HOUSEHOLD CIRCULAR 172 APRIL 1951 CALIFORNIA AGRICULTURAL EXTENSION SERVICE THE COLLEGE OF AGRICULTURE • UNIVERSITY OF CALIFORNIA Before using insecticides recommended in this circular, carefully read the instructions on containers. Solutions containing contact insecticides are sometimes inflam- mable and should not be applied near open flames of any kind. For other precautions, see page 6. This circular recommends control measures that can be taken by housewives against insects and related pests commonly found in California homes. Wood-boring insects such as termites and the several species of beetles infesting wood are considered structural pests and are not discussed in this circular. The authors: A. E. Michelbacher is Associate Professor of Entomology and Associate Entomologist in the Experiment Station. Deane P. Furman is Assistant Professor of Parasitology and Assistant Entomologist in the Experiment Station. 11 ^E V I D found in the home can be divided for control pur- poses into two groups: CHEWING INSECTS These include cockroaches, crickets, carpet beetles, pantry insects, ants, wasps, and the larvae of clothes moths. They destroy articles by eating holes in them, or by chewing and consuming the materials they infest. Therefore, stom- ach poisons or fumigants are used to kill them, although many contact in- secticides — especially the newer ones such as DDT, DDD, methoxychlor, chlor- dane, toxaphene, and benzene hexa- chloride — are very effective. SUCKING INSECTS These include mosquitoes, bedbugs, fleas, and body lice. They feed by in- serting their mouthparts through the skin of man or animals and sucking the blood. They are controlled by contact insecticides or fumigants. Some insects such as houseflies have lapping-suck- ing mouthparts that do not pierce skin, but do contaminate food. This group is controlled largely by contact insecti- cides, although stomach poisons may be used effectively. THESE INSECTS and their relatives — the mites, ticks, and spiders — do not always remain in one part of the house, but to aid the housewife in identi- fying pests she does not recognize, most of those discussed in this circular are grouped below according to where they will most likely be encountered. Spiders and those pests that enter homes by accident (including predaceous and darkling ground beetles, corizid grass bugs, and box elder bugs) may be found throughout the house. A complete index is on page 34. IN STORED FOOD PRODUCTS PAGE ON AND NEAR FOOD page Cereal mites 13 Ants 7 Flour moths 19 Cockroaches 15 Meal moths 19 Flies 17 Pantry beetles 23 Psocids 26 ATTACKING HUMANS AND PETS Bedbugs 8 IN FABRICS AND PAPER Brown dog ticks 9 Carpet beetles 10 Fleas 16 Clothes moths 13 Lice 20 Crickets 16 Mosquitoes 21 Psocids 26 Triatoma bugs 29 Silverfish 27 Tropical rat mites 30 [3 InSCCtlCIClCS used in the control of household pests are of three types: 1 . Stomach poisons 2. Fumigants 3. Contact poisons (Many of the newer insecticides, such as DDT, DDD, methoxychlor, benzene hexa- chloride, chlordane, and toxaphene act both as stomach and contact poisons; some also exert a fumigant action.) Stomach poisons. Sodium fluoride, sodium fluosilicate, and sodium arsenite are strictly stomach poisons. They are very active poisons and should be used with a great deal of caution. Sodium fluoride and sodium fluosilicate are used in poison baits and as dusts, sometimes in combination with other materials for the control of such insects as cockroaches, crickets, and ants. Sodium fluosilicate is also used in the preparation of mothproofing solutions. Sodium arsenite, a very toxic material, is used at low con- centrations as the active killing agent in certain commercial ant syrups. Rotenone, an insecticide obtained from a plant source, is relatively nonpoisonous to humans and is primarily a contact insecticide. It has some action as a stomach poison and is effective against a number of household pests. It is available in dust and liquid preparations, and is frequently combined with other insecticides. Fumigants. Those that can be used safely and effectively in the home are paradi- chlorobenzene, naphthalene, a mixture of 3 parts by volume of ethylene dichloride to 1 part of carbon tetrachloride, and carbon tetrachloride. Paradichlorobenzene (PDB) is a clear crystalline material. It can be used to fumigate only materials other than food, for its odor is readily absorbed. Materials to be fumigated are placed in tight containers (such as trunks), and the fumigant crystals scattered throughout the materials or placed between layers of paper. For satisfactory control, infested materials should be subjected to the fumigant vapor for several days at a temperature of not less than 70 degrees F. Longer exposure will do no harm. Naphthalene is a flaky material used in the same manner as paradichlorobenzene. It evaporates more slowly than PDB and therefore requires a longer exposure to infested materials to insure good control. The ethylene dichloride-carbon tetrachloride mixture is a liquid fumigant with an odor similar to that of chloroform. It can be used to fumigate foods as well as other household articles, but it imparts a taste to foods having a high fat or protein content- products of this nature should be thoroughly aired following fumigation. Tight con- tainers should be used, and exposure should be at least 24 hours at 70 degrees F. Avoid breathing the vapors as much as possible. Carbon tetrachloride is a clear liquid fumigant used in the same manner as when mixed with ethylene dichloride. [4] There are many other fumigants, all of which are too hazardous for the housewife to use. These include methyl bromide, hydrocyanic acid, and chloropicrin. If the use of these dangerous fumigants proves necessary the work should be done by a licensed pest control operator. Contact insecticides. These include nicotine, pyrethrum, rotenone, organic thiocy- anates, mineral oils, and some of the newer insecticides such as DDT (dichlorodiphenyl- trichloroethane), DDD (dichlorodiphenyl-dichloroethane), methoxychlor (dianisyl- trichloroethane), benzene hexachloride (666), lindane, chlordane, and toxaphene (chlorinated camphene). These insecticides are available in commercial preparations as concentrated liquid emulsions, solutions, wettable powders for spray, aerosols, and dusts. Solutions and dusts are probably the most satisfactory for home use. Preparations that contain nicotine, pyrethrum, rotenone, or organic thiocyanates will kill only those insects that are actually contacted by the insecticide. None of these materials have an appreciable residual action, nor do they leave a poisonous residue after they are applied. For this reason they are among the safest insecticides for home use. However, they are frequently used in combination with more poisonous materials. If the active ingredient is in sufficient amounts, insecticides that contain DDT, DDD, methoxychlor, chlordane, toxaphene, benzene hexachloride, or lindane have varying degrees of residual action. The amount of residual action depends very largely upon the deposit laid down and the kind of insect against which it is directed. Combination insecticides contain more than one toxic material in order to improve their effectiveness and to gain control against a wide range of insects. A commercial dust, for example, may contain benzene hexachloride, chlorinated camphene, and methoxychlor, making it effective against ants, flies, cockroaches, fleas, silverfish, pantry pests, and certain fabric insects. A dust containing pyrethrum and sodium fluoride is effective against ants and cockroaches. Liquid concentrates may also contain more than one insecticide. Insecticides, dusters, and sprayers can be purchased at hardware stores, feed and fuel stores, seed stores, nurseries, local distributing plants of insecticide companies, and other sources. Be sure to read the label on the package before purchasing an insecticide; it is a guarantee of the contents. Equipment such as dusters — and particularly sprayers — should be kept clean. Insec- ticides should be stoied in airtight containers out of the reach of children. FOR RECOMMENDED CONTROL MEASURES AGAINST INDIVIDUAL INSECTS (LISTED ALPHABETICALLY) TURN PAGE [5] Read these precautions before using insecticides Certain precautions must be followed when using insecticides. Although there is little danger of serious residue from preparations using nicotine, pyrethrum, or rotenone, care should be taken to avoid wetting foods with any of these materials when applied as sprays. Solutions containing contact insecticides are inflammable and should not be applied near open flames of any kind. When solutions used for residual sprays contain DDT, DDD, methoxychlor, chlordane, benzene hexachloride, or lindane, the following precautions should be followed: 1 . Do not fill the air with spray mist. Apply the solution directly to the surface to be treated. This can best be accomplished by using a rather coarse spray or by applying with a brush. 2. Do not wet surfaces to the point where the solution will run off. 3. Do not use on any food, around food preparation areas, or on food utensils. 4. Do not empty sprayers containing unused solution where there is danger of waste flowing into fish pools or similar situations. 5. Do not use solutions or oil-based sprays on animals. 6. Be careful when using solutions on highly polished surfaces; some solvents will mar the finish. Highly refined kerosene, one of the most desirable solvents, may remove polish slightly if allowed to drip on such surfaces. 7. Do not breathe vapors or permit solutions to remain on hands or other portions of the body. When applying solutions, protect the body and bare skin as well as possible. Wash hands and face thoroughly with warm water and soap fol- lowing each application. (Materials such as DDT in oil solution are readily absorbed through the skin.) Change clothing if it becomes soaked with spray. 8. Before treating wallpaper and certain fabrics, make certain the solution will not stain or discolor the material. 9. DDT and similar solutions will leave a residue if sprayed on dark surfaces and will fog windows. Sprays containing chlordane leave no visible residue on dark surfaces. 10. Do not apply solutions to plants of any kind. When these insecticides are used as dusts, wettable powders for sprays, or emulsions, all of the precautions listed above except 5 and 6 should also be followed. In these formulations DDT and related compounds are less injurious to man since they are not as easily absorbed through the skin. Little hazard need result from the use of household insecticides that contain DDT and related compounds as recommended in this circular. Aerosols can be used in the home, but only such insects as flies and mosquitoes are easily controlled by this method. Insects in protected locations are not killed. [6] ANTS Argentine ant, Iridomyrmex humilis Mayr Ants are social insects that are found nearly everywhere, living in colonies. De- pending upon the species, they build their nests in open ground, under stones or wood, in wood or decaying trees, or in any other location that affords desired protection. Ants are generally wingless except at mating time, when swarms of winged males and females which have recently emerged can be seen. Soon after mating the males die, and the females or queens lose their wings and attempt to establish new colonies. Feeding habits vary with species. Some eat vegetable matter, seeds, or fungi. Others feed upon the moisture given off by plants or the honeydew excreted by certain insects. Still others feed upon the bodies of insects, small animals which they attack, or dead animals. Ants may injure lawns, gardens, and orchards by their nesting habits. Some feed on crops, fruit, seeds, and nuts, and those that feed on honeydew protect the insects that produce it. Some species of ants will be attracted into homes by the presence of sweets or fatty substances. The most annoying household ant in California is the Argentine ant, Iridomyr- mex humilis Mayr, which has spread over most of the state since it was first noticed in 1905. It is very aggressive and, where