RESERVE. -7'/WjS',3'. tfS 
 
 CONNECTICUT 
 
 Agricultural Experiment Station 
 
 NEW HAVEN, CONN. 
 BULLETIN 195, JULY, 1917 
 
 ENTOMOLOGICAL SERIES, No. 24. 
 
 INSECTS INJURING STORED FOOD PRODUCTS 
 IN CONNECTICUT 
 
 By W. E. BRITTON, State Entomologist. 
 
 Figure i. Ear of corn injured by the European grain moth, half natural 
 
 size. 
 
 CONTENTS. 
 
 Officers and Staff of Station 2 
 
 Insects Injuring Stored Food Products 
 
 in Connecticut 3 
 
 The Grain Beetles 3 
 
 Common Meal Worm 3 
 
 Darker Meal Worm 4 
 
 Cadelle 4 
 
 Pea Weevil 5 
 
 Common Bean Weevil 6 
 
 Four-Spotted Bean Weevil 7 
 
 Drug Store Beetle 7 
 
 Confused and Rust-Red Flour Beetles. 8 
 
 Saw-toothed Grain Beetle 8 
 
 Granary Weevil g 
 
 Rice Weevil g 
 
 The Flour and Meal Moths 10 
 
 Indian Meal Moth 10 
 
 Mediterranean Flour Moth 
 
 Meal Snout Moth 
 
 The Grain Moths 
 
 Angoumois Grain Moth 
 
 European Grain Moth 
 
 Other Insects Occasionally Attacking 
 
 Foods 
 
 Control Methods 
 
 Temperature 
 
 Heat 
 
 Cold 
 
 Air-Slaked Lime 
 
 Pest-proof Packages 
 
 Fumigation 
 
 Carbon Disulphide 
 
 Hydrocyanic Acid Gas 
 
 Summary 
 
 The Bulletins of this Station are mailed free to citizens of Con- 
 necticut who apply for them, and to others as far as the editions 
 permit. 
 
CONNECTICUT AGRICULTURAL EXPERIMENT STATION. 
 
 OFFICERS AND STAFF. 
 
 BOARD OF CONTROL. 
 His Excellency, Marcus H. Holcomb, ex-officio, President. 
 
 James H. Webb, Vice President 1 [amden 
 
 George A. Hopson, Secretary Walling ford 
 
 E. H. Jenkins, Director and Treasurer New 1 taven 
 
 Joseph W. Alsop \von 
 
 Wilson H. Lee Orange 
 
 Frank H. Stadtmueller Elmwood 
 
 Administration. E. H. Jenkins, Ph.D., Director and Treasurer. 
 
 Miss V. E. Cole, Librarian and Stenographer. 
 Miss L. M. Brautleciit, Bookkeeper and Stenographer. 
 William Veitcii, In charge of Buildings and Grounds. 
 
 Chemistry. 
 
 Analytical Laboratory. John Phillips Street, M.S., Chemist in Charge. 
 E. Monroe Bailey, Ph.D., j 
 
 C. B. Morison, B.S., C. E. Shepherd, Assistants. 
 
 W. L. Adams, B S. 
 
 Hugo I-ange, Laboratory Helper. 
 
 V. L. Churchill, Sampling Agent. 
 
 Proteid Research. T. B. Osborne, Ph.D., D.Sc, Chemist in Charge. 
 
 Miss E. L. Ferry, M.S., Assistant. 
 
 Botany. G. P. Clinton, Sc.D., Botanist. 
 
 E. M. Stoddard, B.S., Assistant Botanist. 
 Florence A. McCormick, Ph.D., Scientific Assistant 
 G. E. Graham, General Assistant. 
 
 Entomology. W. E. Britton, Ph.D., Entomologist; State Entonv I 
 
 B. H. Walden, B.Agr., First Assistant. 
 
 Q. S. Lowry, B.Sc, 1. W. Davis. B.Sc, I , 
 
 n,r t> t t> o , Assistants. 
 
 M. P. Zappe, B.S.. » 
 
 Miss G. A. Foote, B.A., Stenographer. 
 
 Forestry. Walter O. Filley, Forester; also Stale Forester 
 
 and Stale l-'fics! Fire Warden. 
 A. K. Moss, M.F., Assistant State and Station Forester. 
 M iss E. I ,. A\ im . $ tenogt apher. 
 
 Plant Breeding. Donald F. Jones, M.S.. Plant Breeder. 
 
