OF with i flB^^^ ~ it Stations , Non-Federal Rese.. In order to further research on the im tiv Entomology and Plant Quarantine has invited State i submit for reproduction and distribution, especially ji~ , the results of experiments with DDT conducted mainly du,. j4 doing this, no review of the material submitted by the various agencies has been made by the Bureau, The only change that has been made in the statements as submitted has been alteration in arrangement to make them as much as possible uniform in style, and t in some instances, inserting scientific names i There is a heavy demand for information regarding methods of formula- tion, application and results of the use of DDT on various crops and against many insects. It is felt that the information obtained by various research workers in this field will accelerate the quest for more effective methods of controlling pests of food, forest and fibre crops as well as those of livestock and man. Some duplication of effort may also be avoided and per- haps more complete coverage of insect problems may be obtained by distrib- uting results of experimental work promptly among research groups. It should be borne in mind that these results are necessarily of a preliminary nature and that avoidance of definite recommendations has been purposeful. Attention is also directed to the need for constant considera- tion of related but nonetheless important aspects of the introduction and widespread use of a new insecticide^' These include the effect of such materials on beneficial insects and wildlife, on plants both directly and through accumulations in the soil, and the ever present matter of residues that may be unsightly or may prove toxic to man and domestic animals.. These reports on DDT experiments are not presented in any particular order with reference to subject-matter, date of receipt, or otherwise. The contributions are all being given the same "E dumber" (E-6I4I1.) with an added letter to designate the different contributions. ( Ma y i94S ; ' ' - ¥ STATE PLANT BOARD ' ^ 644t ' ^ UNITED STATES DEPARTMENT OP AGRICULTURE AGRICULTURAL RESEARCH ADMINISTRATION BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE Experiments with DDT Conducted "by State Agricultural Experiment Stations, Agricultural Colleges, and Other Non-Federal Research Organizations DIVISION OF ENTOMOLOGY AND ECONOMIC ZOOLOGY, UNIVERSITY OF MINNESOTA, ST. PAUL, MINNESOTA Potato Insects ' In 1944 field experiments similar to those of 1943 were conducted with DDT using commercial fields of potatoes and the plots at the Experi- ment Station. Near East Grand Forks, Minn,, 3 applications were made of 2 distinct dusts, 1 at 5 percent of DDT alone in Pyrax and the other at the same strength and 5 percent of yellow copper oxide at the rates of 15, 20, and 25 pounds per acre in each successive treatment between July 8 and August 3, 1944, on 1.73 acres each in comparison with 11 other insecticidal combinations. At Crookston, factorial experiments consisted of 18 different treat- ments, 4 of which consisted of DDT, applied 3 times at 15, 20, and 25 pounds per acre, on 0,216 acre area each. 1, - DDT at 5 percent alone in pyrophyllite. 2, - DDT at 5 percent with 5 percent of yellow copper oxide in the same carrier. * - 3, - DDT at 5 percent with tribasic copper sulphate at the level of 7 percent of metallic oopper-in pyrophyllite. 4, - DDT at 1 percent with 5 percent of yellow copper oxide in pyrophyllite. Near Fisher, Minn,, four DDT dusts at 25 pounds per acre were used for residual value over 2.544 acres each. All dusts used in pyrophyllite carrier as follows: 1, - DDT at 5 percent alone, 2, - DDT at 5 percent with 5 percent of yellow copper oxide. 3, - DDT at 3' percent with 5 percent of yellow copper oxide. 4, - DDT at 1 percent with 5 percent of yellow copper oxide. In addition to these experiments a field of 2,5 acres of potatoes was dusted by an airplane, using 5 percent DDT dust with 5 percent of yellow copper oxide at 25 pounds per acre. x \ _ 2 - On the basis of those experiments it is apparent that DDT proves to be one of the outstanding insecticides for the control of most of the potato insects, confirming the previously reported results. From 2 years of experiments, it is evident that while DDT has a considerable residual value on foliage under field conditions, it certainly does not possess very long residual properties outdoors as compared with the indoor experi- ments. The combination of DDT with 5 percent of yellow copper oxide, as a rule, gave quite consistently somewhat more effective control of most of the potato insects than the same concentrations of DDT alone. .