strongly established, has driven out and largely replaced many of the native species. Carpenter ants, Camponotus species, are the largest found in California, meas- uring up to a half inch or more in length. They may damage homes by constructing nests in timber, although they do not feed on the wood itself. Other common household varieties in- clude the odorous house ant, California velvety tree ant, pyramid ant, California fire ant, western thief ant, Pharaoh's ant, tiny black ant, and the pavement ant. What to do: On the market are a number of poisoned ant syrups which, if properly used, will result in excellent control of the Argentine and other sweets-loving ants. Directions on the con- tainers should be followed carefully. DDT and chlordane are very effective in controlling ants. DDT solutions should be no less than 5 per cent DDT, and chlordane solutions should be at least 2% per cent chlordane. In the house, these solutions can be ap- plied with either a sprayer or a narrow brush. If a brush is used, apply the solu- tion along the runways or paths followed by the ants. If the ants change their run- ways, repeat the operation until the ants disappear, which should be within a few days. When these insecticides are applied as sprays, direct the spray to wet the run- ways. DO NOT spray near open flames (see page 6 for other precautions) . To control ants out of doors, apply a solution or dust to nests or other loca- tions frequented by the pests. If a DDT dust is used, it should be 10 per cent DDT. A spray made of 9 ounces of 40 per cent wettable chlordane powder in 1 gallon of water will result in excellent control when applied as a coarse spray. Carpenter ants found in timbers can be controlled by injecting dusts contain- ing DDT or chlordane into the burrows. [7] BEDBUGS -\2 v If Bedbug, Cimex lectularius Linn. The common adult bedbug, Cimex lec- tularius Linn., is a wingless, flattened in- sect measuring about 3/16 inch long by 1/8 inch wide. The dusty red color of the unfed bug changes with feeding to bright red, and the body becomes much thick- ened. The slender, pointed mouthparts are adapted for piercing skin and suck- ing blood. Infestations of bedbugs are usually ac- companied by a disagreeable "buggy" odor. Often, however, the first indication will be the discovery of itching bites in the morning. Bed sheets in an infested room will usually have numerous dark brown stains deposited by the bugs as they feed. Small oval eggs are laid by adults in their usual hiding places (see below), where they hatch in about a week in warm weather. Young bugs are similar in appearance to the larger adults and have similar feeding habits. They develop for 7 weeks or longer, casting their skins 5 times before reaching adulthood. What to do: Lightly spray a 5 per cent DDT solution in kerosene over the frame and springs of the bed and over both sides of the mattress. Use a coarse droplet spray directly on the objects treated; DO NOT fill the air with a mist. An application of 3 to 4 fluid ounces of spray to a double bed should be suf- ficient. This solution is inflammable; see page 6 for precautions. For quicker results, other possible hid- ing places, such as cracks in floors and walls, behind baseboards and pictures, and in overstuffed furniture should be sprayed. DDT may also be applied effectively as a 5 per cent dust, using a small hand duster. Apply a thin film of dust to the bed and other hiding places of the bed- bugs. The disadvantage of dust is its un- sightliness. Five per cent emulsions or water sus- pensions of DDT are also effective in controlling bedbugs. The suspension leaves an unsightly residue. There are also other commercial insecticides which can be used effectively. Heating infested rooms to tempera- tures of 120 degrees to 130 degrees F will kill bedbugs, but this method is often impractical. A temperature of 140 de- grees F at 2 feet from floor level may in- jure furniture finishes. Serious infestations may require fumi- gation with hydrocyanic acid gas by a licensed pest control operator. This method, which is rarely needed, requires special precautions for human safety. BOX ELDER AND CORIZID GRASS BUGS Box elder bug, Leptocoris trivittatus (Say) Box elder bugs and corizid grass bugs are among those insects that live outdoors but enter homes under certain circum- stances. Box elder bugs, Leptocoris trivittatus (Say), frequently invade residences dur- ing winter. They are small, dark bugs, about % inch long, with red longitudinal lines on the back. They do no damage. [8] Corizid grass bugs are small bugs, about % inch long and variable in color, that may enter homes when the plants from which they suck juices dry up. Normally they do not attack man, but at night they may drop from lights onto a person and probe his skin in search of moisture. No serious effects will be suf- fered from such attacks. What to do: Apply a contact spray directly on the insects. Where box elder bugs are concentrated in large numbers on the trunks of trees, dust them thoroughly with a 10 per cent DDT dust. To prevent their entry into the house, follow precautions listed under preda- ceous and darkling ground beetles on page 26. BROWN DOG TICKS Brown dog tick, Rhipicephalus sanguineus (Latr.) The brown dog tick, Rhipicephalus sanguineus (Latr.), is a small species about % to almost % inch long which is often found on dogs in California. A domestic species, it concentrates about buildings where dogs are kept rather than in woods or open country. The "head" of the adult is six-sided when viewed from above, while that of wood ticks found on dogs is more or less rectangular. The color of the adult tick is a reddish brown, changing to a bluish shade in fully fed females. A single female may lay from 1,000 to 3,000 eggs in cracks in the roofs of kennels or in ceilings of buildings, where adult ticks migrate after feeding. Growing ticks feed on dogs and hide in cracks between feeding periods. What to do: Both the infested dog and the rooms he frequents must be treated if control is to be effective. Thoroughly dust the dog with a 10 per cent DDT powder, or wash him with a solution made by mixing 2% ounces of 50 per cent wettable DDT powder in 1 gallon of water. Dogs infested with wood ticks as well as brown dog ticks will benefit from the above treatment, but will receive protec- tion from reinfestation only when treated with the DDT wash. Such protection will last two or more weeks if the dog is not washed following treatment. Treat cracks in woodwork, particularly those around ceilings and porches, with a 10 per cent DDT dust, 5 per cent DDT emulsion, or a 5 per cent DDT solution in kerosene. The latter solution is in- flammable; see page 6 for precautions. Be sure the DDT actually penetrates crevices which may harbor the ticks. Thoroughly clean the dog's bed. Dust infested yards and runways with a 10 per cent DDT powder, or spray them with a 5 per cent DDT suspension or emulsion. The powder and suspension are relatively harmless to most plants, but the emulsion may burn some plants. Insecticides other than DDT may be used effectively. A rotenone wash may be made by mixing 2 ounces of 3 to 5 per cent rotenone powder and 1 ounce of neutral soap in 1 gallon of tepid water. Thoroughly wet the animal with the wash at 3-day intervals until the pests are eliminated. The wash preparation will keep at least a week. If a wash is objectionable, the rotenone powder may be dusted lightly next to the skin on all affected parts of the animal. DO NOT get the powder nor the dip in the animal's eyes. Where staining of wood is not objec- tionable, such as outbuildings, kennels, and fences, undiluted creosote oil may be applied effectively, particularly in warmer regions where the tick may over- winter out of doors. [9] CARPET BEETLES Varied carpet beetle, Anthrenus verbasci Linn. Carpet beetles damage fabrics by eat- ing holes in them. Under certain condi- tions, an article may be nearly destroyed. Damage by carpet beetles can be dis- tinguished from that of clothes moths by the absence of the webbing spun by moths. The larvae of carpet beetles cast off their skins several times, and these hair-covered skins help to identify their work. All damage is done by the larvae, which hatch from eggs laid on the ma- terial by adults. Larvae of the varied car- pet beetle, Anthrenus verbasci Linn., and the bird-nest carpet beetle, Anthrenus lepidus Lee, are short, robust, and stubby, and have the hairs arranged in a neat pattern. Larvae of the black carpet beetle, Attagenus piceus Oliv., are elon- gate, reddish brown above, pale beneath, and have a tuft of very long hairs at the tail end. Adult carpet beetles are small, oval, somewhat flattened insects with short legs. The varied and bird-nest carpet beetle adults are about % inch long and are mottled black, brownish, and white. The black carpet beetle adult is about 3/16 inch long and is all black. The adults, which fly readily, are at- tracted to daylight and may collect at windows. During their active period in the spring, they gather in large numbers on flowers where they feed on pollen and nectar. There is usually only one gener- ation a year. The larvae prefer dark, undisturbed locations in which to develop. Since most household furnishings and clothing are less suitable as a food than the raw prod- ucts from which they are made, larvae will most frequently be found in the nests of rodents, birds, and insects and in bedding places of animals. In these places they feed upon unprocessed hair, feathers, wool, fur, insect remains, and other natural dried animal products. These natural breeding places are im- portant sources of infestations for homes. However, the larvae of some species can complete their development on plant ma- terial such as pollen or certain cereal products. The varied carpet beetle and the black carpet beetle are known to be able to develop in certain stored products other than those from animal sources. Although primarily a pest of material made from animal products, carpet beetles will under certain conditions seri- ously attack goods made from nylon. Damage can be avoided by using ma- terials on which they do not feed, such as cotton, for drapes and furniture cover- ings. What to do: Prevention of infes- tations, of course, is the best method of control. Various precautions which can be taken are listed on page 11. If carpet beetles are discovered in the house, however, destroy them immedi- ately with a contact spray. Sprays con- taining pyrethrum as the active killing agent will destroy only those insects con- tacted, but a spray containing 5 per cent DDT in highly refined or deodorized kerosene will provide long-lasting pro- tection. Chlordane, lindane, or toxaphene sprays also afford some residual protec- tion. Contact sprays are best applied with power sprayers, although hand sprayers can be used. Be sure to wet hidden breed- ing places such as loose baseboards, cracks in the floor, and other locations that are likely to harbor the pest. DO NOT use contact sprays near fires or flames of any kind; see page 6 for other [10] precautions. Excellent control in such locations can be obtained by applying DDT contact sprays with a paint brush. Treating walls and floors with a resid- ual spray will not kill those insects in- festing upholstered furniture and other articles subject to attack. Spray these ob- jects lightly with DDT to help control larvae and prevent damage. Where pos- sible, spray goods on both sides. Other possible methods of destroying carpet beetles are: 3 Dry cleaning. This kills any insects that are present in articles, but does not prevent reinfestation. Placing articles in cold storage will stop feeding by insects and will kill them if temperatures of degrees F or lower are maintained for a day or so. 2. Heating. Insects are killed in about 2 hours if exposed to a temperature of 120 degrees F. Higher temperatures re- quire shorter exposures, but DO NOT let the temperature rise above 140 degrees F. This method of killing carpet beetles can be used in areas where high summer tem- peratures occur and heating facilities are available. The insects must be actually subjected to the lethal heat, and the temperature in their hiding places will rise more slowly than the air temperature of the room. To insure thorough penetration of heat, the temperature of a room or entire structure should be raised to 125 to 135 degrees F and held there for about 12 hours. 