 C. D. Hubbell, Assistant. 
 
 Vegetable Growing. . 
 
Insects Injuring Stored Food Products in Connecticut. 
 
 By W. E. Britton, State Entomologist. 
 
 The importance of growing more food for the people of this 
 country cannot be over-emphasized, and the various efforts along 
 this line and the publications giving information regarding 
 methods are all praiseworthy. Nevertheless, it is perhaps equally 
 important to conserve the food supplies already grown and 
 stored. It has been estimated that insects take an annual toll 
 of about five per cent of the value of the stored food products, 
 amounting to $200,000,000.00 each year, in the United States. 
 Most of this loss is wholly preventable if attention is given the 
 matter at the right time, and there is no time when control 
 methods can be enforced with greater profit to the owner, or with 
 greater benefit to our country and to mankind than the present. 
 
 The object of this bulletin is to place before the people of 
 Connecticut a brief account of the principal insects attacking and 
 injuring stored grains and food products in the state, and to 
 suggest methods of controlling them. The figures are included 
 for the purpose of illustrating the text and of giving an idea 
 of the general appearance of the insects. 
 
 These insects belong in two large natural groups : the Beetles 
 (Coleoptera) and the Moths (Lepidoptera). The principal fea- 
 tures of each are given to enable the reader to identify the 
 species, but as control measures are similar for all, information 
 on this point is given in a separate chapter on page 16 of this 
 bulletin. 
 
 THE GRAIN BEETLES. 
 
 The Common Meal Worm, Tenebrio molitor Linn. 
 
 In and around the bottoms of bins and barrels where corn meal, 
 
 flour, or other cereals are stored, one often finds yellow larvae 
 
 about an inch in length and resembling wire worms. These feed 
 
 upon the meal and are called meal worms. 
 
 The adult is a shining, black or dark brown, beetle, somewhat 
 more than half an inch in length, with thorax rather finely punc- 
 tured and wing-covers longitudinally striated or grooved. The 
 
4 CONNECTICUT EXPERIMENT STATION BULLETIN [95. 
 
 beetle lays its white eggs in the meal, usually in masses, with a 
 juice or sticky material which causes the meal to adhere to the 
 eggs. The eggs hatch in about two weeks and the larvae feed 
 upon the meal for three months or longer before pupating. The 
 pupal stage requires about two weeks, and normally there seems 
 
 Figure 2. Common meal worm, adult and larva, natural <ize. 
 
 to be but one generation each year. The adults mostly emerge 
 in the spring, but where the meal is stored in the house, or in a 
 heated building, they may appear at any time of the year. This 
 insect is shown in figure 2. 
 
 The Darker Meal Worm, Tenebrio obscurus Fabr. 
 
 This insect is much like the preceding except that the larvae 
 are darker in color and the adult beetles are dull instead of shiny. 
 The life history and injuries are similar and both often occur in 
 the same place. 
 
 The treatment is also the same for both species, viz. ; fumi- 
 gating with carbon disulphide or heating the meal in an men for 
 a short time. 
 
 The Cadelle, Tenebrioides mauritanicus Linn. 
 
 The larva of this beetle is dirty-white, with head, prothorax 
 and tip of abdomen dark brown, and when fully grown it meas- 
 ures about three-fourths of an inch in length. It ha- the habit 
 of tunneling into wood to make its cocoon, at least when sofl 
 pine is available! The pupa stage evidently lasts three or four 
 weeks. 
 
 The adult beetle is brown ami shiny, and about three-eighths of 
 an inch long. It lays while eggs which are ;i trifle over a milli- 
 meter Ion" and one-fourth as thick. 
 
THE PEA WEEVIL. 
 
 5 
 
 There is a single generation annually, and the cadelle feeds on 
 various kinds of stored foods and plant products and is also 
 partially predaceous, as Chittenden* states that both larvae and 
 adults attack and destroy other grain insects which they 
 encounter. Nevertheless, the cadelle is capable of causing con- 
 
 Figure 3. Cadelle, adult and larva, twice natural size. 
 
 siderable injury and the treatment is the same as for the other 
 meal worms. The larvae of the cadelle have been reported from 
 many unexpected places, such as in sugar, in bottles of milk, 
 in powdered hellebore, and boring through the parchment paper 
 of jars of jams and jellies. In some of these places they 
 probably occurred accidentally. Larva and adult are shown in 
 figure 3. 
 