„.. A. A. Granovsky POTATO PLEABEETLE. — Epitrix cucumeris (Harr.) is effectively controlled by as low concentrations as one percent, especially when the dust actually -hits the insects. Almost without exception the counts of fleabeetles at the end of 24 hours after dusting reveal a nearly complete mortality. In •repeated .applications highly significant differences between treatment means were obtained. Residual value of a single application of 5 percent DDT, against the high population of emerging second brood showed that treatment means do not differ significantly from the check. POTATO LE CHOPPER.— Enroo a sea fabae (Harris) is controlled best by the higher concentrations of DDT used. In the majority of the tests at re- peated applications, the analysis' of variance reveals highly significant differences between treatment means. The residual value conspicuously gave more satisfactory kill of the young nymphs than the adult leafhoppers. ..as MIRIDS. — The mirids, such /Lygu s o r a t e n,sj s oblinea.tus (Say), Adeloho cori s lineola tus (G-oeze), and A. rnxiidus (Say) also' respond to treatments by DDT, usually by highly significant differences between means, although the re- sults are not always consistent. COLORADO POTATO BEETLE.— Lent i no tar sa decemlineata (Say) was killed with remarkable ease in the adult and nynphal stages within 24 or 36 hours after dusting. Track Crop Insects : During 1944, DDT was extensively used in a series of experiments against various truck crop insects in Minnesota. Specially designed tests were made for the control of the leafhoppers in carrots, the. corn earworm in sweet corn, melon and cabbage insects, onion thrips, and .others. A brief summary of the tests is here -presented. « - 3 - SIX-SPOTTED LEAFHOPPER ( Macro steles divisus ( Uhler) ) .-—Associating with virus disease, this insect cruses serious damage to commercial carrot crops. A large carrot field was divided into randomized and replicated plots with an area of 1.335 acres for each of the six treatments, two of which contained DDT at 20 and 25 pounds per acre in three applications per season. 1. - DDT at 5 percent alone in pyrophyllite . 2. - DDT at 5 percent with 5 percent of yellow copper oxide in pyrophyllite. Both combinations of DDT gave very satisfactory results in controlling this insect, and in giving a much greater percentage of disease-free carrots as compared with other plots, CORN SARWORM. — In testing six different methods of ear treatment in replicate plots the DDT dusted plot had 3.56 percent infested ears as against 7,26 percent in % the check and. only 0.99 percent in the oil treat- ment,- CABBAGE INSECTS. — The imported cabbage worm, Pieris rapae (L.), the cabbage looper, Aut piranha bra ssicae ( Riley) ,• and the diamondback moth, Plutella m aculipennis ( Curt.) larvae were completely controlled by a 5 per- cent DDT dust in combination with 5 percent of yellow copper oxide in pyrophyllite dusted lightly five times during the season. The plants in the check plots were so badly riddled that not a. single edible head was formed. The DDT dust was by far the most effective of several insecticides tried. The ca/bbage plants treated with a DDT combination were absolutely free from holes and assumed a healthier and conspicuously greener appear- ance in comparison with all other plots. ' MELON INSECTS. — The squash bug, Ana sa tristis (Deg.) in adult and nymphal stages, and the cucumber beetles, Diabrotica v ittata (F.) and D. duodecinvounctata (P.), were very effectively controlled in replicated plots, established in heavily infested commercial plantings by 5 percent of DDT alone and in combination with 5 percent of yellow copper oxide. On the Sther hand, they completely failed to control the melon aphid, Aphis £0 s syp i i Glov., which seriously damaged some of the dusted plants. 3EAN LEAF BEETLE.