3. Fumigation. You can safely fumi- gate a trunk, closet, or any tight chamber with flake naphthalene or paradichloro- benzene crystals (PDB) . If the container is not tight, line it with heavy paper. Use the fumigants at the rate of 1 pound to each 20 cubic feet of chamber space; % pound will treat a good-sized trunk. Scatter the fumigant between the lay- ers of articles to be treated, or between layers of thin paper separating the ar- ticles. Both fumigants are most effective at temperatures of 70 degrees For higher. Under favorable conditions, 7 days' ex- posure will kill any insects infesting fabric articles. If the container is reason- ably tight, one application a year should insure perfect protection of the goods. A closet can be used as a storage cham- ber if it is made fairly tight. Apply the fumigant to the floor and shelving at the rate of 1 pound to each 20 to 50 cubic feet of space. Keep replenishing the sup- ply before it completely evaporates. Leave articles in the closet as long as possible, but air them before wearing. Any article kept in the closet will be fully protected. If piano felts become infested, place 1 to iy 2 pounds of paradichlorobenzene in a porous bag inside the piano. Close all openings and cover the piano with a tar- paulin for about a week. If possible, the family should be away from the house during this period. After fumigation the piano should be opened and aired. A very satisfactory and safe liquid fumigant is a mixture of 3 parts by vol- ume of ethylene dichloride and 1 part by volume of carbon tetrachloride. This mix- ture is available in limited amounts on the market under its chemical name or trade names. It is a colorless noninflam- mable liquid with an odor somewhat similar to chloroform. It kills faster than naphthalene or para- dichlorobenzene; at 70 degrees F or higher, fabric insects are killed in 24 hours. Keep the fumigation chamber tight and place the fumigant in a shallow pan on top of the materials to be treated at the rate of % ounce to 1 cubic foot of chamber space. DO NOT attempt to fumigate an entire dwelling. This should be done only by a licensed pest control operator. The fumi- gants generally used for this purpose are very dangerous unless handled by experi- enced operators. To prevent future infestations: 1. Destroy nests of birds, rodents, and insects (particularly bees and wasps) situated in or close to the house. The more protected from the elements these [11] nests are, the more likely they are to be infested with larvae. (Bird nests need not be destroyed until after the young birds have been reared; they are not sources of infestation until after this period), keep the bedding places of pets clean. 2. Clear away the lint that accumulates in attics, furnace vents, cracks in the floor, and behind baseboards. Fill cracks in floors and loose-fitting baseboards with plastic material or similar fillers. 3. Destroy untreated skins, neglected insect collections, discarded woolen rags and clothing, and other materials of little value that foster breeding of carpet beetles. 4. Clean carpets frequently with a vacuum cleaner. Clean the underside when possible. Carpets tacked down or extending to the edge of rooms afford favorable breeding places for larvae. 5. Occasionally move furniture, rugs, drapes, and other articles subject to at- tack. This not only disturbs locations suitable for carpet beetle development, but also aids in cleaning. The less dis- turbed an area the more favorable it is to the pest. Frequently clean upholstered furniture, drapes, and similar articles. 6. Thoroughly brush clothing and other susceptible articles and hang them in the sun on warm bright days. 7. Have clothes dry-cleaned regularly. This kills any pests in the articles, but will not protect against reinfestation. Clothing that is not injured by dry clean- ing can be protected from attacks for as long as 2 years (or until it is dry-cleaned) by wetting with a 5 per cent DDT spray. Treated materials should be hung out- doors until they are dry. Excellent protection is obtained where the DDT content of the treated goods equals % to % P er cent oi the dry weight of the garments. Deposits greater than % per cent are liable to be visible on dark clothing. Toxaphene also gives good pro- tection, but— like DDT— is removed by dry cleaning. Articles that can be thoroughly wetted may be impregnated with a saturated solution of sodium fluosilicate. To pre- pare this solution, place 1 ounce of sodium fluosilicate in 1 gallon of water, shake the mixture several times, and pour off the clear liquid. To this add 1 or 2 tablespoons of a wetting agent. Apply the solution as a spray, thoroughly wet- ting the article. Keep any unused solution out of the reach of children. 8. Whenever possible in furnishing your home, use materials such as cotton upon which carpet beetles do not feed. CENTIPEDES Centipede, Cermatia forceps (Raf.) Centipedes are flattened, many-legged, wormlike creatures that move rapidly and are normally found outdoors. Oc- casionally they enter houses where they may crawl into clothing, beds, shoes, and other dark places. They feed upon insects and small animals. The bite of certain California species may be quite painful and can cause ap- preciable swelling of the affected part. However, the effects normally are not serious. One of the most spectacular species encountered in homes is the house centi- pede, Cermatia forceps (Raf.) . It usually moves with such speed that only a fleet- ing glance is possible. It is brownish in color with black stripes on the long legs 12 and 3 longitudinal black stripes on the upper surface of the body. The house centipede usually lives in damp cellars, but may rove throughout the house in search of its prey (including insects such as flies, cockroaches, and moths). It can inflict a painful bite on man, but the effects are not severe. What to do: Spray clear creosote on joists and subfloor supports of buildings and on the ground under the buildings. This kills any pests contacted and seems to repel future invaders for an indefinite period. Rough outbuildings such as privies and garages also should be treated with clear creosote. Eliminate accumulations of debris, stacks of lumber, or stored household effects from basements or locations near the house. These serve as hiding places for the pest. CEREAL MITES Cereal mite, Tyrophagus lintneri (Osb.) The cereal mite, Tyrophagus lintneri (Osb.), is a widely distributed pest and is frequently found in enormous numbers in cereal and cereal products. It is a pale- colored, wingless, smooth, soft-bodied, microscopic organism with 4 pairs of legs. There are long hairs on the back and legs. In large numbers the mites appear as loose, fluffy masses of gray powder. This is due to the mingling of castoff skins with the living insects. In the house they sometimes swarm from infested materials and may even attack humans handling infested materials, causing a severe skin condition known as "grocer's itch." Moist conditions favor their develop- ment, and their appearance in large num- bers is usually a sign that the product they are infesting has a higher than nor- mal moisture content. What to do: Locate and destroy the infested material. Clean the surroundings and keep them as dry as possible. Heat- ing an infested unit at 130 degrees F for several hours will kill any mites present. To prevent future infestations, keep the storage area dry and follow precautions listed under pantry beetles on page 25. CLOTHES MOTHS Casemaking clothes moth, Tinea pellionella Linn. Clothes moths injure fabrics by eating holes in them; a small amount of feeding may result in serious damage. The pest is most destructive when articles subject to attack are left undisturbed for long periods. Damage caused by clothes moths can be distinguished from that of carpet beetles by the silk-lined tubes made by the webbing clothes moth, Tineola bisel- liella Hum., and the silken parchment- like cases constructed by the casemaking clothes moth, Tinea pellionella Linn. Carpet beetles spin no webbing. The webbing clothes moth and the casemaking clothes moth are the most important of the destructive species. They pass through 4 stages of development: moth, egg, larva, and pupa. All damage is done by the larvae or caterpillars. Both moths are small, the adults with wings folded measuring about *4 inch in length. The adult webbing clothes moth is buff-colored and has a satiny sheen; [13] hairs on the head stand upright and are reddish in color. The casemaking clothes moth is similar, except that it has in- distinct dark spots on the wings, and the hairs on the head are lighter in color. These species are not strong fliers and are not attracted directly to lights. They prefer darkness, but will flit about the margins of lighted areas. When infested fabrics are disturbed, the moths run rapidly or fly to conceal themselves in folds or other secluded places. This ability to disappear is characteristic. Adult moths live for a period upward to a month, during which a female may lay as many as 300 eggs. Depending upon temperatures, the eggs hatch in about 1 to 4 weeks. Larvae have pearly white bodies and dark heads and are about % inch long when fully grown. On some foods their bodies may be nearly translucent, while on others they become more opaque and somewhat dingy in color. Larvae of the casemaking clothes moth construct a silken, parchment-like case which they drag along wherever they go. When disturbed they retreat into the case. Larvae of the webbing clothes moth live within silken burrows which they con- struct and are capable of moving rapidly through them. The time required to complete a life cycle will vary from 3 months to more than a year, depending upon tempera- tures and quality of food. The natural food of clothes moths consists of un- processed materials such as pollen, hair, feathers, wool, fur, insect remains, and other dried animal products. Any accumulations of these materials in cracks in the floor or other protected places are very likely to be infested and furnish breeding places. What to do: Follow the control meas- ures outlined for carpet beetles on page 10. Sunning and brushing are more effec- tive against clothes moths than against carpet beetles since brushing crushes and dislodges eggs. In brushing, pay par- ticular attention to seams, folds, and similar places. The pest does not like sunlight; larvae will drop from goods hung in bright sun. CLOVER MITES Clover mite, Bryobia praetiosa Koch The common clover mite, Bryobia praetiosa Koch, is one of the larger mites, measuring 3/100 inch in length. It varies in color from rusty brown to dull green. Hordes of these barely visible pests may invade California homes at almost any season of the year, apparently seek- ing protection from the elements. At times they seem to migrate without ob- vious cause, although invasions are often correlated with a drying up of lawns or plants adjacent to the house. The mite feeds on the leaves of such plants as clover, alfalfa, peas, grasses, and numerous herbs, shrubs, and trees. Infestations can usually be traced to in- fested plants very close to or touching the house. The clover mite does not attack man or other animals, but considerable irritation has been reported on at least one occasion by bedridden patients in a hospital where the mites were observed in large numbers crawling on the walls and beds. What to do: Spray odorless white kerosene directly on the accumulations of mites, taking care to treat cracks where they may hide. Many commercial house- hold sprays, such as DDT solutions in [14] kerosene, will kill the mites upon contact. All kerosene sprays are inflammable; see page 6 for precautions. To prevent future entry of mites, dust window sills and door sills with a sulfur dust. If possible, remove vegetation in- fested with these mites from contact