 The Pea Weevil, Bruchus pisorum Linn. 
 The adult beetle is about one-fifth of an inch long, and the 
 wing covers are marked with small black and white spots. It 
 lays eggs singly on the outside of the green pods in the field, 
 and the larva tunnels through the pods and into one of the green 
 peas. The insect does not mature until the peas have ripened 
 and have been harvested and placed in storage. Then it is com- 
 mon to find a single round hole in a pea where the adult has 
 emerged. Sometimes nearly every pea has a hole in it, and 
 many larvae are unquestionably cooked and eaten in green peas ; 
 
 * F. H. Chittenden, Farmer's Bulletin No. 45, U. S. Department of 
 Agriculture, page 19, 1896. 
 
6 CONNECTICUT EXPERIMENT STATION BULLETIN 1 95. 
 
 but the insect does not g'o on breeding" in dry stored peas, there 
 being- only one brood each year. 
 
 The pea weevil is more serious in the .Middle Atlantic than in 
 the Northern States, but it is present in Connecticut. In the 
 Southern States it is claimed that late planting brings compara- 
 
 Figure 4. Pea weevil, adult beetle, four times enlarged. 
 
 tive immunity from attack but in the writer's experience late 
 planted peas seldom produce a satisfactory crop here. Hence it 
 is better to treat the seed soon after harvesting, and to make 
 allowance in planting for a certain percentage of injured seed. 
 This insect is shown in figure 4. 
 
 The Common Bean Weevil, Bruchus obtectus Say. 
 This is probably the greatest enemy of beans in Connecticut. 
 and though in size somewhat smaller than the pea weevil and 
 
 Figure 5. Common bean wee- 
 vil. Adult beetles, four times 
 enlarged. 
 
 
 
 Figure 6. Infested cow pea-. 
 showing eggs and exil holes oi 
 bean weevil, natural size. 
 
THE DRUG STORE BEETLE. 7 
 
 resembling it in color and markings, it differs from it by con- 
 tinuing to breed in the dry, stored seed. There are six genera- 
 tions annually in the District of Columbia, and a smaller number 
 in the northern states. Stored beans are often entirely destroyed, 
 or at least rendered unfit for planting, or as food for man or 
 beast. The beans often have several holes in each where the 
 adults have emerged, and as many as 28 have been found in a 
 single seed. Severely weeviled beans are almost useless for 
 planting, but the good seed may be separated from the infested 
 seed by throwing into water. The injured seed will float and 
 may be discarded. This beetle and its work are shown in 
 figures 5 and 6. 
 
 The Four-Spotted Bean Weevil, Britclius quadrimaculatus 
 
 Fabr. 
 This species is somewhat more slender than the preceding and 
 has different markings. Its habits and life history are similar 
 and the same control methods may be practiced. 
 
 The Drug Store Beetle, Sitodrepa panic ea Linn. 
 
 Of all the insects attacking stored food products, perhaps none 
 is more cosmopolitan or feeds upon a greater number of different 
 kinds than the drug store beetle. It is a common pest of all 
 kinds of stored vegetable foods and may be found in breakfast 
 
 Figure 7. Drug store beetle. Adults, four times enlarged. 
 
 foods, or the dried roots, stems, bark, and seed capsules com- 
 monly called spices. It feeds also on the parts of plants used as 
 drugs, often eating those which are bitter and poisonous to man, 
 It has been recorded as attacking forty-five different drugs. It 
 is now distributed throughout the civilized world, and four or 
 
8 
 
 CONNECTICUT EXPERIMENT STATION BULLETIN 1 95. 
 
 five generations may occur in a year, especially in a heated 
 building. 
 
 The beetle is about one-tenth of an inch in length, covered 
 with a silky pubescence, and reddish-brown in color. The wing- 
 covers are longitudinally striated and the antennae terminate in 
 three long segments forming the so-called "club." The larvae 
 are white, with dark mouth parts, and assume a curved attitude 
 when at work in their burrows. The adult is shown in figure 7. 
 
 The Confused Flour Beetle, Tribolium confusum Duv. and 
 The Rust-red Flour Beetle, Tribolium ferrugineum Fabr. 
 
 The confused flour beetle has been known to occur in this 
 country for nearly twenty-five years and has caused injury 
 throughout the land. It attacks seeds, stored cereals and other 
 starchy foods and drugs, and is a pest in flour and grain mills. 
 
 The adult is a flattened brown beetle, less than a sixth of an 
 inch in length. There may be as many as four generations 
 annually in a heated storehouse. 
 
