Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. UNITED STATES DEPARTMENT OF AGRICULTURE MISCELLANEOUS PUBLICATION NO. 526 Washington, D. C. Issued November 1943 INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS ON ~ FRUITS AND VEGETABLES Esler N. F. HOWARD and C. A. WRIGEE .!\ By Senior Entomologists, Division of ck Crop ad mr 40 } 4 a Garden Insect Investigat Dgy JRIWN C. M. SMITH Senior Chemist, Division of Insecticid Inzes tigations: | OF s and aes L. F. STEINER Entomologist, Division of Fruit Insect Investigations Bureau of Entomology and Plant Quarantine Agricultural Research Administration For sale by the Superintendent of Documents, U. S. Government Printing Office Washington, D.C. - Price 10 cents UNITED STATES DEPARTMENT OF AGRICULTURE Miscellaneous Publication No. 526 Washington, D. C. Issued November 1943 INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS ON FRUITS AND VEGETABLES By N. F. Howarp and C. A. WEIGEL, senior entomologists, Division of Truck Crop and Garden Insect Investigations, C. M. SMirH, senior chemist, Division of Insecticide Investigations, and L. F. STEINER, entomologist, Division of Fruit Insect Investigations, Bureau of Entomology and Plant Quarantine, Agricultural Research Administration. CONTENTS Page Page RTUtTOGHCIIOTA- Se tee noe ee ne Da aACO IO PEN LORILGs ses 2 Ise 24 Precautions in using insecticides_____________- 2 | Nicotine decoctions (home-made)_____________ 24 Spray residuesion plants 29) 2 eS SF bi TTS PS 5S AN ee 24 Injury to the plants by insecticides__________- 4 Nicotine for fumigation______________________ 25 Le CES EEUU CH Hg COC CSS sR UNO MES ES! Henge to cee En eS 26 TED SCE 2 ea ay Oe ojjebaradichlorobenzené_ 2 =.= 26 Basaran eS CMY GEE MISS CoC) i as i ot ee See 27 Barm' igosilicatese— a Oke DENOLMINGINIGR See os i oe 27 ani Gia pee ee eee ie Mw Ot Bae nespuGruds Waste 22 tas co a 28 Bepamiapnthal ot = pe eee ee EE Gi OISOHed Palisa ees eS Se 28 Bomleatexmixiroe ee ee EP, 6 | Pyrethrum, or insect powder___._____________ 29 GOR POTEET Eu aol: | a a a 8 | Rotenone-containing roots____________________ 30 Walemimepyanide +! 54. - soe eh 8 EY es 8 Restrictions on the use of rotenone in the CINE Serer PEST tC Fe Sa eee 9 contnol efimspets <<... --.) 2) 2 ee Sia a Ne Se SLURS OST OF Ags eee le A a 33 REACT Fie Seat lea ee ey en ee ee eae 11 | Sodium arsenite___________ St ees 33 Ei thet pn tea iy EE ae POU CURING 2 fern wer 33 ARTA en eee: et or ee 8 Sr seat peGiamd nenmde=s. 555 22s rt 34 aldentacor. carverss< 2200) S22 a BAGH SOGiaTma TUOSIICALO. 2. 35 Poin ANTI ee ee ese ee ee oe See 35 LORS TCA UNO ESS ea se ee es Pees MAI PRIN CUES UPR fie Cee ee 35 Bihvieneaichloride. 2.) Deir peru <2 oe On ee es 36 EAN Qi ts eer Ce es ie Ree it 13 | Thiocyanates (organic) -_____________._______. 36 LEVI een cee ee 2 eh anal Gee Ds, So i a LENA R cre? SAN 2 25 See are SS 37 Ou-weten ironument o: i) an a Jin] id as eee oe Cr ist 2 es na ee a 37 PiyGraiod itm: 2, ee tent tes Ae EM ae Be Re eed oo ae 37 Puerta IOTITINI GA Soe Gk) 15 | Wetting or spreading agents__.__.____.______- 37 iead prsanebe (acid ie. oo 8 se ie BBN eG END ee Ds 3s Diam armament Desi) = 2s 17 | Preparation of sprays and dusts____..________- 38 Liquid lime-sulfur and dry lime-sulfur_______- 17 | Quantity of sprays or dusts to apply_________- 39 Peete rt Ernie a8 8 oe Go 18 | Spraying and dusting equipment____________- 42 Reem an Ibies ee a 18 | Care of insect-control devices_______-_________ 50 RGHATEOHS GhIDMNGG 8 ee S05. 19} When and how to apply insecticides_________- 51 Metaldehyde (slug bait)____..___.__.._______. 19 | First-aid suggestions in cases of insecticidal ait go een TSE On tae 8 SS eS a eee aie 51 Le tr AS Raed ae ae ee 20 | Procurement of insecticides and subsidiary OS Cee ie ee ee ae 22 TRRLGRION ee 2 es 52 io Cae ie Ee SSE eee 23 1 Z MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE INTRODUCTION Adequate food supplies have an essential place in the successful conduct of the war. Insects should not be permitted to reduce the increased yields required to supply necessary food. The national effort to increase food production necessitates that those who serve as advisers in the Victory Garden programs be informed on the sources, supplies, and uses of the chemicals, or insecticides, needed to control insect pests. This publication has been prepared for this purpose. It will be useful, also, to market gardeners, fruit growers, nurserymen, florists, and others concerned with the control of insects by insecticides. Specifically, this publication deals with the nature of the chemicals more commonly used to control insects on fruits, vegetables, and flowering plants, and gives information on how to prepare such insecticides for use against many common pests. A section is devoted to a discussion of spraying and dusting equipment. Most insecticides will become scarce as stocks are depleted and re- placement becomes difficult. It is not only thrifty, but patriotic as well, to use them carefully. Careful application of minimum amounts will do a better job than careless use of large quantities. The aim should be to mix the material thoroughly and apply it as a light, even coating to the parts of the plant affected by the insect. Applying the material to the parts affected saves material and insures effective control of the pest. For more specific Information on the control of any pest, the entomological publications of the State or Federal Government, or a State or Federal entomologist, or an entomologist of some other organization, should be consulted. If the pest is not identified, pre- served or dead specimens of the insect or a description of its injury should accompany the request for information