— Controlled by 5 percent of DDT in pyrophyllite in a small patch of beans grown in a victory garden. DNIOft TKRIPS. — Preliminary laboratory tests with several concentrations of DDT dusts and sprays showed a definite possibility for controlling this pest, especially by higher concentrations of DDT. A. A. Granovsky Miscellaneous Insects A few additional experimental uses of DDT were made during 1944, especially for the protection of young apple nursery stock and against greenhouse insects and others. \ - 4 - LEAFHOPPERS AltD "APPLE APHID. — Apple nursery stock at Faribault, Minn., was. dusted with a 5 percent DDT dust twice during the ■ season' at 1-month intervals, comparing 'its effectiveness with six applications of. 4-4-50 "bordeaux mixture between June 21 and August 12, 1944, 'also using a- check. The last three bordeaux sprays were mixed with nicotine sulphate at 3/4 pint per 100 gallons. Both treatments controlled the leafhoppers about equally well. Nicotine, sulphate took fairly good care of Aphis pomi Deg. in the bordeaux block. afid the aphid population in the 'DDT block-" was not greater, showing that" DDT controlled some of them. 'The average -'annual growth in the DDT block measured 17.23 inches, -in the bordeaux block 15.55 inches, and in the control block 16.05 inches, showing that frequent bordeaux application depresses, while dusting with DDT slightly increases the annual growth of young appie nursery stock. DEPLUMING uITE ( Cnemidocoptes gallinae Baill.) . — A potato grower, coopera- ting in the experimental control of potato insects, complained that his chickens do not thrive and are losing feathers. Upon examination it was found that they were badly infested with depluming mites. The hen house and the chickens were dusted with a 5 percent DDT dust. After 2- weeks, the treated chickens were almost completely free from the mites and began to put on' new feathers. The' 'second application completely rid the birds of the pest. A. A. Granovsky Insects Affecting Kan and Animals HOUSEFLIES A1ID STABLEFLIES. — Two' methods of utilizing DDT were .used to control flies in barns. In one test all the screens were painted with 5 percent DDT in kerosene. In the other experiments Neocid'A-5 or Neocid A-20 were used as water suspensions and sprayed on the walls and ceiling. [Painting the screens resulted in the killing of large numbers of house- flies and stableflies, but the amount of surface ■ treated wa s too small to give satisfactory control. It is estimated that the population was reduced by 30-40 .percent after the screens were treated. A water suspension of 2 percent of Heocid A-5 gave fair control for about 1 month when apiDlied to walls and ceiling as a coarse spray. Both a' 1 percent and a' 2 percent suspension of ITeocid A-20 gave much better con- trol, with the latter' giving good results for 6-8 weeks. One barn with about 5,000 square feet of sprayed surface was kept free of flies all summer with two applications of 18 gallons each of a 2 percent* suspension of Neocid A-20. A. C. Hodson STATE PLANT BOARD UNITED STATES DEPARTMENT OF ACrRTCTTr/TURE AGRICTUI TT RAL RESEARCH ADMINISTRATION BUREAU OF RNTOfaQGY AND PLANT QUARANTINE Experiments with DriT Conducted by State Agricultural Experiment Stations, Agricultural Colleges, and Other Non-Federal Research. Organizations ' • Department of Zoology and Entomology Mississippi Experiment Station ; * . State College, Miss. ( Note : The test against the pickleworm was a regularly approved Mis sis sd ppi Experiment Station project. All the other tests were conducted after hours or when spare time could be found and it was not possible in some cases to give the attention to details which would have been desirable. The DDT dusts used in these tests were furnished by 'the Geigy Company as Gesarol A-l, A -2 and A-3») Vegetable Insects PICKLE T 70RM«-"«-This test was made on an acre of cantaloups which was divided into 60 plots. Treatments Included 1%, 2$, 3$ DDT dusts, l/2$ rotenone in Pyrax, and a mixture of 30$ cryolite (Kryocide) , 6$ Cuprocide, and 64$ Pyrax, each replicated 10 times. Dusting began at blooming and. was continued at weekly intervals until 10 days before harvesting started. Four effective applications were made at 15 to 20 pounds per acre for the first and 25 to 30 pounds per -acre for the last. The average percentage of infested melons at harvest was as follows: 1$ DDT 5.5< (Range — — to 15) 2% DDT - — 4.4$ (Range— — tell. 6) 3$ DDT : - — 4.4$ (Range — — to 9) 1/2$ Rotenone— 8.9$ (Range — —3.9 to 18.8) 30$ Cryolite 7.3$ (Range — —4.2 to 17) Check — 11.2$ (Range — —6.8 to 20) It is believed results would have been considerably better if applica- tions had been continued until harvesting bepan or even later. SQUASH RUG. — This test was conducted in the field on mature squash plants already severely damaged by a heavy infestation of half-grown and older nymphs and adults; hence the number present was not known. 