 The rust red flour beetle closely resembles the preceding, but 
 is not nearly as common in Connecticut. It is a pest in the 
 Southern States and is often shipped north in rice or other 
 starchy food products. 
 
 The Saw-toothed Grain Beetle, Silvanus surinamensis Linn. 
 
 One of the most common beetles in grain and stored food 
 products is the saw-toothed grain beetle. It is less than an* eighth 
 of an inch lon°\ flattened, sfrooved longitudinally, with teeth- 
 
 Figure 8. Saw-toothed grain beetle Eour times enlarged. 
 
 like projections on tin- sides oi the thorax, ami brown in color. 
 The larva is white, extremely active, and makes its pupa case on 
 some convenient surface by joining together panicles oi the 
 infested material with some adhesive substance which it secretes. 
 
THE GRANARY WEEVIL. 9 
 
 There are probably four or five generations each year, and the 
 beetles eat through paper bags and pasteboard boxes to reach 
 foodstuffs inside. Though perhaps preferring farinaceous 
 foods, this beetle often infests fruits and almost all kinds of 
 stored food products. This beetle and its injury to corn are 
 shown in figures 8 and 9. 
 
 Figure 9. Peruvian seed corn injured by saw-toothed grain beetle, 
 
 reduced one-half. 
 
 A flat, smooth, reddish-brown beetle, still smaller than the pre- 
 ceding, is occasionally found infesting wheat bran or other 
 cereals. This is Lcemophlceus pusillus Schr., one of the minor 
 pests but nevertheless capable of causing much injury. 
 
 The Granary Weevil, Calandra granaria Linn. 
 Both this weevil and the following belong to the family Calan- 
 dridae or snout beetles. The adult is a shiny reddish-brown 
 snout beetle nearly an eighth of an inch in length, with a long 
 proboscis. The larva is a legless grub. Both adult and larva 
 feed upon the kernels of the grain. There are four or five 
 generations each year in the vicinity of Washington, D. C, and 
 more farther south. It attacks and injures maize and all of the 
 small grains. 
 
 The Rice Weevil, Calandra orysae Linn. 
 
 This species resembles the preceding except that it is dull 
 
 brown instead of shining, and the thorax is more densely pitted. 
 
 There are four more or less distinct red spots on the wing-covers. 
 
 This insect is often found in the field and takes its name from 
 
TO CONNECTICUT EXPERIMENT STATION BULLETIN 1 95. 
 
 the rice which it infests. Its habits and life history are otherwise 
 similar to the preceding. It is shown in figure 10. 
 
 Figure 10. Rice weevil. Adults four times enlarged. 
 
 THE FLOUR AND MEAL MOTHS. 
 The Indian Meal Moth, Ploclia interpunctella Hubn. 
 Considerable damage is done each year in mills, granaries, seed 
 warehouses, etc., by the Indian meal moth, which is also a com- 
 mon pest of the household, as it attacks nearly all kinds of 
 
 FIGURE ii. Kernels uf corn injured by the Indian meal moth. Natural 
 
 size. 
 
THE MEDITERRANEAN FLOUR MOTH. H 
 
 vegetable food products. Each year some food material infested 
 by this insect is brought to the writer's attention. In 1905 some 
 large seed warehouses near New Haven were found infested, 
 and one room was fumigated with hydrocyanic acid gas. This 
 treatment killed the larvae crawling about, and those at work 
 near the outside of the bags, and at first seemed to be effective. 
 Later, however, living larvae appeared from inside, showing that 
 the gas did not penetrate far into the mass of grain. 
 
 The larvae web together the grain and flour, especially around 
 the outside. One 100-pound bag of corn was emptied and seven 
 pounds adhered to the bag. The kernels were eaten at the 
 embryo, and are shown in figure 11. 
 
 The eggs are small, white, and laid singly or in groups, and 
 each female may lay as many as 350. The larva is whitish, and 
 spins a silk thread wherever it feeds and travels, and the web 
 
 Figure 12. Indian meal moth, a, adult; b, pupa; c, larva, side view; 
 d, head of larva, front view; e, first abdominal segment of larva; f, 
 larva, dorsal view — all greatly enlarged. (After Chittenden, Bur. of Ent., 
 U. S. Dept. of Agriculture.) 
 
 holds together the particles of food material. Pupation takes 
 place in a silken cocoon-like web from which the moths emerge. 
 From four to five weeks only are required for a generation to 
 develop. In a heated building this insect will breed throughout 
 the year. 
 