on control. PRECAUTIONS IN USING INSECTICIDES Most chemicals used as insecticides are poisonous to man and other animals and should be handled accordingly. When mixing or applying insecticides, take extreme care to keep the materials out of the mouth and eyes and away from tender parts of the body. When spraying or dusting operations are long and con- tinuous, keep the body well covered, even in the warmest weather, and wear goggles to protect the eyes. Small quantities of spraying or dusting materials which come in contact with the hands or body will be of little consequence, but accumulations of such materials resulting from long exposure are harmful. In any event, wash the face and hands thoroughly after using any insecticide. After long exposure it should be the practice to take a bath and change the clothes, and this should be done both at noon and after the day’s work. Residues should not be per- mitted to accumulate on clothing. To avoid this, the clothing used in spraying operations should be washed frequently. Containers in which insecticides are stored should be plainly marked “Poison” and the date of purchase shown. They should be kept tightly closed and in a specially selected place, preferably INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 3 under lock, and well out of reach of children and others unfa- miliar with their poisonous nature. Every effort should also be made to prevent domestic animals and livestock from being poi- soned by insecticides, either through feeding on treated vegeta- tion, licking containers, or drinking water which may have been contaminated. To aid in avoiding poisoning from the accidental use of white insecticides, some of them, particularly lead arsenate, calcium arsenate, and sodium fluoride, are now colored by the manufacturer. Containers in which materials are being mixed or batches of pre- pared insecticides set aside for the moment should not be left open or exposed in such a way that roaming farm animals, in passing, can lick them. Empty packages and bags should be buried or burned. Un- used portions or discarded material should be buried at least a foot below the surface and away from water supply or drainage. Horses, cows, sheep, and poultry should be prevented from feeding or grazing under trees that have been sprayed. Water from roofs that have been sprayed accidentally may also be a source of danger. SPRAY RESIDUES ON PLANTS Residues of insecticides on the harvested product may endan- ger the consumer’s well-being and must be guarded against. The recommendations that follow are given as a guide in avoiding such risks. Inorganic insecticides, such as the arsenicals and fluorine compounds, should not be sprayed or dusted on the edible foliage or fruit when the residues on the part used for food cannot be removed, either by washing or wiping, or by stripping off the outside leaves. These materials should not be applied to strawberries within 3 weeks of harvest, or to grapes and bramble fruits after the blossoms have opened and the berries have begun to form. Treatment after such time may leave dangerous quantities of residues on the harvested berries. Fruits such as apples may be washed in weak acid or alkaline solu- tions to remove excessive deposits. Unless they are to be washed in a manner that will remove excess amounts of insecticides, apples should not be sprayed with arsenicals or fluorine compounds after June. The Federal Government prohibits the movement and sale of apples and pears in interstate commerce when residues of lead, arsenious oxide, and fluorine exceed certain prescribed limits. For lead the tolerance is 0.05 grain Pb per pound of fruit, for arsenic, 0.025 grain As,O; per pound, and for fluorine, 0.02 grain F per pound. Insecticidal residues cannot be removed satisfactorily from cabbage, lettuce, celery, spinach, cauliflower, turnip greens, kale, broccoli, or other greens by a superficial washing of the head or leaves. Such a washing may remove the residues from the outside smooth surfaces of the leaves or fruit, but the innermost parts among the folds or ribs will not be affected materially. Cabbage.—Such materials as paris green, cryolite, and calcium arsenate should not be applied to any portion of the cabbage plant that is to be marketed. This means that cabbage intended for marketing as U. S. Grade No. 1 (which allows four loose outer leaves) should 4 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE not be sprayed with these materials after the head has begun to form. If the marketed product is to bear a greater number of loose outer leaves than those allowed in U.S. Grade No. 1, these materials should not be used after the plants have been thinned or transplanted. If all the outer leaves of headed cabbage have been removed, the re- ~ mainder should be free of harmful residues. — Celery—Arsenicals and fluorine compounds are not recommended for use on celery because of harmful residue. . Tomatoes.—Residues may occur on tomatoes treated with calcium arsenate or cryolite, but the washing process in the canneries and wip- ing the fruit for market with a cloth will practically eliminate these residues. Beans.