'Dusts containing 1, 2, and 3$ DDT and a spray of 1 pound DDT in 100 gallons of water were applied. At the end of 24 hours both adults and nymphs were still active in sXX treatments. After 48 hours very few bugs were seen. Careful examination 72 hours after the application shovred large numbers killed by each treatment, but a few nymphs and adults survived each one, the largest number of each being in the cage receiving the spray. General Plant Feeders A LEAF-FOOTED BUG ( Leptoglossus phyllopus (L.) ) .—This bug occurs in thou- sands on cowpeas in Mississippi in late summer. Using cowpea plants in screened cages 20" x 20" x24," with 25 adults in each test, the following treatments were given, beginning September 7: ! Record of mortality No. : Treatment ; 24 hrs. : 48 hrs.. : 4 days; 9 days 1 Check — No treatment 1 4 5 7 2 Plant and bugs dusted with Jfo PDT 15 24 25 3 Plant only dusted with % DDT 5 5 24 4 Plant only sd rayed with 1 lb . DDT in 100 gal. H 3 3 7 24 o In another test a 1^ DDT dust aorlied directly to the adults gave no mortality in 24 hours, 56^ in 48 hours, and 70°' in 72 hours. A 2< dust applied directly gave 70^ dead in 24 hours and 85^ in 48 hours. Euschistus servus (Say) . — This pentatomid is often very numerous on cotton, okra, beans, and other croos. Practically no mortality occurred within 7 2 hours after a group of adults was dusted with 2^ DDT. Absence of the writer on extension and regulatory work prevented further records. Insects Attacking: Ornamentals A LACEBtfG ( Corythucha cydoniae (Fitch,)). — This insect usually defoliates several species of the ornamental shrub Pyracantha in Mississippi unless controlled. On September 20, branches of Pyracantha well infested with lacebugs were placed in beakers of water in the laboratory, the branches drooping over large sheets of white paper to catch the insects which fell as a result of the treatments, as it was practically impossible to count the live insects on the branches on account of the numbers of adults and nymphs. In treatments 1 to 4, inclusive, some adults and nymphs had fallen to the, paper 6 hours after treatment and they continued to drop as time progressed. A few dead nymphs were observed 10 hours after treatments 2 and 3 were applied. In the check, treatment 5, no insects were observed •n the paper. The results 24 hours and 5 days after treatment we're as follows: " 1 several | U Q 1 1% DDT dust 19 many 2 2 2% DDT dust 20 4 o % DDT dust 11 some a Spray, 1 lb- D oT P er 100 g 5 Check— untreated . — DDT . Exa-"f h l0 ^ p ayS B y a october 10 the shrub ^^^ataent showed g^»Lff»££ alnost defollated Clay lyle May 194 5 . UNITED STATES DEPARTMENT OF AGRICULTURE AGRICULTURAL RESEARCH ADMINISTRATION BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE Experiments with DDT Conducted by State Agricultural ' Experiment Stations, Agricultural Colleges, and Other Non-Federal Research Organizations AGRICULTURAL EXPERIMENT STATION, OREGON STATE COLLEGE, CORVALLIS, OREGON Vegetable Insects Field tests for control of potato insect pests were planned in 1944 to determine (1) the effectiveness of DDT- as a substitute for rotenone in com- bating the tuber flea beetle, (2) the extent of tuber injury caused by the 11-spotted cucumber beetle, and (3) the effectiveness of undiluted calcium arsenate and various forms of DDT in controlling the 11-spotted beetle. To obtain this information, field plots at Corvallis were treated with: 1. Dust - 0.5 rotenone, 20 percent calcium- arsenate 2. Dust - undiluted calcium arsenate 3. Dust - 3 percent DDT 4« Dust - same as No. 1 plus -bait spray of 10 percent barium fluosilicate and -10 percent brown sugar 5. Dust - same as No. 1 plus bait spray of 1 percent DDT and 10 percent brown sugar Two of M. B. McKay's fields at Corbet, Oreg., were used in a commercial test to" compare 1-1/2 percent DDT dust with 0.5 rotenojie in 20 percent cal- cium arsenate dust. The potatoes grown by Alderman Fa.rms- at Dayton were used to test undiluted 'calcium arsenate and 0.5 rotenone in pure calcium arsenate . As a result of these tests made possible on such a scale by the coopera- tion of these people, Vie can