 The adult is a small moth having a wing-spread of about five- 
 eighths of an inch; forewings whitish at base with distal half 
 reddish-brown, as shown in figure 12. 
 
 The Mediterranean Flour Moth, Ephestia kuehniella Zell. 
 
 This insect is regarded by Chittenden as the most important 
 
 of all the species infesting flour and grain mills. It has been 
 
12 CONNECTICUT EXPERIMENT STATION BULLETIN 195. 
 
 reared from flour in New Haven and has been taken at Bran ford. 
 In life history and injury the Mediterranean flour moth resembles 
 the Indian meal moth, and in heated buildings five or six broods 
 mav occur each vear. The moth is shown in figure 1 ^. It is 
 
 Figure 13. Mediterranean flour moth and cocoons, slightly enlarged. 
 
 larger than the Indian meal moth and has a wing-spread of about 
 an inch. The forewings are dull lead-gray, crossed by zigzag 
 darker lines or bands. Not only does this insect injure flour and 
 grain but also feeds upon almost any kind of stored vegetable 
 food products. 
 
 The Meal Snout Moth, PyraMs farinalis Linn. 
 
 This insect infests flour, meal, and other stored food products, 
 though not as serious a pest as the Indian meal moth or the 
 Mediterranean flour moth. 
 
 The larvae have the habit of constructing long tubes by bind- 
 ing together with silk small particles of the meal or food material. 
 In these tubes the larvae live and hide until fullv grown when 
 
 Figure 14. Meal snout moth. Natural size. 
 
 they leave the tubes and spin their cocoons, usually in or just 
 outside of the infested material. There are probably three or 
 four generations each year, though further studies are needed in 
 this latitude to determine this point. 
 
THE ANGOUMOIS GRAIN MOTH. 
 
 13 
 
 The adult has a wing-spread of about an inch, is light brown, 
 with thorax, base and apex of fore wings darker brown, and with 
 whitish wavy lines crossing front and rear wings, as shown in 
 figure 14. 
 
 THE GRAIN MOTHS. 
 The Angoumois Grain Moth, Sitotroga cerealella Oliv. 
 This destructive insect was known in France nearly two hun- 
 dred years ago, and was somehow brought to this country in 
 the early colonial days, and became established in North Carolina 
 and Virginia. Since then it has spread northward to Massa- 
 chusetts, New York and Michigan and throughout the southern 
 states, where it does much damage. The writer first noticed it 
 in Connecticut nearly twenty years ago, and has run across it a 
 number of times since. It is primarily a pest of stored grains, 
 especially corn on the ear, which if infested soon appears as in 
 
 Figure 15. Pop corn showing exit holes of Angoumois grain moth. 
 
 Natural size. 
 
 figure 15. The emerging moths leave small circular holes in the 
 kernels. Infested grain is injured not only for seed, but also 
 for feeding purposes ; as it has been estimated that it loses within 
 six months 40 per cent of its weight and 75 per cent of the 
 starchy matter. The moth lays whitish eggs on the kernels of 
 corn, and they soon turn to a pale reddish color and hatch in 
 five or six days. Two or more larvae may occupy a single kernel 
 of maize, though only one occurs in a grain of wheat. The 
 adult is a light, grayish-brown moth, having a wing-expanse of 
 about half an inch, somewhat resembling a clothes moth. Out 
 of doors in the southern states there are at least four broods 
 
*4 
 
 CONNECTICUT EXPERIMENT STATION BULLETIN 1 95. 
 
 annually and the larva passes the winter in kernels of grain. In 
 this climate it breeds only in stored grain, and in heated buildings 
 this goes on continuously, there probably being five or six genera- 
 tions, depending upon the temperature. 
 
 The European Grain Moth, Tinea granella Linn. 
 
 Compared with the Angoumois grain moth this moth is of 
 secondary importance, and seems to be not especially destructive 
 in the United States. It infests all kinds of cereals, and as each 
 larva may pass from one kernel into another, webbing them 
 together until twenty or thirty grains are spoiled, it is apparent 
 that considerable injury must result. 
 
 Figure 16. European grain moth. Three times enlarged. 
 
 This moth was first found in Connecticut, in 1006.* in a seed 
 warehouse in Milford. It is now distributed throughout the 
 northern states. 
 
 The adult is a slender moth with a wing-spread of half an 
 inch, creamy white mottled with brown, and is shown in figure 
 16. Its work is shown in figure 1. 
 