—¥ or green and snap beans, sprays or dusts containing cryo- lite or arsenicals should not be appled after the pods have begun to form. If treatment is made after this period of growth, two or three washings of the harvested beans in water should remove any harmful residues. Peppers——All peppers that have been treated with an arsenical (calcium arsenate) or fluorine compound (cryolite) must be washed before they are marketed or processed. INJURY TO): THE PEANTS BY-INSECTIGCIDES Insecticides, especially when improperly prepared or applied, may injure the plant foliage and flowers. Promiscuous spraying is there- fore very inadvisable. Insecticides are seldom if ever beneficial to the plant itself, and they are good and useful only insofar as they remove the dangerous and destructive pests with a minimum of damage to the plant. The choice and purity of the materials and the care exercised in their preparation and application influence the results obtained. The margin of safety between the effective dosage required to kill the insect and the tolerance of the plant to the insecticide is often very narrow. Some plants will tolerate more insecticides than others; for example, beans are likely to be damaged by treatment with arsenicals, whereas potato and cabbage will withstand comparatively large dosages of such materials without injury. The factor of plant tolerance, therefore, as well as the effect of the insecticide on the insect, must be considered in pest control. Oftentimes the plant tolerance limits the general use of an insecticide. For example, lead arsenate and calcium arsenate will control the Mexican bean beetle, but under certain climatic conditions both these materials may cause plant injury. Magnesium arsenate, while satisfactory on beans under most conditions, will cause plant injury to peach and apple trees. Hydrated lime is used with the arsenicals as a means of offsetting foliage injury; but it should not be used with the fluorine compounds, with which it is not compatible. . Sulfur, applied either as a dust or a spray, may cause injury to the foliage of squashes, melons, and cucumbers, and to the fruits of raspberry, as well as to the tender growth and blossoms of roses and various other flowering plants. Many plants will not tolerate oil. sprays, especially when repeated applications are necessary. a INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 5 Rotenone- and pyrethrum-containing sprays and dusts, and helle- bore, are tolerated by most plants and rarely cause injury. Either sodium fiuosilicate or barium fluosilicate, even when diluted with five times its weight of clay as for the control of blister beetles, will cause injury under some conditions, and many plants will not tolerate them. Cryolite applhed at the recommended dosages is nor- mally tolerated by most plants, but corn is particularly sensitive to this material as well as to other fluorine compounds. Sodium fluoride should not be used as a plant insecticide, as it may destroy the plant. Soap sprays, especially when used at high concentrations, will in- jure the leaves of such tender plants as young cabbage or cauliflower in seed beds, or garden peas and young beans, as well as many tender ernamental plants. The dosages of insecticides recommended in this publication are based, in general, upon the minimum quantities that will contro] the insects and that are within the range of dosages the plants will tolerate. ARSENIC TRIOXIDE Arsenic trioxide (As.O,), or arsenious oxide, is a crystalline ma- terial usually sold as “white arsenic.” It is largely obtained as a by- product in the flue dust from smelters. In normal times our supply comes from both domestic and foreign sources. In somewhat impure forms it is marketed as off-white arsenic under names indicating its color, such as gray arsenic. Arsenic trioxide is the starting material in the manufacture of the arsenical plant insecticides such as lead arsenate and calcium arsenate. Because of its adverse effect upon plant tissue it is not used as a plant insecticide, but is used in the compounding of poisoned baits for the control of grasshoppers and cutworms and certain other insects. (See Poisoned Baits, p. 28.) Caution.—Arsenic trioxide is a violent poison and must be stored in a safe place and in plainly labeled containers. The powder should not be inhaled, and it should not be permitted to come in contact with the skin, especially open wounds. BARBASCO See Rotenone-containing Roots (pp. 30-32). BARIUM CARBONATE Barium carbonate (BaCO,), a domestic, natural, chalklike sub- stance, is ground to a powder and used as an insecticide in some cases, but it is better known as a rat poison. Rather heavy dosages are required to protect plants from attack by chewing insects, such as the Mexican bean beetle (14 pound to the gallon of water). Caution.—Barium carbonate is poisonous to man and animals when taken into the intestinal tract, and care should be exercised in handling it. BARIUM FLUOSILICATE Barium fiuosilicate (BaSiF,), a domestic product, has been used against some insects. While somewhat useful in the control of the 6 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE Mexican bean beetle, when used at the rate of 6 pounds to 100 gallons of water, it is of more value against flea beetles and blister beetles. It may cause foliage injury. To reduce foliage injury, alkaline waters and those containing sulfates should not be used with this material. Caution.