now recommend the use of , DDT on potatoes for the control of the tuber flea beetle (Oreg. Exp. Sta. Cir, of Inf. #227) ^ The undiluted calcium arsenate or the straight calcium arsenate plus 0.5 rotenone will also control the tuber flea beetle and are effective to a lesser 1 extent than 3 percent DDT dust on the 11-spotted cucumber beetle., Atomized' oil con- taining 5 percent DDT is also effective in controlling both the" flea' beetle and the spotted beetle. The bait spray of DDT was more effective than that containing the fluosilicate. There can be no doubt that the larvae of the 11-spotted cucumber beetle cause injury to potato tubers. The injury is very similar to and in many instances just as severe as that caused by the tuber flea beetle. Further investigation must be conducted to determine the correct timing of dust applications for the control of this pest. K. W. Gray and Joe Schuh CARROT RUST FLY. — An experiment at Woodburn, Oreg., in April, consisted of 6 treatments and 5 replicates on 30 randomized plots of carrots, each 100 feet of row. One application of 3 percent Oesarol A- 3 (Geigy Co.) was applied by knapsack duster at rate of 1/2 pound to 100-foot row. Carrots were just showing through the soil and flies were present in the field. Reduction of injury was highly significant. Checks showing 55 percent wormy carrots compared to 12 percent wormy carrots in DDT plots. H. E. Morrison Symphylid — Experiment at Corvallis in May involved three vegetable garden plots of 17 square feet, and six l/lO-acre bean plots. In the garden plots, 3 percent Gesarol A-3 dust (Geigy Co.) was broadcast and rototilled in the soil at rate of 150, 220, and 370 pounds per acre. In the bean plots, 1/4 pound of the dust and 5 ounces of seed per 40 feet of row were drilled in the soil with a small hand seeder. Results were as follows: Vegetable garden- — no appreciable reduction in population or reduc- tion in injury to plants. '\ : Bean plots — overall reduction in population of 97 percent on the DDT plots over the check. A corresponding increase in yield and reduction in root injury. Soil-Seed treatment of carrots — percent injury . i 2 3 : 4 ■ r 5 : 6 : Total : Av. Insecticide 1. : : : ! 4 : 2 • : 2 : 8 I 1.3 • DDT 2. : 10 10 8 : 18 14 : 8 : 68 \ 11.3 : Halowax 3.' : 4 : 6 : 6 • 10 ■ 24 : 22 • t 72 : 12.0 : Naph-Sulfur 4.: ' 8 , 16 ! 8 ! 26 : 12 : 4 : t 74 • 12.3 Dichloroethyl ether 5.' - 16 - 10 ! 36 : 11 ! 32 : 16 - 121 20.2 : Check DDT Dusted — 6 percent injury H. E. Morrison Psallus ancorifer Fieber (An onion seed plant bug) . — In early July in the Willamette Valley, Gesarol A-3 dust (Geigy Co.) was applied with a bellows hand type duster at rate of 35 pounds per acre to a 25- by 50-foot plot of onions raised for seed. An infestation of 25 to 75 bugs per seed head was counted before the dust was applied. Forty-eight hours after dust was anplied there were no live bugs in the dusted block. A number of dead bugs were found down deep in some of the heads. The infestation in the remainder of the field aopeared to be the same as on the date the dust was applied to the test plot — 25 to 75 bugs per head — except for a few rows just east of the experimental plot. In these rows there were very few live bugs and a number of dead ones. B. G. Thompson VARIOUS VEGETABLE INSECTS. — At Corvallis, strawberries, asparagus, musk- melons, mangels, onions, kale, broccoli, cabbage, eggplant squash, cucumber, soybeans (Bansii) , peas, lettuce, turnips, tomatoes, carrots, beets, corn, beans, lima beans, and potatoes — 1/4 acre — were treated for control of po- tato flea beetle ( Epitrix spp.) , cabbage flea beetles ( Phyllotreta spp.), 11-spotted beetle, onion thrips, cabbage maggot and aphids, pea weevil, bean aphid, and nitidulid. Eight applications of 5 percent DDT in light summer spray oil — average about l/2 gallon per acre — were made by hand atomizer from June 6 to August 1* All insects appeared to be controlled except anhids on cole crops and beans, and the cabbage maggots. The two-spotted mites increased in numbers. This was the nearest insect-free garden until the mites moved in. There was definite burn on soybeans (Bansii) probably due to the oil. The kale was fed to chickens from June throughout the summer, and. it is still being fed, with no apparent ill effects. All vegetables were consumed by the family and others, with no ill effects. The only residue analysis was on the .beans (Blue Lake) at time they were canned. The residue was 1.87 milligrams DDT per pound or 0.029 grains per pound. K. W. Gray Berry Insects OBLIQUE-BANDED LEAF ROLLER. —At Gresham, 0reg.,_ small plots and field tests involving some 250 acres of raspberries gave practically 99-percent control of oblique-banded leaf roller with no apparent damage to bees or other bene- ficial insects. Insecticides tested were as follows: (1.) 