with the house. COCKROACHES German cockroach, Blatella germanica (Linn. Cockroaches are flattened, fast-run- ning, nocturnal insects that are fond of warm, moist situations. They contami- nate food and often leave a very un- pleasant odor on the materials they in- fest. They are general feeders and, in ad- dition to most foods, will feed upon such materials as bookbindings and fabrics. The American cockroach, Periplaneta americana (Linn.), is the largest of the 5 species most commonly encountered. Adults are 1% to 2 inches long and have reddish-brown wings completely cover- ing the abdomen. The Australian cockroach, P. austra- lasiae (Fab.) , is very similar, but is only 1 to 1% inches long. It is easily distin- guished by a yellow streak on the outer edge of the basal half of the outer pair of wings. Probably the most common and annoy- ing species in California is the German cockroach, Blatella germanica (Linn.), which is % inch l° n g, light brown in color, and has two darker longitudinal stripes on the shield covering its head. The most recent species to enter the state is the brown-banded cockroach, Supella supellectilium (Serv.), which is % to % i ncn long. It is pale brown with two paler crossbands on the wings. The Oriental cockroach, Blatta orien- talis (Linn.) , is l 1 /^ inches long and black to brownish black in color. The male has short wings that do not entirely cover the abdomen. Adult females are nearly wing- less and are unable to fly. Cockroaches lay their eggs in leathery capsules which are frequently seen pro- truding from the abdomen of females. These capsules are eventually dropped or attached to some object. Newly hatched roaches are very small, but resemble adults sufficiently to be recognizable. In growing they cast their skins several times. What to do: Find the secluded spots behind kitchen cabinets, in back of loose baseboards, and in dark corners where the pest hides during the day. These may be located at night by suddenly turning on the lights in a room and watching where the roaches run. Dust these hiding places with a 10 per cent DDT powder. Spray the undersides of chairs, tables, drawers, sinks, and similar locations with a 5 per cent DDT solution. Be careful not to contaminate food and utensils with the spray, and DO NOT use DDT solutions near flames of any kind (see other precautions on page 6). If the cockroaches are not completely eliminated, repeat the treatment within 2 or 3 weeks. Household preparations containing chlordane are extremely effective against cockroaches and should be used in the same manner as DDT, but at % the con- centration. Many cockroach powders contain so- dium fluoride, but its poisonous nature requires a great deal of caution in apply- ing. Its effectiveness is increased when used in combination with pyrethrum. The most effective preparation contains 75 per cent sodium fluoride and 25 per cent pyrethrum. [15] Sodium fluosilicate is sometimes used instead of sodium fluoride since it is less poisonous. However, follow carefully directions given on the container when using any of these materials. To prevent future infestations, ex- amine carefully all supplies, containers, and other materials brought into the house. Kill every cockroach encountered. Follow precautions listed under pantry beetles on page 25. CRICKETS Field cricket, Gryllus a The common field cricket, Gryllus as- similis (Fabr.), is a large, brown to black, swift-moving insect with long feelers. Nocturnal in habits, these pests breed outdoors but tend to migrate into houses when in large numbers. Indoors they feed on fabrics, particularly if they are soiled or food-stained. They are likely to be most troublesome in warmer climates and in regions where there is considerable uncultivated land. At night they are attracted to lights and may collect about them in large numbers. What to do: Apply dusts containing 5 per cent DDT or 2 per cent chlordane to floors along the baseboards. If there is no danger of contaminating foodstuffs, blow the dust into cracks and other hiding places. By applying it across door sills and along foundations, you can kill the pests before they enter the house. Pyrethrum-sodium fluoride or pyreth- rum-sodium fluosilicate are also effective, but must be used with great caution as they are severe stomach poisons. Follow carefully directions on the containers. Where crickets are extremely abund- ant, poison baits may be used. This should not be necessary about the house. FLEAS Flea, Ctenocephalides felis (Bousche) Adult fleas are small, dark reddish- brown insects with legs well developed for jumping. Their bodies are laterally compressed and compact, with definite divisions marked by stiff, backward- pointing spines. These characteristicsper- mit the insects to move rapidly through the hairs of the host. The mouthparts are developed for piercing skin and sucking blood. The bite of a flea not only leaves an itching, hard, red spot about the puncture, but some species act as vectors of plague, endemic typhus, tularemia, or other dis- eases and parasites of man. Fleas commonly found on dogs and cats will frequently transfer their feeding to man, particularly when infested pets have the run of the house. The same is true of certain fleas normally found on rats and other rodents. Man is most often attacked by a species known as the human flea, Pulex irritans Linn. It is an elusive pest which can cause extreme annoyance, a single flea biting several times over a short period. Flea eggs are small, rounded, and white, and are usually found on the floor, [16] ground, bedding, or similar locations. They hatch in 2 to 4 days, producing tiny, hairy, wormlike larvae which feed on dried organic debris. After 8 or more days of growth, the larva spins a silken cocoon within which it transforms into the pupa, a quiet stage of transformation. From 5 to 10 days later, the adult flea emerges. Many people seem to develop a certain tolerance to flea bites when continually exposed to them. However, present con- trol methods are so effective that there is little excuse for flea-infested homes or public gathering places. What to do: On humans, dogs, and most other animals— except cats, apply a 10 per cent DDT in pyrophyllite dust. One to 2 teaspoons of dust is sufficient for an individual. Apply this same dust in the house, basement, and rat burrows, and on lawns and bare ground under buildings. A 5 per cent DDT solution in kerosene, or a 5 per cent DDT emulsion, may be sprayed in the house at the rate of approximately 1 gallon per 4,000 square feet of surface. Kerosene solutions are inflammable; see page 6 for precautions. Since DDT kills slowly, some live fleas may be seen for several days following the treatment. Rapid removal of fleas on dogs and cats may be obtained with flea pow- ders containing pyrethrum or rotenone. However, since some fleas will revive fol- lowing this type of treatment, collect them by combing the animal over a paper. Lawns infested by fleas may be sprayed with a 40 per cent nicotine sulfate solu- tion mixed 1 part in 400 parts of water. This treatment is most successful when the lawn is closely clipped; it may be necessary to repeat the applications 2 to 3 times. Before applying insecticides, thor- oughly clean the house: remove rubbish, vacuum rugs, and burn or cleanse bed- ding used by pets. Fleas can also be controlled by scatter- ing flaked naphthalene over the floors of infested rooms— about 5 pounds per room— and sealing the rooms for 1 to 2 days. Remaining naphthalene flakes should then be swept up and stored in a tight container for future use. FLIES Housefly, Musca domestica Linn. The common housefly, Musca domes- tica Linn., is far more than a nuisance. With its ability to reproduce rapidly and to move quickly from filthy surroundings to the food of man, it can be a dangerous carrier of such diseases as typhoid fever and bacillary and amoebic dysentery. A single fly may lay more than 2,000 eggs in 30 days. These are laid in horse manure or other excrement, in garbage, kitchen refuse, lawn clippings, and other decomposing plant and animal matter. In warm weather the egg may hatch in less than 2 days, producing a white maggot or larva. After 5 or more days of growth and development, the maggot changes into a quiet stage of transformation— the oval, brown pupa. After 4 or more days in this stage, the adult fly emerges. In warm or protected environments, fly re- production may continue throughout the year. In cities housefly infestations usually can be traced to their breeding source within the distance of a city block. How- ever, these pests may fly or be trans- ported by wind or vehicles for a mile or more. In addition to the grayish-black house- fly, the householder may encounter sev- [17] eral other kinds of flies which are con- trolled in the home in the same manner as the housefly, although control of their maggots varies as indicated below. The stable fly, Stomoxys calcitrans (Linn.), often called the "biting house- fly," since it resembles the true housefly, has a slender pointed beak with which it can pierce the skin and draw blood. It is normally an outdoor fly which feeds on domesticated animals, but in rainy weather or in the autumn, particularly, it tends to enter houses. To control its maggots dispose of stable manure or urine-soaked straw daily, as well as moist decaying vegeta- tion such as lawn clippings or plant masses cast upon shores of lakes or beaches. The lesser housefly, Fannia canicularis (Linn.), and the latrine fly, Fannia sca- laris (Fabr.), are frequently seen flying back and forth in the middle of a room. They seldom light on human food and are therefore less dangerous than the true housefly. The maggots of these species develop from eggs laid in well-decayed, semiliquid vegetable matter or in excre- ment. The adults resemble the true house- fly. The false stable fly, Muscma stabulans Fallen, is larger and stouter than the true housefly and has a general dark gray ap- pearance. It cannot bite, but may enter houses and lay its eggs on foods, particu- larly those that are slightly spoiled or odorous. Blowflies are somewhat larger than the common housefly, and several of them are characterized by brilliant metallic colors, such as the black blowfly, Phormia; the bluebottle, Calliphora; and the green- bottles, Lucilia and Phoenicia. In flying about the house, these flies make a much louder droning buzz than do true house- flies. They will lay eggs on exposed meat, resulting in what is known as "flyblown flesh," and occasionally in old or dirty wounds. In the latter cases, the resulting maggots will attack living tissue. Fleshflies (sarcophagids) look like overgrown houseflies; the more common ones have a checkerboard pattern on the abdomen. They differ in their habits in that they deposit living maggots— instead of eggs— in decaying flesh and excrement, especially dog stools. What to do: For immediate knock- down of flies, use a space or contact spray directly into the air of the room. These sprays, of which there are many effective brands on the market, are of little resid- ual value if sprayed on walls or windows. They usually contain pyrethrum and an activator for quick knockdown and DDT, rotenone, or organic thiocyanates to in- crease killing power. Aerosol bombs are convenient to use in the home, but are usually more expen- sive than the space sprays mentioned above. For more lasting control use residual type sprays. It is rarely necessary to ap- ply these sprays inside the house, but in such cases use only DDT or methoxy- chlor emulsions or solutions. These may be applied with a paint brush or spray gun to such places as window sills or walls inside the house and to garbage cans, screens, doors, and other favored resting places for flies outside. Apply residual insecticides with a coarse droplet spray at a rate of 1 gallon to about 1,000 square feet of surface for emulsions or solutions. When suspen- sions are used, 1 gallon will cover about 500 square feet. Solutions containing contact insecticides are inflammable; see page 6 for precautions. The following formulations are among the best available: suspensions of 2% per cent DDT