—Barium fluosilicate is very poisonous to higher ani- mals and man. Observe care in its use. For spray-residue tolerance see page 3. : BENTONITE Bentonite is a naturally occurring, light-colored clay. Chemically, it is chiefly a hydrous silicate of aluminum, calcium, and magnesium; but a variety of other compounds may be present, depending upon the source of the material. . There are two general classes of bentonites, the swelling and the nonswelling. The former is used to dilute insecticidal and Fim eadal dusts, as an emulsifier for home-mixed oil emulsions, and in the prepa- ration of tank-mixed and proprietary nicotine bentonite sprays. The principal source of the swelling type is the Black Hills region of Wyoming and South Dakota, and the name “Wyoming bentonite” is generally used to distinguish it from nonswelling clays. When wet it will absorb water and swell to from 7 to 11 times its dry volume, forming a gelatinous mass. Most of the bentonites, both the swelling and nonswelling types, will react with nicotine to form a nicotine bentonite in which most of the nicotine is insoluble in water, so that the combination acts as a stomach poison rather than a fumigant or contact insecticide. At present Wyoming bentonite is preferred for use with insecticides. It is obtain- able either as a fine powder, which is preferred when used as a diluent, or in fine pellets for use in making tank-mixed oil emulsions or nico- tine-bentonite sprays. (See Nicotine Bentonite, a/so Mineral Oil.) BETA NAPHTHOL Beta naphthol (C,,H-OH) isa slowly volatile, crystalline compound that is used to impregnate corrugated paper bands, ftr placing around the trunks of mature apple trees to trap and kill codling moth larvae. Rolls of single-faced corrugated paper 2 inches wide may be dipped in a hot (250° F.) solution of 1 pound of beta naphthol (technical) in 1.5 pints of lubricating oil having a Saybolt viscosity of 100-300 seconds at 100° F. The mixture can be used cold if diluted with gaso- line. The chemical coating should be from 0.3 to 0.5 ounce of beta naphthol plus oil per linear foot of band, the smaller quantity being used in the Pacific Northwest. Some persons with a delicate skin are very sensitive to beta naph- thol and may experience a burning sensation when working with it, but the effect is only temporary. Gloves may be worn to avoid this. Prepared bands may be purchased in 250-foot rolls. BORDEAUX MIXTURE__ Bordeaux mixture is the name applied to sprays made by combining dilute solutions of copper sulfate (bluestone) with lime and water. INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS F} Home-made bordeaux mixture should be freshly prepared when used. Ready-prepared mixtures are available on the market. This spray has a blue color and leaves a bluish-white deposit on sprayed surfaces. Its sticking properties are excellent. It is used as a control for the potato leafhopper on potato and as a repellent for flea beetles on various vegetable and flowering plants. Bordeaux mixture is essentially a fungicide and as such is often combined with various insecticides such as nicotine, lead arsenate, calcium arsenate, and others. It is also used as a safener for lead arsenate on apple foliage and as an emulsifier for tank mixtures of lubricating-oil sprays on dor- mant apple, pear, quince, prune, plum, and peach trees. Various formulas for making bordeaux mixture are used. The following is one that is often recommended : For 100 gallons For small quantities Copper sulfate (bluestone) —~---___-_____-_ 8 pounds. 4 ounces. Rresh nya raveds mies — ee e 12 pounds. 6 ounces. UPN a2 raat ee ins tC a RA 2 eC ee aed Re 100 gallons. 3 gallons. On tender plants that would be injured by the above spray it is advisable to use half the quantities of copper sulfate and lime ind1i- cated in the formula. When used as a safener for lead arsenate on apples, it may be reduced in strength to 14 or 34 pound of copper sulfate with 1 or 114 pounds of lime, respectively, per 100 gallons. The use of bordeaux mixture on apple foliage should be avoided in cool, wet weather, since under such conditions it may cause severe russeting of fruit. Powdered copper sulfate is preferable to the crystal or lumpy forms for use in making bordeaux mixture, since it is readily soluble in cold water. When power sprayers are used the required quantity of the powdered copper sulfate is poured, or washed through a screen, into the partly filled sprayer in which the agitator is kept running. After the copper sulfate is completely dissolved, the lime is added either as a dry powder or in the form of a water-mixture. The remainder of the required quantity of water is then added to the tank and the agitation maintained while this is done. When small quantities are needed for usé with compressed-air or knapsack sprayers, the total quantity of water to be used is divided and placed in two pails. The powdered copper sulfate is dissolved in one pail, and the lime mixed with the water in the other. Then the copper sulfate solution and the lime-water mixture are poured together and thoroughly mixed. The mixture is then poured through a strainer into the sprayer. If copper sulfate crystals or lumps are used, they should preferably be dissolved in a quantity of hot water representing one-half the total volume desired. If hot water is not available, place the copper sulfate crystals in a cloth sack and suspend this in the vessel con- taining cold water in such a way that the bottom of the sack is just below the surface of the water. Complete solution should occur i 1 to 2 hours. The suspension of lime in the other half of the water is then added, as the mixture is being agitated, and the whole poured through a strainer into the sprayer. For convenience or where large quantities of bordeaux mixture are needed, stocks of copper sulfate solution and lime suspension may 8 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE be prepared, the former at 1 pound per gallon, the latter at 11% pounds per gallon. These must be stored in tightly covered earthen- ware, wood, or glass containers. Equal quantities (the lime suspen- sion being well mixed before the measured volume is removed) of these preparations can then be diluted, each to one-half the volume desired, and mixed to form bordeaux mixture. One gallon of fin- ished mixture will require 114 cupfuls of each preparation; 3 gallons, 1 quart of each. ; ; Caution.