1-1/2 percent "DDT" dust, one application 2 weeks before blossoming period. (2.) Gesarol A -20, 2 pounds per 100 gallons, one application 2 weeks before blossoming period. (3») 5 percent "DDT" in oil at ratio of 2 quarts per 100 gal- lons. One application 2 weeks before blossoming period. K. W. Gray and Joe Schuh Fruit Insects CHERRY FRUIT FLY. — In June at Corvallis one plot of about 25 cherry trees and a second plot of 8 scattered trees (isolated) were treated with 2 percent and 3 percent DDT dusts with sulfur, talc, and diatomaceous earth as diluents, used at the rate of 40 pounds to the acre — probably about 50 trees to the acre. Application was with a power duster. Results insofar as available: : ' A. 2 percent dust - 2,476 cherries were examined and 3,356 larvae found, B. 3 percent dust (isolated orchard) - 3,452 cherries examined and 1,089 larvae were found. S. C. Jones PEAR THRIPS. — Gesarol A-20, 2# and 1#, with. 2 pounds whale oil soap in each, to 100 gallons of spray; also Gesarol SH 5 (Geigy,Co.) at the rate of 1 quart and 2 quarts to 100 gallons of spray, using from 4 to 5 gallons per tree, were applied in March with a power sprayer to 24-30 prune trees in each of 4 plots at Corvallis against adult pear thrips. Based on the mortality of thrips in the buds 6 to 8 hours after spraying, heavy mortality in all of the DDT plots. Numerous live thrips were found in DDT plots 2 to 6 days after spraying. With a power duster, 2 percent and 3 percent DDT with sulfur, talc, and diatomaceous earth, were applied at rate of 35 pounds per acre to 2 plots of about 100 prune trees per plot at Dallas. Application was made in May, at, the beginning 'of shuck fall, against pear thrios larvae. Thrips population on 300 leaves before dusting was 194. One day after dusting there were 28 on the foliage, and only 5 of these were still alive, where 3 percent dust was used. With the 2 percent dust, on 300 leaves, 133 larvae were found before dusting, and the day after dusting only 40 larvae were found on the foliage, and all of them were dead except 9« Adjoining check plots showed 127 and 139 larvae per 300 leaves a day after dusting. Of this number, 3 and 8 larvae, respectively, were dead. At Corvallis, 16 plots of prunes, 9 square feet each way — 8 treated and 8 untreated adjacent — were used to test 5 percent DDT in oil (Gesapon 18) varied from 1 quart to 1 gallon in 100 gallons of spray, applied on soil with a sprinkling can in March to control pear thrips. Only 2 adults emerged from the treated plots, while over 1,000 adult thrips emerged from.the adjacent untreated plots. . w ■ v S. C« Jones PEACH TOG BORER (Anrrsia lineatella Zell.) .—At Corvallis on May 12, Gesarol A-20 at the rate of 2 pc'u ids in 100 gallons of water was applied by power sprayer to one apricot tree. A~ricots were about l/2 inch .in diameter. Some of the apricots which were already falling from the tree were infected with live larvae. The owner reported that the apricots from the tree were always wormy. This year the owner reports that at harvest he didn't find a single apricot with a live worm in it. A few had dead worms in the cots. There was no apparent injury to the tree, the spray operator, nor to those who con- sumed the apricots. The owner is very enthusiastic over the results. S. C. Jones Nut Insects FILBERT WORM. — In July, treatments were applied with power duster and power sprayer to 3 filbert orchards in the Willamette Valley, The form and dosage of DDT was as follows: Gesarol A-3 dust and A 20, 2 pounds in 100 gallons of spray. Rate 65 pounds per acre — 70-96 trees — 10-12 gallons per tree. Results were favorable, but slightly less effective than lead arsenate. Infestation in nuts was slightly more than in the lead arsenate check. Cnephasia longana (Haw.). — Gesarol A-3 dust, applied in May with a hand duster to 120 newly planted filbert trees (1-1/2 acres) in the Willamette Valley, gave practically 100-percent control. B. G. Thompson