or methoxychlor or % P er cent lindane; emulsions of 5 per cent DDT or methoxychlor, 2 per cent chlor- dane, or % per cent lindane; solutions of 5 per cent DDT or methoxychlor, or 2 per cent chlordane. Instructions for ob- taining these concentrations should ap- pear on the labels of the commercial in- secticides. [18] Since houseflies in many areas have become resistant to DDT and other chem- icals, their residual control with insecti- cides alone is often unsatisfactory. To prevent flies entering the house, keep all doors and window screens shut. A single door left open serves to make a house a flytrap. The use of DDT and other chemicals is not a substitute for sanitation methods. In neighborhoods where flies are trace- able to animal manure, community action may be necessary to enforce proper dis- posal or treatment. Since the life cycle of the fly may be completed in a week to 10 days, all breed- ing sites should be treated or disposed of twice a week. This applies to garbage, lawn clippings, and other organic debris. Burning of such material is an effective means of fly control, but often it is not practical. In such cases, as in areas where there is no regular garbage collection, dump the waste into a pit, spray it with a 5 per cent DDT solution, and cover with a layer of earth. Manure should be composted in com- pact heaps, and the outside of the piles sprayed with a 5 per cent DDT or meth- oxychlor suspension whenever fresh ma- nure is added. Fresh manure spread daily in thin layers in fields as a fertilizer will seldom be a source of fly breeding. Frequently homeowners will find they are bothered with swarms of flies shortly after spreading manure on lawns as a fertilizer. This is due to the fact that the manure was infested with maggots or pupae at the time it was delivered. FLOUR AND MEAL MOTHS Indian meal moth larva iff Indian meal moth, Plodia interpunctella (Hbn.) Flour and meal moths are pantry pests that complete the immature stages of de- velopment in the food they infest. The larvae are pale in color and % mcn l° n g when fully grown. Adults with wings folded are about % inch long. The two most common species found in the home are the Indian meal moth, Plodia interpunctella (Hbn.), and the Mediterranean flour moth, Ephestia kuhniella Zell. All damage is done by the larvae, which attack a wide range of prod- ucts, including cereal and cereal products, chicken mash and similar foods, dried fruits, dehydrated vegetables, shelled nuts, chocolate, candies, and various other confections. The larvae spin webbing over and through materials they infest, a char- acteristic which distinguishes their dam- age from that of pantry beetles. Upon completing their development the larvae usually leave the foodstuffs and spin silken cocoons near by. Fragments of grass and food are generally worked into these cocoons, where the larvae pupate and transform into adults. When infestations are heavy, mature larvae frequently wander away from the infested product and are often found far from the original food source, even in other parts of the house. The larvae of both species are very similar and are sparsely covered with rather long hairs. The Mediterranean flour moth larva has black spots at the base of the hairs, particularly those along the back and sides, which are absent in the Indian meal moth. [19 The adult Mediterranean flour moth is slightly larger than the Indian meal moth, and its forewings are lead gray, speckled with black or with transverse wavy black lines. The hind wings are of a uniform lighter gray color. The outer two thirds of the forewings of the adult Indian meal moth are cop- pery brown, while the basal third is pale gray. The hind wings lack distinctive markings and are more or less uniformly gray. What to do: Follow control measures suggested for pantry beetles on page 24. LICE [: \ ''■•■> Human body louse, Pediculus humanus corporis DeGeer Man may be infested by 3 different species of lice: the head louse, the body louse or cootie, and the crab louse. Their transmission and multiplication are fos- tered by crowing and unsanitary living conditions. They all cause much irritation to the individual, and the body louse is an important means of transmitting such human diseases as epidemic typhus, re- lapsing fever, and trench fever. The head louse, Pediculus humanus capitis DeGeer, spends its entire life on the hairy part of the human head. It is a flattened insect, whitish to blue-gray in color (depending on how recently it has fed), and up to % inch long. It derives all its food by sucking blood. The female fastens from 3 to 9 eggs a day to the hair. The eggs hatch in 5 to 10 days, and the young lice— looking like smaller edi- tions of the adults— feed and mature in about 10 days. Adults live for a month or longer. The body louse, Pediculus humanus corporis DeGeer, looks like the head louse, but lives mainly on clothing near the body. The eggs are fastened to cloth- ing, usually under seams. They require about 8 days to hatch, and 8 more days elapse before the young louse becomes an adult. The young lice need food within a day after hatching. The crab louse, Phthirius pubis (Linn.), also known as the pubic louse, is a short, broad insect about % mcn long with thickened, crab-like legs. It lives in the pubic region and armpits, but may be found on any hairy portion of the body— even the eyebrows. Eggs are fastened to body hairs and require 8 days to hatch; the young mature in about 16 days. The lice are spread by physical contact, exchange of clothing and towels, and stray individuals on bedding and furniture. What to do: Use a 10 per cent DDT powder to control all species of human lice. For head lice, dust a teaspoonful of the powder thoroughly into the hair. One treatment should be sufficient if the hair is not washed for 10 days. Otherwise a second treatment will be necessary to kill lice hatching from eggs. A 15 per cent solution of lethane #384 special (n-butyl-carbitol-thiocyanate) in highly refined kerosene applied as a hair wash is an effective treatment. A 3 per cent rotenone powder may be applied as a dust or a wash. Rotenone is mildly irritating to some people and should be washed off the morning follow- ing treatment. Do not get it into the eyes, for it will cause swelling and irritation. Prepare the wash by mixing 2% table- spoonfuls of rotenone powder and 1 tablespoonful of neutral soap in 1 pint of warm water. This treatment will not kill louse eggs; therefore, 2 applications [20] should be given with an 8-10 day in- terval. Lauryl thiocyanate, pyrethrum, and larkspur solution are fairly effective agents against lice and are frequently used in commercial mixtures. Vinegar will loosen eggs attached to hairs, which can then be removed with a fine-toothed comb. Body lice require treatment of the in- fested person and his clothing. Dust a 10 per cent DDT powder in the hair and thoroughly into the clothing, paying par- ticular attention to seams. Bathing should precede the treatment, but should be avoided for 24 hours afterward. Lice on the body can also be killed by bathing with a kerosene soap emulsion prepared with 2 parts of kerosene to 1 part of soap chips and 4 parts water. A lather should be worked up on the body and left for 15 minutes. A 3 per cent rotenone powder dusted lightly over the body at intervals for 3 weeks will also prove effective, although the precautions listed above under head lice should be observed. Other effective materials include mixtures of naphtha- lene, creosote, sulfur, and iodoform. Clothing and bedding recently used by an infested individual should be dusted with 10 per cent DDT or treated by one of the following methods : 1. Wash with a 5 per cent cresol solu- tion in water or soak for 30 minutes in 2 per cent cresol at 100 degrees F. 2. Bake materials such as leather, felt, and rubber at 140 degrees F for 20 min- utes. DO NOT treat woolens in this manner. 3. Soak cotton and similar materials in water at 150 degrees F for 5 minutes. Storage of clothing for 3 weeks nor- mally eliminates any lice present. Fumi- gation of clothing is not recommended for use in ordinary households. Pubic lice should be treated with DDT powder as described above under head lice, with special attention being given the pubic region and armpits. A rotenone ointment containing 1 part by volume of 5 per cent rotenone to 10 parts petrola- tum is also effective. Mercurial ointment is not recommended due to its poisonous nature. MILLIPEDES Millipede Millipedes are slow-moving, shiny, wormlike creatures with many pairs of legs. They are usually found in damp places that are rich in decaying organic matter. They attack principally the roots and stems of plants, but are seldom very destructive unless present in large num- bers. Under certain conditions millipedes enter homes or crawl up the sides of houses. What to do: Apply a residual contact insecticide containing DDT about the foundations of the house and on the areas frequented by the insect. Seal all cracks and openings through which the pest may enter the house. Remove rubbish and other accumulations about the founda- tions. Keep vines and shrubs from grow- ing over windows or other openings. MOSQUITOES Mosquito, Culex stigmatosoma Dyar Mosquitoes are not only annoying, but may carry encephalomyelitis, malaria, dengue fever, and numerous other serious diseases. They require water in which to develop [21] and lay their eggs. These are laid singly or in rafts on the surface of the water or in depressions which may later contain water. When wet an egg hatches in 1 or more days. The emerging larva (wrig- gler) lives and develops only in water, transforming into a pupa (tumbler) in about 5 days, or longer if the weather is cool. After 2 or more days as a pupa the adult mosquito emerges. What to do: If you live in one of the many mosquito abatement districts in California, report any undue numbers of mosquitoes to the district office, which has trained personnel and equipment for locating and treating the source of breeding. For immediate control in the house, close the infested rooms and apply a kero- sene solution containing pyrethrum, ro- tenone, or DDT (1 per cent or less) as a mist spray into the air. Aerosol bombs contain a propellant liquid gas which emits the insecticide in the form of a mist that remains suspended in the air for some time. Such space sprays or aerosols kill only mosquitoes then in the room. For a residual spray use a 5 per cent solution of DDT in refined white kero- sene. Apply this directly to all the inner walls of the house and to the underside of tables and other furniture. It should be applied as a coarse spray in sufficient amount to wet the surface without caus- ing a runoff of excess liquid. Several other new insecticides appear to be satisfactory as residual spray ma- terials for mosquitoes, but DDT and methoxychlor are the only materials recommended for use in the home. Of these DDT is preferable. Such sprays are inflammable; see page 6 for precautions. When working in a yard where mos- quitoes abound, a few drops of mosquito repellent rubbed over exposed skin sur- faces will usually provide protection from bites for 2 or more hours. Dimethyl phthalate, 612, and Indalone are quite effective, either alone or as mixtures. Oil of citronella is relatively ineffective. To prevent mosquito breeding: Empty all water containers such as tin cans and buckets. Keep water from col- lecting under buildings, particularly checking leaking water pipes and drains. Treat barrels or other open containers of water used for fire protection with 5 per cent DDT, preferably in emulsion form, or add crude cresylic acid diluted 1 to 9 with water until the water has a milky color. Such water containers can also be treated with phenothiazine. Mix 2 pounds of phenothiazine with 1 pound of a wet- ting agent. One teaspoonful of this mix- ture will treat 50 gallons of water. Garden pools, unless stocked with fish, may require weekly treatment with a lar- vicide to prevent mosquito breeding. DO NOT apply DDT to water containing fish; even small amounts are harmful. Cesspools and septic tanks may also serve as breeding areas. All