—Bordeaux mixture may cause gastric disturbances if taken internally. All unused portions should be disposed of or covered so that they will be inaccessible to children and animals. It is also somewhat irritative to the eyes and skin. CALCIUM ARSENATE There are several compounds which may correctly be called calcium arsenate. The marketed product, unlike lead arsenate, is not a single chemical compound but a complex mixture of several arsenates and an excess of lime, whose proportions vary considerably between brands and even between different lots of the same brand. However, it usually contains the equivalent of from 40 to 42 percent of arsenic pentoxide. Calcium arsenate absorbs carbon dioxide slowly from the atmosphere during storage and increases its content of water-soluble arsenic oxide, unless it is packed in containers that are practically airtight. This change, however, is relatively unimportant. The domestic manufactured calcium arsenate is a white powder, but when sold as an insecticide it is usually colored pink for the purpose of marking it asa poison. It is used as a spray at the rate of 114 to 3 pounds per 100 gallons of water, in much the same manner as lead arsenate (p. 16), but it is more generally employed as a dust. As a dust it is used principally and in immense quantities in the undiluted form on cotton to control the boll weevil. Likewise in the undiluted form as a dust it is one of the best controls for the tomato fruitworm. Calcium arsenate is sometimes used for the control of cabbage “worms,” the Mexican bean beetle, Colorado potato beetle, pepper weevil, codling moth, apple maggot, grape rootworm, grape berry moth, and cherry fruitfly, and to a limited extent on flowering plants. Applications on peppers and cotton may result in heavy aphid infestations. It is more likely to injure foliage than is lead arsenate, but it is less ob- jectionable from a residue standpoint because of the absence of lead. It is less effective than lead arsenate against the codling moth. Since it is likely to cause foHage injury, three or four times its weight of hydrated lime is often added to render it safer to use. Caution.—Like all arsenical compounds, calcium arsenate is very poisonous to man and higher animals, and should be clearly labeled and stored away from any food products. It should not be applied to the edible parts of fruits and vegetables unless a long period intervenes before harvest or unless acid washes are used to remove the arsenical. CALCIUM CYANIDE Calcium cyanide (Ca(CN),) reacts with moisture in the air and gives off the deadly poisonous hydrocyanic acid gas that is toxic to 4 / INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS g many kinds of insect pests. The gas is colorless, lighter than air, and has an odor resembling that of peach kernels or crushed almonds. A granular product containing about 42 percent of Ca(CN), is used for fumigation, especially in greenhouses, where the material is sprinkled on the walks or soil at dusk after the ventilators have been closed. It is used against greenhouse pests, such as aphids, the Mexican mealy- bug, whiteflies, and the broad mite, at low dosages of 14 to 14 ounce per 1,000 cubic feet of air space, preferably at temperatures of 60° to 75° F. At higher dosages, thrips, scale insects, mealybugs in gen- eral, and various bulb pests are also destroyed. Plants vary consid- erably in their tolerance to the gas, and the margin of safety between a fatal dose for an insect and a plant is very narrow, therefore it must be used with care. Calcium cyanide is used as a fumigant for the control of thrips and mealybugs on gladiolus corms, at the rate of 5 ounces per 1,000 cubic feet of space with an exposure of 2 hours. The corms should be warmed to at least 60° F. just prior to the fumigation and held at that temperature during the fumigation. Colonies of ants in the ground may be controlled by dusting powdered calcium cyanide into their nests or pouring a teaspoonful into each of several holes about an inch in diameter, made with any convenient instrument, about 6 inches deep and spaced 1 foot apart. Openings of the holes should be closed, but treated areas should not be covered with papers, since the poisonous hydrocyanic acid -gas may injure the grass or other vegetation. Caution.—Hydrocyanic acid gas, from whatever source derived, is very poisonous to all animals and plants. (See also Sodium Cyanide, page 33.) The dust should be kept in tight containers, labeled plainly, and stored in a dry, safe place. This fumigant should be used only by those thoroughly familiar with its poison- ous nature to humans and with the tolerance of different plants to the gas. CARBON DISULFIDE Carbon disulfide (CS,) is a heavy, colorless or faintly yellow liquid which boils at 115° F. It has a disagreeable odor and is very volatile. The vapors are poisonous and very inflammable, and are explosive when mixed with air in certain proportions. They will sometimes become ignited from contact with hot steam pipes. Carbon disulfide is used as a soil fumigant or as an emulsion against grubs of the Japanese beetle, white grubs, wireworms, and colonies of ants in the ground. To control ants in lawns, make holes about 3 inches deep in the soil with an 4ron bar or sharpened stick, spacing the holes about 1 foot apart throughout the entire infested area. Into each hole pour 1 teaspoonful of carbon disulfide, then close the opening by pressing the earth in place with the heel. Where the ant nests occur in ground between stones of a walk, apply 1 or 2 tablespoonfuls in each hole. Carbon disulfide cannot be used safely near growing plants. Ant nests in trees may be destroyed by injecting carbon disulfide into openings to the galleries with an oil can and then plugging the open- ings with