 OTHER INSECTS OCCASIONALLY ATTACKING 
 FOODS. 
 
 The large cabinet beetle, Trogoderma tarsals Melsh., fre- 
 quently injuries seeds and is shown in figure 17. The small 
 cabinet beetle, Anthrenus verbasci Linn., and the black carpel 
 beetle, Attagenus picens Oliv., occasionally attack and injure 
 food products, though the latter is a more important pesl of 
 clothingr. 
 
 * Report of this Station l~<>r 190(1, page 305. 
 
OTHER INSECTS INJURING FOODS. 
 
 IS 
 
 The larder or bacon beetle, Dermestes lardarius Linn., the red- 
 legged ham beetle, Necrobia rufipes Fabr., and certain species 
 of mites of the genus Tyroglyphits sometimes injure dried meats, 
 cheese, dried fruits, cereals, etc. The cigarette beetle, Lasio- 
 derma serricorne Fabr., though primarily a pest of tobacco, feeds 
 
 Figure 17. Seeds injured by the large cabinet beetle. Natural size. 
 
 upon the spices, rice, figs and many other food products. Then 
 the cheese skipper, Piophila casei Linn., which occurs every- 
 where, often attacks cheese and the larvae may be found tun- 
 neling in it. Cheese should be kept covered and should be 
 examined every day in warm weather. Hams and other kinds 
 of meat are infested only in certain portions which can be cut 
 off and the remainder used for food. 
 
 A species of book-lice, Troctes divinatorius Mull, (order Cor- 
 rodentia), was found eating corn at the Station in 1900. The 
 sample was stored in a ground glass-stoppered jar. The outer 
 surface of the kernels was wholly eaten off, so as to render the 
 variety wholly unrecognizable. 
 
 Cockroaches and ants are also frequently injurious in pantries 
 and storehouses. The former are usually susceptible to the 
 influence of powdered borax, and ants can usually be driven away 
 by scattering naphthalene flakes about on the floor and shelves, 
 especially where the ants have their runways. 
 
 The other insects mentioned in this chapter without control 
 methods may be killed by heat or by fumigation. 
 
l6 CONNECTICUT EXPERIMENT STATION BULLETIN I95. 
 
 CONTROL METHODS. 
 
 The chief methods for preventing damage by the insects men- 
 tioned in the foregoing pages are : the use of high and low- 
 temperature, air-slaked lime, pest proof packages and fumigation. 
 
 Temperature. 
 Temperature is recognized as an important factor in insect 
 development, and often determines in a measure the number of 
 annual generations of certain species. Extremes in temperature 
 are sometimes employed for the control of insects. 
 
 heat. 
 
 It has long been known that heat will kill insects, and one of 
 the simplest methods of destroying them in small packages of 
 flour or other food products is to heat it in the oven for an hour 
 or so. Following this idea Professor George A. Dean started 
 some experiments in Kansas in 1910 to determine the fatal high 
 temperatures for certain grain-infesting insects, and found that 
 few insects can withstand a temperature of from Ii8°-I25° F. 
 for any length of time. In a mill there are accumulations of 
 meal and flour on the floor, beams, machinery, and in the corners 
 everywhere in which insects can breed. To keep a mill free 
 from this accumulation and absolutely clean is almost an impos- 
 sibility. By the use of heat, however, the insects can be killed 
 from time to time without serious inconvenience, without shut- 
 ting down the mill, and without great expense. It requires extra 
 steam pipes sufficient to raise the temperature to about 120° F., 
 and to keep it there for a period of five or six hours to allow the 
 heat to penetrate the bins and bags of grain. Professor Dean has 
 published three papers on this subject,* and any one interested 
 should write to him for further advice. 
 
 Any grain or seeds which are intended for planting should not 
 be heated to a point much greater than 130 F. as there is danger 
 of injuring the vitality, which with some seeds ceases if the 
 temperature approaches 150 F. 
 
 Any product to be used for food will not be injured by this 
 
 * Journal of Economic Entomology. Vol. IV. page 14-'. 191 1; Vol. VI. 
 page 40. 1913. Kansas Agricultural Experiment Station, Bull. 189. July. 
 I9I3- 
 
CONTROL METHODS. 
 
 n 
 
 heating method and even the eggs and larvae, as well as the adult 
 insects, are killed by it. 
 
 COLD. 
 
 A low temperature is not so frequently used for destroying 
 insects, yet it has been known for a long time that insect develop- 
 ment is arrested or suspended altogether in cold storage. 
 