openings to these tanks, such as vents and soil pipes, should be tightly screened. The top should be tightly constructed and ade- quately covered with soil. Pending other corrective measures, the tanks or ponds can be treated weekly by spraying lightly with a solution of 5 per cent DDT in light oil. Tree holes are often overlooked as pos- sible mosquito breeding places. Mosqui- toes will breed by the thousands in a hole that may hold from a cupful to a gallon or more of water during the rainy season. Such holes should be permanently filled and given a cement cap. Breeding may be controlled tempo- rarily by a light spraying weekly with 5 per cent DDT in kerosene or by applying a heavy residual spray of 5 per cent DDT emulsion, which should be effective for 2 months or more— unless heavy rains occur. Cresylic acid painted in such holes will usually control breeding for an entire season. In areas plagued with mosquitoes, doors and windows should be screened with 16-mesh screen. [22] PANTRY BEETLES Bean weevil, Acanthoscelides obtectus (Say) Small beetles found in and near stored foodstuffs may be one of several species which complete their immature stages in the food they infest. For convenience they can be grouped as pantry beetles; their control will differ only according to their feeding habits— whether they are general feeders or restricted feeders. Restricted feeders are very limited in their selection of food, which consists primarily of seeds. They can be detected easily by the presence of small holes in infested seeds, which are cut out by adult beetles as they emerge after pupation. Eggs are laid on the seeds, and upon hatching the larvae bore inside to com- plete their development. If left unchecked, breeding will continue until the infested product is completely destroyed. Restricted feeders include the bean weevil, Acanthoscelides obtectus (Say), the granary weevil, Sitophilus granarius (Linn.), and the rice weevil, Sitophilus oryzae (Linn.). The adult bean weevil is about % inch long, flattened, and somewhat triangular in shape, with a short head. It is velvety gray or brown with pale longitudinal or linear marking. It attacks only beans, peas, and certain other legume seeds. The larvae are legless, grublike, and pale in color. The granary weevil and the rice weevil are very similar in appearance and hab- its. They are primarily a pest of whole grains, but will attack caked cereals such as spaghetti and macaroni. Adults are about Ys inch long, brown to chestnut brown, cylindrical, hard-shelled with a long slender snout. The larvae are legless and pale in color with dark heads. General feeders attack a wide variety of foods, including cereal products (both dried and processed), dried fruit, spices, drugs, confections, dehydrated vege- tables, dried dog foods, fish foods, dried and cured animal products, and other stored materials. The 3 most important species found in the house are the confused flour beetle, Tribolium confusum Duv., the saw- toothed grain beetle, Oryzaephilus suri- namensis (Linn.), and the drugstore beetle, Stegobium paniceum (Linn.). Confused flour beetle adults are about % inch long, smooth, and reddish brown. They are active and wander over a wide area. Their eggs, laid directly in the prod- uct they infest, are sticky, and food par- ticles adhere to them. Larvae are some- what cylindrical, yellowish brown, with a dark head and a pair of slender, pointed growths at the tail end. The pest is most commonly found in cereal and cereal products, although it may infest most other stored food materials. Adult saw-toothed grain beetles are about % inch long, slender, flattened, slightly roughened with a dull, hard, dark brown shell and a row of sawlike tooth projections along either side of the pronotum (plate on body section behind head). Its varied diet includes cereals and cereal products, nuts, dried fruits, and certain animal feeds. The adult drugstore beetle is brown, cylindrical, about % inch long, and has fairly long feelers. Larvae are grublike and when mature construct a small chamber in which they pupate. It attacks a wide assortment of materials, including the coarser cereal products, pet foods, drugs, and spices. Adults fly readily and are often found far from the foods they infest. The pest may enter a home in old furniture, rugs, bedding, or almost any product of plant or animal origin. [23] What to do: If the infestation is dis- covered before the pest starts to migrate, or if the beetle is one of the restricted feeders described above, elimination of the infested product is all that is neces- sary. Otherwise, thoroughly examine all exposed foodstuffs and destroy them if there is the slightest indication of an in- festation. (If the material is of value, it may be fumigated or subjected to heat, as described below.) Clean thoroughly the shelves and floor in the vicinity, removing all accumula- tions of foodstuffs from behind bins or other containers. Place all susceptible products in containers with tight-fitting lids. For several weeks purchase cereals, dried fruits, and similar products in small quantities that can be quickly consumed. Other methods of control include: 1. Cooling and heating. Both low and high temperatures can be utilized in con- trolling food pests. Insect activity ceases at temperatures of 40 to 50 degrees F, and food materials free of infestation will remain so. Prolonged exposure at 40 de- grees F will kill most food insects. All stages of insect life in stored prod- ucts can be killed by exposure to tempera- tures of 120 to 130 degrees F for 2 hours. However, the insect itself must be sub- jected to the heat for the required time. Be sure the proper temperature is reached and maintained at the center of the ma- terial being treated. To insure rapid pen- etration of the heat, spread the material in as thin a layer as possible and stir it from time to time. Small quantities can be sterilized in an oven, but be careful not to scorch the product. In many cases the desired tem- perature can be obtained by merely turn- ing up the pilot light in a gas oven. A longer exposure may be necessary to gain the necessary penetration of heat. If the oven burners are used and kept as low as possible, the usual resulting temperature of 180 degrees F will cause a rapid kill. The oven door may be opened slightly to keep the temperature from ris- ing too high. A thermometer should be used to watch the temperature increase. Insects infesting dried fruits can be killed by dropping the fruit in boiling water for about a minute. Then spread the fruit to dry before storing. 2. Contact sprays need not be used against these pests unless there has been a serious infestation. DO NOT use DDT sprays or those containing chlordane or toxaphene; these sprays have a residual action and should never be used on food, around food preparation areas, or on food utensils. Pyrethrum sprays can be used to treat bins or containers in which bulk foods are placed. They have no residual quali- ties and will kill only those insects ac- tually contacted. Before spraying, clean the storage area thoroughly. After spray- ing, allow the units to dry and air out before restoring foodstuffs. Contact sprays are best applied with a power sprayer, although excellent results can be obtained with hand sprayers. DO NOT spray near fires or flames of any kind; see other precautions on page 6. 3. Fumigation for the control of pantry insects is seldom necessary, unless rela- tively large amounts of food are stored and become infested. The most satisfactory fumigant for household use is a mixture of 3 parts by volume of ethylene dichloride and 1 part carbon tetrachloride. It is available to a limited extent on the market under sev- eral trade names as well as under its chemical name. It is a colorless, nonin- flammable liquid with an odor similar to chloroform. Place the products to be fumigated in as airtight a container as possible, such as a clean garbage can. Pour the fumi- gant into a shallow pan on top of the products to be treated. Place the lid on the can immediately and seal it with scotch or similar tape. The amount of fumigant to use depends on the size of the can or fumigation chamber— at a rate of % ounce to the [24] cubic foot of chamber space. This will be about *4 cup for a medium-sized gar- bage can. Fumigation should be conducted at a temperature of 70 degrees F or higher. After an exposure of 24 to 36 hours, the product should be removed, aired, and placed in tight containers. The airing should be particularly thorough where the treated foods are of high protein con- tent or of medium to high fat content, such as nuts, beans, rice polishings, wheat germ, and soybeans. Store unused fumigant in a cool, dry place— out of the reach of children. To prevent future infestations: 1. Do not leave small quantities of food on shelves. Either place them in con- tainers with tight-fitting lids, or destroy them. 2. Clean shelves and bins and all other locations where there is any possibility for the accumulation of flour or other food materials. Keep them clean. Small amounts of food are all that is necessary for certain pests to live and breed. 3. Do not mix old and new lots of ma- terials. If the old material is infested, the pest may quickly infest the new. 4. Clean old containers before filling them with fresh materials. They may be contaminated and cause a new infesta- tion. 5. Do not purchase broken or damaged packages of food materials. They are more likely to be infested. 6. Construct storage units so that they are tight and can be cleaned easily. 7. Store bulk materials, such as pet foods, in containers with tight-fitting lids. 8. Keep storage units dry. THIS IS IMPORTANT. Moisture favors the de- velopment of pantry pests; dryness dis- courages them. Many pantry insects breed in the nests of rodents and insects and may migrate from these into homes. Dumps and areas where by-products and wastes from processing plants are deposited afford excellent breeding places. Opened food products which are set aside and forgotten are almost certain to become infested. Once the product has been wholly or partially consumed, the insects disperse and— if general feeders- may soon infest every suitable material in the house. If not eradicated, the pest may become so abundant as to literally swarm, crawling on floors, climbing up walls, and gathering about windows. Most infestations in the home result from carrying in the pest on some in- fested product. Most food product pack- ages are relatively insect-tight and, unless the products were infested when origi- nally packed, they should remain free of pests. PREDACEOUS & DARKLING GROUND BEETLES Tule beetle, Platynus maculicollis (Dej.) Among the insects that live outdoors but accidentally enter homes while seek- ing a place to hibernate or estivate (pass the summer in an inactive state) are the predaceous ground beetles and the dark- ling ground beetles. These do no harm in the home other than emitting a very offensive odor. Predaceous ground beetles are somber brown, medium-sized beetles that move rather rapidly and feed on other insects. One of the most troublesome of the species is the tule beetle, which is about % inch long, pale brown in color with a small darker blotch in the middle of the prothorax (first segment bearing legs) and a larger, darker blotch occupying much of the wing covers. It breeds in the [25 marsh lands along rivers and often ap- pears in large swarms at dusk following rains in the fall. The darkling ground beetles are small, hard-shelled, dark-brown, slow-moving beetles that feed on decayed vegetable matter. Among insects which may be confused with predaceous and darkling ground beetles are wood-boring beetles which emerge from small holes in infested fire- wood brought into the house. These pests may congregate in large numbers on windows, but will do no harm. Control measures are the same. Homes located under oak trees may be invaded by tiny, grublike weevil larvae. These develop inside acorns and, when mature, leave the acorns and drop to the ground to pupate. If they land on the roof of a house instead, they may crawl into the dwelling. Birds