moist clay. 10 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE An emulsion of carbon disulfide is used for the control of white grubs, including larvae of the Japanese beetle, in the lawn and flower border. The emulsion contains— Resin: fish-oil ‘soaps 22222 a aS ee ee 1 tablespoonful. Water 22 <2" 58 22 kee eee ee ee 3 tablespoonfuls. Carbon disulfide: === _ 22225 22 ee ee Otablespoomtuls: Place the soap and water in a quart bottle and shake until the solu- tion is uniform. Then add the carbon disulfide and shake for 1 or 2 minutes or until a creamy emulsion has formed. To treat the soil, stir 4 teaspoonfuls of this emulsion into a gallon of water, or the entire quantity into 11 gallons of water, and apply with a sprinkling can at the rate of 3 pints per square foot. Carefully measure the area to be treated and apply the emulsion uniformly without excess in any part, otherwise injury to grass roots or other plants will result. If the lawn is kept moist for several days prior to the application of the insecticide, the grubs will tend to feed near the surface, where they can be reached by the emulsion. Caution.—Because of its inflammability and poisonous nature, the greatest caution should be used in handling carbon disulfide. It should be kept in tightly closed containers, in a cool place, and away from fire, lighted cigarettes, and hot pipes. Because of the fire hazard, this chemical cannot be shipped by mail or express. Inhaling the gas causes dizziness and nausea, and the inhalation of large amounts is deadly. Some bureaus of the Department have discontinued the use of carbon disulfide for any purpose, and have issued regulations to that effect. The foregoing description. of the chemical and the formula for compounding it with other substances must not be interpreted by the employees of those bureaus as justification for its use. These are included as a mat- ter of general information to the public. Carbon disulfide is manufactured in this country and is obtainable in small quantities in bottles or cans and in large quantities in steel drums. CHLOROPICRIN Chloropicrin (CCl,NO,) is a heavy, colorless, pungen, noninflam- mable liquid manufactured in the United States. It is obtained by subjecting picric acid to the action of chlorine. This compound was used in the first world war as a lethal, tear, and vomiting gas. It has also been used for killing rats in ships. Chloropicrin is used as a soil disinfectant for various disease or- ganisms and nematodes in greenhouges and potting soil, and in small field areas where valuable crops are to be grown. When so used it also acts against other soil insect pests, including white grubs and garden symphylids. It destroys all plant growth in the immediate area. It is intro- duced into the soil by means of a special applicator. It is applied at different concentrations according to the pests in- volved. Full directions for the use of this fumigant are usually fur- nished by the manufacturer. The operator should wear a gas mask as a protection against the irritating fumes. INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS ll1 Chloropicrin may be purchased in 1-pound glass bottles or in cylin- ders of from 1 to 100 pounds capacity. CRYOLITE Cryolite, or sodium fluoaluminate (Na,AIF,), is a white crystalline chemical which is used as a substitute for arsenicals. Both natural cryolite imported from Greenland and synthetic materials of similar composition are available, and for most uses there is little difference between them. It will not damage beans when used for Mexican bean beetle control, or flowering plants when used to control blister beetles, Fuller’s rose beetle, and the black vine weevil. It is frequently used on apple trees for the control of the apple fiea weevil and the codling moth, but in the East and Middle West it sometimes causes injury to fruit and foliage. It cannot be used with safety on corn. When used as a spray, the usual dilution ranges from 6 to 10 pounds to 100 gallons of water. Cryolite and other fluorine compounds sometimes cause injury when applied to plants previously treated with soaps or with sprays con- taining arsenicals. For the preparation of cryolite dusts, talc, clay, and sulfur may be used, but not lime. Cryolite mixture is prepared at the rate of 40 to 60 pounds of the chemical to 60 to 40 pounds of the carrier. Caution.—Cryolite is a poison, and should be handled with care. This is one of the fluorine compounds, and apples and pears con- taining residues in excess of 0.02 grain of fluorine per pound will be subject to seizure and destruction by health officials. CUBE See Rotenone-containing Roots (pp. 30-32). DERRIS See Rotenone-containing Roots (pp. 30-32). DILUENTS OR CARRIERS The ideal diluent for an insecticide in the powder form is one which is a suitable carrier for it and which functions satisfactorily in dusting machinery. The diluent, to be a suitable carrier, must be such that when mixed with the insecticide the two will remain as a homogeneous mixture both before and after discharge from the duster, or until the dust is deposited on the plant. It should also be compatible from the chemical standpoint, that is, it should not cause an undesirable chem- ical change in the insecticide with which it is mixed. The more com- monly used materials listed below are all domestic products. Bentonite.—See page 6. China clay—This material is also known as kaolin. It is a white, residual clay, and as marketed it is not a definite chemical compound but rather any one of several hydrated aluminum silicates. Diatomaceous earth and kieselqguhr.—These materials may be white, light gray, or pale buff. They are the siliceous remains of fossil diatoms. 