 Mr. J. A. Manter* of Storrs, Conn., states that the bean 
 weevil will not breed in cold storage and suggests that beans be 
 stored in unheated buildings. This idea may be carried out in 
 practice with certain other stored food insects but the exact 
 temperatures have not yet been determined for all species. 
 
 Air Slaked Lime. 
 A very simple and promising treatment to prevent weevil 
 injury to peas, beans, cow peas and possibly to other kinds of 
 
 Figure 18. Effect of air slaked lime. Treated seeds at right. (After 
 Metcalf, North Carolina Agricultural Experiment Station. Jour. Econ. 
 Ent., Vol. 10, plate 3, fig. 2.) 
 
 Journal of Economic Entomology, Vol. X, page 193, 1917. 
 
l8 CONNECTICUT EXPERIMENT STATION BULLETIN 195. 
 
 seeds has recently been discovered by Mr. X. P. Metcalf* of 
 the North Carolina Station. This consists of applying air-slaked 
 lime to the seeds, using one part by weight of lime to two parts 
 of seeds when placing the crop in storage. For small quantities, 
 say less than a half peck, Professor Metcalf advises the writer 
 in a letter that four parts of lime should be used to one part of 
 seeds ; for quantities between a half peck and three bushels, use 
 equal amounts of lime and seeds. The quantity of seeds to be 
 stored thus influences the effectiveness of the treatment and 
 •necessitates greater proportions of lime for small quantities. In 
 time this method may be found applicable to other kinds of seeds 
 and against other insects. It has the advantage of being harm- 
 less to seeds and to the operator, as well as being convenient to 
 procure and relatively inexpensive. Professor Metcalf is now- 
 completing further tests of this material. Figure 18 shows 
 untreated seeds and those treated with lime. 
 
 Pest-proof Packages. 
 
 Materials sealed in glass or metal containers are usually safe 
 against insects as long as they remain unopened. We have a 
 number of records showing that the smaller beetles, like the saw- 
 toothed grain beetle, will enter poorly stoppered glass bottles and 
 jars and even tin-stoppered cans. The material is of course 
 often infested before placing in the containers. 
 
 Mr. William B. Parker of the U. S. Bureau of Entomology 
 has made investigations and suggestsf a sealed paper carton, for 
 packing cereals which are to be placed upon the market. While 
 this may prevent infestation in stores and warehouses, in the 
 household many opened packages often attract insects, and if 
 stored for a long time no paper package is insect-proof. Hence 
 other methods must be resorted to, especially in dwelling houses, 
 to keep the foodstuffs free from insect attack. 
 
 FuM [GATI0N. 
 Fumigation has long been practiced to kill insects in seeds and 
 food substances. For this purpose two materials are commonly 
 used, viz., carbon disulphide and hydrocyanic acid gas, 
 
 * Journal of Economic Entomology, Vol. X. page 74, 1017. 
 f Bulletin 15, U. S. Department of Agriculture, 1913. 
 
CONTROL METHODS. I 9 
 
 CARBON BISULPHIDE (BISULPHIDE) . 
 
 This is a colorless, ill-odored liquid which volatilizes at air 
 temperatures, more readily in warm weather, and the fumes are 
 deadly to all forms of insect life. Carbon disulphide may be 
 purchased in pound bottles from any wholesale druggist, and as 
 it is inflammable when the fumes are mixed with air, it should 
 not be used by any one smoking, or at night with oil or gas lights 
 near. As the fumes are heavier than air the liquid should be 
 placed on top, rather than at the bottom of the grain, seeds or 
 material to be treated. It should also be placed in a shallow dish 
 to facilitate volatilization. The quantities used are about one 
 pound to each 40 bushels of seeds, or to each 100 cubic feet of 
 space. In a tight barrel containing grain or seeds, about one- 
 half cupful of the liquid should be placed in a saucer on top of 
 the seeds, the barrel covered tightly and allowed to remain all 
 day or longer. For smaller receptacles, use proportionate quan- 
 tities of the liquid. Carbon disulphide is more convenient, less 
 dangerous to the operator, and its fumes penetrate better than 
 hydrocyanic acid gas. A recent bulletin by Dr. Hinds* contains 
 much information about carbon disulphide and may be obtained 
 by applying to the U. S. Department of Agriculture, 
 Washington, D. C. 
 
 HYDROCYANIC ACID GAS. 
 