may cache in- fested acorns about a house, and the grubs that emerge from these may also be encountered. What to do: If only a few insects are involved, kill them with a flyswatter, Larger numbers may be controlled with contact sprays or dusts. Direct the insec- ticide to the areas where the pests con- gregate. Contact spray solutions are in- flammable; see page 6 for precautions. To prevent entry of the beetles, seal all openings and crevices in the outer walls of the house, particularly the cracks between doors and door jambs. Make sure screens are tight. Eliminate all rubbish and other accumulations about the foun- dation. Keep the outside of the house dry and prevent shrubbery from growing over windows or other openings. Proper prun- ing and training of vines and shrubs that grow over buildings is of value. Do not confuse the relatively harmless beetles with the damaging carpet beetles and pantry beetles which may "swarm" in various parts of the house. Control methods for these different types of beetles are not the same. PSOCIDS Cereal psocid, Liposcelis divinitorius (Mull.) Psocids (booklice) are tiny, soft- bodied, flattened insects scarcely as large as the head of a pin. Those found in the house are wingless and light to dark in color. Usually they are not harmful, but become annoying when they increase to large numbers under favorable condi- tions. Warmth and dampness favor the pest, and it is most likely to be found in dark, damp rooms or among damp vegetable products such as occur in straw mat- tresses, certain upholstered furniture, wallpaper, and pantry supplies. They may thrive in new houses or buildings that have not had sufficient time to dry thoroughly. They may be recognized by the jerky manner in which they run. Their food appears to be mostly microscopic molds which occur in and about a house under certain conditions. They may damage bookbindings and other starchy mate- rials. What to do: Spray places where psocids are found with a 5 per cent DDT spray. DO NOT use such a spray near flames of any kind; see page 6 for other precautions. Dry out the areas where psocids are found. See that the environment is well ventilated and exposed to as much light as possible. Heating houses during periods of fa- vorable temperature conditions in the summer will help. Raise the temperature [26] to 125 degrees F and maintain it for at least 12 hours. Destroy infested materials if they are of little value. Otherwise, thoroughly dry them, or fumigate them in the manner de- scribed on page 24. SCORPIONS SILVERFISH & FIRE BRATS Scorpion, Hadrurus hirsutus (Wood) Scorpions are easily distinguished by their crablike appearance plus a long, fleshy tail ending in an enlarged tip bear- ing a stinger. The stinger is normally used to paralyze the insects and spiders upon which the scorpions feed. The sting of most scorpions is quite painful, but no more to be feared than the sting of a wasp. The dangerously ven- omous types of scorpion are not known to occur in California. Scorpions found in California measure from less than 1 inch to over 3 inches in length. They usually move about at night, hiding during the day under floors, boards, and debris, or the bark of trees. What to do: Spray clear creosote on joists and subfloor supports of buildings and on the ground under buildings. This will kill any pests contacted and seems to repel future invaders for an indefinite period. Also spray rough outbuildings such as privies and garages. Eliminate accumulations of debris, stacks of lumber, or stored household effects from basements or places adjacent to the house. These serve as hiding places for the pest. If you live in an area where scorpions are abundant, shake clothing and inspect shoes before dressing. Silverfish, Ctenolepisma urbana Stabaugh Silverfish, Lepisma saccharina Linn., and fire brats, Thermobia domestica (Pack.), are long, wingless, scaly insects about % inch in length. They are noc- turnal, fast runners that can be recog- nized by their pair of long antennae and 3 prominent filaments that protrude from the tail end. Silverfish, which are silvery-gray in color, prefer warm, damp places, but may be found in almost any part of a build- ing. Fire brats, which are mottled with dark spots, are more warmth-loving and usually stay in heated basements or simi- lar locations. Both are hardy insects and can live for long periods without feeding. The food of silverfish consists mostly of vegetable matter, preferably foods having a high starch or sugar content. Such foods as moist wheat flour are particularly favored. The insects become very destructive under favorable conditions by feeding on the sizing in paper, bookbindings, wall- paper, or any other materials where glue or starch are present. Fabrics of plant origin are attacked in varying degrees. Thin starched materials, linen, and rayon goods may be seriously damaged, while lisle and cotton fabrics are also fed upon. Clean fabrics of animal origin are prac- tically avoided. What to do: Apply a 5 per cent solu- tion of DDT in highly refined kerosene as a coarse spray on surfaces frequented by the pest. These include the back walls [27 of shelvings, baseboards, closets, dead spaces under sinks, and holes where pipes pass through floors or walls. DO NOT use spray near fires or flames of any kind; see page 6 for other precautions. Attics and basements should be sprayed if pests are found there, but dusting with a 10 per cent DDT dust is usually more convenient. Poison baits have been used to control these pests, but have been rather completely replaced by DDT. Household solutions that contain chlor- dane or lindane are also effective against silverfish. To prevent breeding of the pests, dry out the warm, damp, secluded locations that foster their development. SOWBUGS & PILLBUGS Pillbug, Armadillidium vulgare (Latr These organisms are dark or slate in color with flattened, segmented bodies and 7 pairs of legs. They breathe by means of gills and will die if not moist. Therefore, they live in damp earth and leaf mold, and rapidly disappear during hot weather if their habitat thoroughly dries out. Although sowbugs and pillbugs will feed on almost anything, their diet con- sists chiefly of decaying vegetable matter. They will attack living vegetation and are particularly injurious to seedlings. They sometimes become household pests when they congregate in large num- bers in a moist basement. What to do: Apply a contact insecti- cide containing DDT directly on the pests and on areas they frequent. Seal all cracks and openings through which they may enter the house, especially around win- dows and doors. Contact sprays are in- flammable; see page 6 for precautions. Remove rubbish and other accumula- tions about the foundations. Prevent shrubbery from growing over windows and other openings. Keep the outside of the house dry. SPIDERS Black widow spider, Latrodectus mactans (Fabr.) Spiders may be distinguished easily from insects in that they have 4 pairs of legs instead of 3 and do not have anten- nae or feelers. The only spider in Califor- nia that is definitely poisonous to man is the black widow, Latrodectus mactans (Fabr.) . Most of the other species found in the home do more good than harm. The adult female black widow has a rounded, glossy black body, and is often known as the shoe-button spider. Usually there is an orange or red marking re- sembling an hourglass on the underside of the body. The shape of the mark is not constant, however, and some spiders may have more than one mark. The adult female is most often encoun- tered. With legs extended, it measures up to 2 inches in length. The male is much smaller and has stripes of white and pale brown along the sides of the abdomen. The loose irregular web constructed by the black widow is found in protected, dark corners of garages, basements, and outhouses, and under piles of wood or [28 rubbish. Its silken strands are quite coarse in comparison with those of other house spiders. The life cycle of the black widow spider requires at least 4 months. After being fertilized, the female spins a cuplike structure of silk and suspends it in her web. In this she deposits from 20 to sev- eral hundred eggs, then caps the cup and winds silk about it. Nine or more of these oval egg sacs may be constructed during the life span of one female. The Pholcus spider, encountered in basements, closets, and other dark places, spins irregular, loose webs which are often mistaken for those of the black widow. However, the web is of much finer silk. The spider has an elongate body with very long legs and has a habit of violently shaking its web. Trapdoor spiders are rather large and are often mistaken for young tarantulas. They build tunnels in the ground and cap them with lids of soil and silk. They are often found wandering in and around homes following the start of the rainy winter season. The spiders commonly called tarantulas in California are found most abundantly in the southern part of the state. They are very large, hairy, ferocious-looking spiders, but are practically harmless to man. They are only accidental visitors in a home. Also harmless are spiders of the orb weaver group, which spin symmetrical rounded webs in gardens. There are many other innocuous species of spiders invad- ing houses which can normally be con- trolled by good housekeeping methods. In the case of unusual infestations, how- ever, the following control methods sug- gested for the black widow may be used. What to do: For black widow spiders treat garages, basements, attics, and out- houses with a residual spray of DDT or lindane. Wet the walls and webbing with spray along beams, in cracks and corners, and under shelves or similar protected sites which are most frequented by the spiders. Such sprays are inflammable; see page 6 for precautions. The spray will kill spiders contacted and will continue up to several months to kill spiders visiting the treated surfaces. The following spray formulations are ef- fective : 1 . 2% ounces of 50 per cent wettable DDT per gallon of water. 2. 1 ounce of 25 per cent wettable lin- dane per gallon of water. 3. 2 per cent water emulsion of DDT. 4. 0.4 per cent water emulsion of lin- dane. Creosote has also been used success- fully in treating the wood of outhouses, killing spiders and repelling future in- vaders. To prevent entry of spiders, tightly screen doors, windows, and other open- ings of the house from basement to attic. Destroy weeds, rubbish, and dead grass in the yard and clear away rocks, tin cans, and other debris which might pro- vide shelter for the black widow spiders. TRIATOMA BUGS Triatoma bug, Triatoma protracta (Uhl) Triatoma bugs (known also as China bedbugs, cone-nosed bugs, or kissing bugs) live exclusively on the blood of ani- mals, including man. They frequently at- tack sleeping persons at night, sometimes without being detected or causing after- effects. However, some persons are ex- tremely sensitive to their bites and may experience an intense itching, nausea, flushed face, palpitation of the heart, rapid breathing and pulse, and hives. [29] The adult bugs vary in color from very light to dark brown and vary in length from % to iy 2 inch. They have a long, narrow head with a slender, piercing beak which is bent beneath the head when not in use. The wings are folded back over the body and overlap at their tips, leaving a triangular area between the bases. The immature bugs are similar to the adults but do not have wings and are considerably smaller. The bugs live in the nests of wood rats (Neotoma, pack rats, etc.), but will also be found invading the beds of human beings. In California they sometimes are found flying to lights and at such times they may fly in the open windows or doors of houses. These bugs have been found naturally infected with the parasite causing Chagas disease in man, but no human cases have been reported in the state of California. What to do: Spray directly with a standard fly spray or an aerosol bomb. This will kill only those insects present at the time. Application of DDT as a residual spray or as a dust has not proved effective in tests conducted at the University of