12 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE Gypsum (landplaster)—Chemically this is calcium sulfate | (CaSO,.2H,O), a white or yellowish-white powder. It is used with — calcium arsenate in the control of cucumber beetles. ¢ Hydrated lime—See page 14. Chemically this is calcium hy- © droxide (Ca(OH).) and is commonly used with arsenicals and asa ~ carrier In nicotine dusts. | Pyrophyllite—Chemically this is anhydrous aluminum silicate (HA (SiO;).), white, and is very similar to tale in physical prop- erties. It has recently come into general use as a diluent for cube and derris. Sulfur.—see page 35. Talc—In the solid form this material is known as soapstone. Chemically it is a magnesium silicate (H.Mg,(Si0;)4). As marketed as an insecticidal diluent it is usually a white or grayish-white powder composd of microscopic platelike particles that give it a smooth feel. It is used in derris and cube dust mixtures. Tobacco dust.—See page 37, Walnut-shell flour.—This is a brown powder obtained by finely grinding the shells of Persian (“English”) walnuts. It is used in the preparation of impregnated dusts. It is not so suitable as tale as a diluent for rotenone-containing roots (derris and cube). Wheat flour.—This is the ordinary “white” wheat flour familiar to all. DINITRO COMPOUNDS These are organic compounds manufactured in this country which have come into general use in certain fruit-growing districts for the control of scale insects, the fruit tree leafroller, the pear psylla, the bud moth, mites, and aphids. . They are of two types, (1) those that are sold in powder form to be added by the grower to lubricating-oil sprays, and (2) those sold in liquid form to be added to water. The former group includes dinitro-o-cyclohexylphenol and dinitro-o-cresol. The principal com- pound in the second group is sodium dinitro-o-cresylate. Dinitro- o-cyclohexylphenol is also used on citrus as a contact insecticide in the form of a diluted dust to kill the citrus red mite, and it may be used on potato and bean to control the potato leafhopper. These materials should be used according to the manufacturers’ - recommendations, since they may contain diluents in varying amounts. The oil-soluble powdered forms, when added to dormant spray oils, generally reduce the quantity of oil required. Dinitro insecticides as now used should be applied to deciduous trees only while the buds are dormant. When property used, these compounds present no special hazard to human health. ESSENTIAL OILS Essential oils are volatile, aromatic materials obtained from plants, usually by steam distillation, and have odors generally characteristic of the plant source. They are employed as attractants in insect traps. ‘The essential oils by themselves are relatively nontoxic. INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 13 Geraniol and eugenol are used in Japanese beetle traps; oil of sas- safras (natural), bromostyrol, oil of anise, and geraniol in sugar solutions are used to trap codling moths. Terpeny] acetate and ethyl cinnamate in sugar solutions have proved very attractive to the oriental fruit moth. Amyl salicylate is used as an attractant for tobacco hornworm moths. Preservatives such as sodium benzoate, and poisons such as tartar emetic, sodium arsenite, and nicotine sulfate may be added to the sugar-aromatic combinations. ETHYLENE DICHLORIDE Ethylene dichloride (CH.ClI-CH:Cl), which is manufactured in this country, is a colorless liquid having a sweetish odor similar to that of chloroform. The vapor is heavier than air and penetrates the soil readily. The chemical burns with difficulty when ignited. It is used in the form of an emulsion for control of the peach-tree borer, the amount required depending upon the age and size of the tree. Prepared emulsions of ethylene dichloride are available on the market, or they may be made up as follows: Stir 9 parts by volume of ethylene dichloride into 1 part of a potash fish-oil soap containing about 30 percent of actual soap. Dilute and use as recommended by the county agricultural agent, State agricultural college, State entomologist, or the United States Department of Agriculture. A mixture of 3 parts of ethylene dichloride and 1 part of carbon tetrachloride is used as a fumigant to control the gladiolus thrips on the dormant corms while in storage. Caution.—When the vapor of ethylene dichloride is inhaled it has an anaesthetic action, although less rapid than that of chloroform. Unless it is breathed in high concentrations over a long period of time, no harmful results need be feared. FISH OIL Various domestic fish oils having iodine numbers of 120 to 145 are sometimes used as adhesives for lead arsenate in the control of the codling moth and gypsy moth. Usually 1 pint-of the oil and 3 pounds of lead arsenate are used per 100 gallons. The inclusion of 1 part of oleic acid in 19 parts of the fish oil generally improves the type of lead arsenate deposit obtained. Fruit sprayed with lead arsenate and fish oil can be cleaned more easily with alkaline than with acid washes. HELLEBORE Hellebore, the ground root of the plant false hellebore (Veratrum album in Europe or V. viride in the southeastern part of the United States), is no longer much used, but formerly it was known to gardeners as a remedy for the control of sawflies on currant and gooseberry. For use as a spray, add 1 or 2 ounces of this material to a gallon of water. When used as a dust, 1 ounce of hellebore is diluted with 5 or 10 ounces of flour, tale, or lime. It has been used also as a larvicide for houseflies in manure. 