 This is a deadly poisonous gas generated by putting together 
 cyanide, sulphuric acid and water. Potassium cyanide was for- 
 merly recommended, but sodium cyanide is now the cyanide of 
 commerce and is effective. The quantities for 100 cubic feet of 
 space are as follows : — 
 
 Sodium cyanide 1 oz. 
 
 Commercial sulphuric acid 2 fluid ozs. 
 
 Water 4 " 
 
 If a room is to be fumigated its cubic space must be ascer- 
 tained and the chemicals carefully weighed or measured. It 
 must be made reasonably tight, and provision must be made for 
 opening from the outside at least one window or door, besides the 
 exit. The generating jar may be earthen or stoneware but never 
 
 * Farmers' Bulletin 799, U. S. Department of Agriculture, June, 1917. 
 
20 CONNECTICUT EXPERIMENT STATION BULLETIN I 95. 
 
 metal. The acid may be diluted with the water, the cyanide 
 placed in a paper or cheesecloth bag, and when all is ready the 
 operator should drop the bag into the jar and with bated breath 
 retire at once and close and lock the door. One full inhalation 
 of this gas will drop a man, and no carelessness should be per- 
 mitted. The house or room should be exposed for at least two 
 hours and may remain closed over night or over Sunday. The 
 fumes do not penetrate as well as those of carbon disulphide. 
 
 Recently Mr. E. R. Sasscer of the U. S. Department of Agri- 
 culture has devised an apparatus for fumigating cotton bales, 
 bags of seeds, etc. By removing the air and forcing the gas 
 into a partial vacuum thus created, most insects are killed with 
 a half hour exposure.* On account of the danger, trouble of 
 generating, etc., the average farmer and householder will seldom 
 use hydrocyanic acid gas and will find carbon disulphide or heat 
 sufficient to meet his needs. 
 
 SUMMARY. 
 
 Much damage results each year in Connecticut to cereals 
 and other stored food products from the attacks of insects. 
 This injury has been estimated at five per cent of the total 
 value of the products, or $200,000,000.00 each year for the 
 United States, and is wholly preventable. 
 
 The insects are chiefly beetles (Coleoptera) and moths 
 (Lepidoptera). The former include the meal worms, cadelle. 
 pea and bean weevils, drug store beetle, confused flour beetle, 
 rust-red flour beetle, saw-toothed grain beetle, granary weevil, 
 rice weevil, large and small cabinet beetles, black carpet beetle, 
 larder beetle, red-legged ham beetle, and cigarette beetle. 
 The latter include the Indian meal moth, Mediterranean flour 
 moth, meal snout moth, Angoumois grain moth, and European 
 grain moth. Other insects like the cheese skipper (a fly), a 
 book louse, ants, cockroaches, and even mites occasionally 
 cause damage. 
 
 The most important of these pests are described briefly in 
 the preceding pages. 
 
 * Bulletin 186, U. S. Department of Agriculture, 1915. 
 
SUMMARY. 2 1 
 
 Most of these insects may be destroyed by raising the 
 temperature to a point between 120 and 130 F. for five or six 
 hours. The vitality of seeds is endangered if the heat 
 approaches 150 F. but the material would not be injured for 
 food. 
 
 Food kept in cold storage will not be injured by insects. 
 
 Various pest proof packages have been devised, but food 
 often becomes infested in them, and no package is pest proof 
 after the seal has been broken. 
 
 Air-slaked lime applied to seeds when placed in storage 
 will prevent most of the damage caused by the pea and bean 
 weevils. The proportions are as follows: For small quanti- 
 ties, say less than a half peck, four parts of lime to one part 
 of seeds ; between a half peck and three bushels, equal parts 
 of lime and seeds ; for greater quantities, one part of lime to 
 two parts of seed. 
 
 Fumigating with carbon disulphide, using a half cupful to 
 a barrel, will rid the material of insect life, This liquid 
 should be placed on top of the infested material, and should 
 not be used near a fire as it is inflammable. The container 
 should be tightly covered for twenty-four hours or longer. 
 
 Hydrocyanic acid gas may also be used but is not advised 
 except in particular cases, as it is deadly to breathe and does 
 not penetrate masses of flour and grain readily. Seeds and 
 food materials if thoroughly aired are not injured by carbon 
 disulphide or hydrocyanic acid gas, either for food or for 
 planting. 
 
 For more detailed information on this subject the reader 
 should refer to the pages of this bulletin. 
 
University of 
 Connecticut 
 
 Libraries 
 
 39153029221647