Cali- fornia. Residual lindane sprays prepared as described for fly control (page 18) will provide several months' protection when applied to interior walls and floors. The material is safe to use, but the slight, lingering odor is offensive to some persons. There is no specific treatment for the bite of these bugs. Warm compresses of magnesium sulfate applied to the bite are recommended. If the symptoms are se- vere, call a doctor. To prevent invasions by Triatoma bugs, screen your house and make it insect-proof. Remove the nests of wood rats from the neighborhood of dwellings, especially from underneath the house. Wood rats sometimes nest under houses, but more often they nest in piles of cactus pads or mesquite in desert regions or in piles of sticks in forested areas. TROPICAL RAT MITES Tropical rat mite, Bdellonyssus bacoti (Hirst) The tropical rat mite, Bdellonyssus bacoti (Hirst), is most frequently en- countered in California homes after the rat on which it lived has left the premises or been destroyed. At such times the hungry mites may swarm over the walls and furniture seeking a blood meal. They are most obvious immediately after feed- ing when their normal gray-brown color is overshadowed by the red of ingested blood in their swollen bodies. Their tiny size— up to %oo mcn m length— often results in their escaping de- tection and insects such as fleas being suspected as the cause of annoying bites. Their bites cause an inflammation of the skin, known as "rat-bite dermatitis," and are usually accompanied by intense itch- ing. There may be watery blisters or a slight to moderate swelling. In children particularly, the effects of the bites are more noticeable, and scratch- ing creates the danger of subsequent bac- terial infection. The mite may transmit endemic typhus to man. What to do: Eliminating rats from the house is the primary necessity. If the rodents are known to be infested with tropical rat mites, spray the building thoroughly with highly refined kerosene containing lethane. A thorough spraying with refined kerosene alone will kill those mites contacted, as will wiping furniture with a rag soaked in refined kerosene. Such use of kerosene constitutes a fire hazard; see page 6 for precautions. Various other commercial household spray preparations are effective, but se- vere infestations may require fumigation of the house with hydrocyanic acid gas by a licensed pest control operator. [30] WASPS & YELLOW JACKETS Yellow jacket, Vespula pennsylvanica (Saussure) There are several kinds of wasps that at times are very annoying to man: yel- low jackets or hornets such as the Vesp- ula species, Polistes wasps, and mud- dauber or thread-waisted wasps such as Sphex and Pelopaeus species. Outside of what annoyance they cause and what fruit they may eat, yellow jackets are beneficial because they de- stroy enormous numbers of insects. They construct large paper nests from fibers obtained from plant sources such as bark or weather-worn wood and from non- natural sources such as paper. The fibers are made into paper by chewing and mix- ing with saliva. The nests are enclosed in envelopes of several layers. Some yellow jackets build their nests above the ground, while others construct them in the soil. Control measures de- scribed below vary according to the loca- tion of the nest. Three kinds of individuals are found in the nests: queens, males, and workers. Only the queen overwinters, and she leaves the nest to hibernate under bark or in other protected places. In the spring she starts the nest and rears the first brood, after which the workers take over the rearing, feeding, building, and caring for the nest. Once this occurs, the nest rapidly in- creases in size. Sexual forms are pro- duced during the summer and fall. New queens and males are produced earlier in the season in colonies of those species that nest above ground than in colonies of those that nest in the soil. Once pro- duced, the sexual forms leave the nest and mate, and the new queens seek hiber- nating quarters. The old queen dies, and the nest begins to decline. Workers left in nests built above ground always die before the advent of cold weather, while those that nest in the soil may live on into the winter. This is another factor to be remembered in choosing control measures. Adult yellow jackets feed only on liquids, and eat principally energy-yield- ing foods such as nectar, honeydew, juice (and pulp) of ripe fruit, and manu- factured sweets. The larvae are fed ani- mal materials such as soft-bodied insects and meat, which are first chewed and con- ditioned by the workers. Polistes wasps normally do not attack man. Their life history and habits are very similar to those of yellow jackets, except that their colonies are much smaller and their open-faced, paper nests are not enclosed in envelopes. The nests seldom measure more than 3 inches in diameter. The queens are the only mem- bers that overwinter and sometimes be- come annoying by entering homes to hibernate. Mud-dauber or thread-waisted wasps are solitary wasps that seldom attack man and can be distinguished from other wasps by the long narrow waist between the thorax and abdomen. They construct their nests of mud, and the winter is passed as mature larvae in earthen cells. There is only one generation a year, with mating occurring in the spring. The females construct earthen cells, and most common forms fill them with paralyzed spiders. An egg is deposited in each stocked cell, which is then sealed. No further care is needed, in marked con- trast to other wasps whose young are fed conditioned food by the workers. What to do: For those yellow jackets that build their nests above the ground, no control measures are necessary after [31] mid-summer or shortly thereafter. By that time the nests will be deserted. If the nuisance occurs before that time, spray the entrance to the nest with a good contact spray, such as a 5 per cent DDT solution. Such sprays are inflammable; see page 6 for precautions. The treatment should be applied in the evening. Any wasps that fly out will be incapacitated as soon as they strike the spray, so there is little danger of the operator being stung. A time-honored and effective method of control consists in enveloping the nest with a drawstring bag at night, then soaking with kerosene or scalding water. The nest readily absorbs the spray, so apply enough material to thoroughly wet it. It can be removed the following day. Effective control can also be obtained by thoroughly dusting the entrance to the nest with a 10 per cent DDT dust or one that contains chlordane. Yellow jacket nests found in the soil should be attacked at night by pouring 1 to several ounces of carbon disulfide into the entrance and covering with sev- eral shovelfuls of soil. This should result in the elimination of the colony. Carbon disulfide is very inflammable and explosive when mixed with air. Keep it away from flames and sparks of all kinds, and use with great caution. DO NOT store it in the house. A 10 per cent DDT dust, or one con- taining chlordane or lindane, is also effective against ground nests. Apply the dust after dark with a small hand duster. Approach the nest cautiously in order not to disturb the yellow jackets within, but get close enough to direct the dust into the opening. Polistes wasps are easily controlled by spraying the nest after dark with a good contact insecticide or dusting it with a 10 per cent DDT dust. If found hiber- nating in the house, they can be killed by spraying the locations they frequent with a 5 per cent DDT solution. DO NOT use such a spray near flames of any kind; see page 6 for other precautions. Since there is only a single individual to contend with in controlling the mud- dauber or thread-waisted wasp, kill it with a flyswatter or a contact spray and destroy the nest. The nest can be de- stroyed when the individual is seen to leave it. In winter destroy the mud nests to eliminate the overwintering forms. [32] In order that the information in our publications may be more intel- ligible it is sometimes necessary to use trade names of products or equip- ment rather than complicated descriptive or chemical identifications. In so doing it is unavoidable in some cases that similar products which are on the market under other trade names may not be cited. No endorse- ment of named products is intended, nor is criticism implied of similar products which are not mentioned. [33 INDEX OF INSECTS DISCUSSED IN THIS CIRCULAR INSECT Page INSECT Page INSECT Page Ants 7 Clothes moths 13 Pantry beetles 23 Argentine 7 Clover mites 14 Pavement ants 7 California fire 7 Cockroaches 15 Pharaoh's ants 7 California velvety tree 7 American 15 Pholcus spiders 29 Odorous house 7 Australian 15 Pillbugs 28 Pavement 7 Brown-banded 15 Polistes wasps 31 Pharaoh's 7 German 15 Predaceous ground Pyramid 7 Oriental 15 beetles 25 Tiny black ant 7 Cone-nosed bugs 29 Psocids 26 Western thief 7 Confused flour beetles 23 Pubic lice 20 American cockroaches 15 Cooties 20 Pyramid ants 7 Australian cockroaches 15 Corizid grass bugs 8 Rice weevils 23 Bean weevils Bedbugs 23 8 Crab lice Crickets 20 16 Sarcophagids Saw-toothed grain 18 Beetles Darkling ground beetles 25 beetles 23 Carpet 10 Drugstore beetles 23 Scorpions Shoe-button spiders 27 Confused flour 23 False stable flies 18 28 Darkling ground 25 Fire brats 27 Silverfish 27 Drugstore 23 Fleas 16 Sow bugs 28 Pantry 23 Fleshflies 18 Spiders 28 Predaceous ground 25 Flies 17 Black widow 28 Saw-toothed grain 23 Flour moths 19 Orb weaver 29 Tule 25 German cockroaches 15 Pholcus 29 Wood-boring 26 Granary weevils 23 Shoe-button 28 Bird-nest carpet beetles 10 Greenbottles 18 Tarantula 29 Black blowflies 18 Head lice 20 Trapdoor 29 Black carpet beetles Black widow spiders Blowflies 10 28 House centipedes 12 Stable flies 18 18 Houseflies 17 Tarantulas 29 Bluebottles 18 Human fleas 16 Thread-waisted wasps 31 Body lice 20 Indian meal moths 19 Ticks (dog) 9 Book lice (psocids) 26 Kissing bugs 29 Tiny black ants 7 Box elder bugs 8 Latrine flies 18 Trapdoor spiders 29 Brown dog ticks 9 Lesser houseflies 18 Triatoma bugs 29 Brown-banded Lice 20 Tropical rat mites 30 cockroaches 15 Body 20 Tule beetles 25 California fire ant 7 Book 26 Varied carpet beetles 10 California velvety Head 20 Wasps 31 tree ant 7 Pubic 20 Mud-dauber 31 Carpenter ants 7 Meal moths 19 Polistes 31 Carpet beetles 10 Millipedes 21 Thread-waisted 31 Casemaking clothes Mosquitoes 21 Yellow jackets 31 moths 13 Mud-dauber wasps 31 Webbing clothes moth; i 13 Centipedes 12 Orb weaver spiders 29 Western thief ants 7 Cereal mites 13 Oriental cockroaches 15 Wood-boring beetles 26 China bedbugs 29 Odorous house ant 7 Yellow jackets 31 [34 Cooperative Extension work in Agriculture and Home Economics, College of Agriculture, University of California, and United States Department of Agriculture cooperating. Distributed in furtherance of the Acts of Congress of May 8, and June 30, 1914. J. Earl Coke, Director, California Agricultural Extension Service. 50m-4,'51(3701)HSC JbfctffeA *££4<itoL±mljJ&&l WATER SUPPLY AND SALT LICK HE PHOTO above is taken from a circular on irrigated pastures in California. It shows a good lay- out of fences and gates for rotation grazing. The drawing below cular on selective weed killers and shows one reason why some weed killers are selective. These pictures are typical of the practical, down-to-earth approach SPRAY BOUNCES OFF CEREAL LEAVES SPRAY STICKS TO WIDER, HORIZONTAL LEAVES to farm problems used in many of the free publications put out by the University of California College of Agriculture. n editing thes e is: tell itsimpl simply, use a photograph; if a pho- tograph won't show it, draw a pic-( ture. The publications cover a wide va riety of farm subjects, and their aim is to present useful information de- veloped by the University's spe- cialists, in a clear, easy-to-read manner. Perhaps one or more of these publications will help YOU with your farm problems. For a catalog listing all of the publications available, see your County Farm Advisor or write to: OFFICE OF AGRICULTURAL PUBLICATIONS, 22 GIANNINI HALL, UNIVERSITY OF CALIFORNIA, BERKELEY 4, CALIFORNIA