene, and benzene hexa- chloride for control of Lygus spp. on seed alfalfa in southern Arizona, 1945-1948. U. S. Bur. 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