14 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE It is not very poisonous to man but may cause discomfort if in- haled. It should be stored in tightly closed receptacles to prevent the loss of its toxic properties. The commercial product comes chiefly from the European species. i HOT-WATER TREATMENT Immersion of plants, corms, or bulbs in heated water, maintained at a constant temperature ranging from 110° to as high as 120° F, for the period of treatment, is a method used in the elimination of a number of pests, including the gladiolus thrips, aphids, and mealy- bugs on gladiolus corms, the larvae of bulb flies and mites in narcissus and other bulbs, and the cyclamen mite in crowns and distorted growths of some ornamental plants. The treatments for these pests vary, and publications dealing with each should be consulted for specific recommendations. Small quan- tities of bulbs or plants can be treated in a laundry tub or similar container, provided that an accurate thermometer is available for checking the temperature. In carrying out the treatment, fill the vessel three-fourths or more full of water, using sufficient hot water to bring the temperature up to the desired point. Submerge the plants or bulbs in screen boxes or loose net bags and add hot water to maintain the desired water temperature, as it is lowered by the cooling effect of material being treated or by radiation. After the bulbs or plants have been warmed to the desired temperature in the bath, less additional hot water will be required to maintain the tem- perature. If the treatment can be carried out’ in a warm room and the tank kept covered, the temperature will be more easily main- tained. During the entire treating process the water should be stirred with a paddle frequently enough to maintain a uniform temperature throughout the container. Free circulation of the water should not be blocked by the treatment of too many plants or bulbs at one time. The duration of treatment is calculated from the time the tempera- ture is brought up to the desired point after the plant material has been placed in the water. The treatments required to control some common pests are: The cyclamen mite and broad mite, 15 minutes at 110° F., except 20 minutes for large clumps of delphinium or gerbera and for trays of loosely placed straw- berry plants. Bulb mites on tuberoses, narcissus, and other bulbs, 1 hour at 110° F. Bulb flies in nareissus and amaryllis, 144 hours at 111° F. The grape mealybug on gladiolus corms, 30 minutes at 116° F. The gladiolus thrips on gladiolus corms, 30 minutes at 112° F. The boxwood leaf miner on boxwood, 5 minutes at 120° EF. during late fall and early spring. HYDRATED LIME Hydrated lime (calcium hydroxide, Ca(OH).),. is a finely divided, white powder which can be distributed satisfactorily by dusting ma- chines. Since this domestic product is low priced and readily avail- able, it is used as a filler or diluent in many insecticidal and fungicidal dust mixtures, particularly those containing monohydrated copper sul- fate, sulfur, or arsenicals. It is used in making nicotine dusts. Also, it acts as a safener in calcium arsenate-water sprays. In recent years INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 15 it has supplanted unslaked lime or quicklime, in the preparation of bordeaux mixture. It is commonly used by growers as a repellent to insects on melons, cucumbers, and other vegetables, and to repel the Japanese beetle on certain fruit crops, although, owing to its caustic nature, it may retard development of some plants. It is recommended for the control of the garden slug. For the preparation of bordeaux mixture the hydrated lime should be freshly made. Hydrated lime is commonly used with zinc sulfate on peaches and with either zine sulfate or copper sulfate on apples, as a safener for lead arsenate. Caution.—The dust, when inhaled, is somewhat irritating to the respiratory passages. Keep containers well closed. This material is usually available locally, in hardware stores or from dealers in building supplies. KEROSENE EMULSION Kerosene emulsion is an effective contact insecticide. It was in rather general use until replaced by the white-oil emulsions, which are safer to use on a wide variety of plants. If not properly prepared, kerosene emulsion may cause injury to succulent plants such as coleus, ferns, heliotrope, begonia, and crucifers, although it can be safely used on chrysanthemums, crotons, palms, and rubber plants. Other, hardier plants are not injured by even a 10-percent emulsion. Diluted to 5 percent, this emulsion is effective against mealybugs, rose midge larvae in the soil, immature scales, and red spiders, while a 1- percent emulsion can be used successfully against aphids, thrips, and ants in the soil. Kerosene emulsion should be applied preferably late in the afternoon and the plants thoroughly syringed with water the next morning before sun-up. Soil overrun with ants may be freed of these pests without injury to the plants by drenching the infested areas with a 1-percent emulsion. A se emulsion of kerosene is prepared according to the following formula: For large For smail ; quantities quantities SSE ee Ree Cod ee EE ee 2 gallons. 1 pint. Fish-0il soap or laundry soap___________ 14 pound. 14 ounce. EET 2) eae or on ie oe ee bE eallion. 14, pint. If hard bar soap is used, first cut the soap into chips and then dissolve it in hot water, and while it is still hot add the kerosene very slowly, stirring constantly. The mixture should be pumped through a bucket pump back into the container for several minutes, or until a creamy emulsion has formed. Small quantities may be made with an ego beater. The stock emulsion may be kept until needed in a tightly stoppered bottle or fruit jar. However, it will deteriorate with age and the kerosene will collect at the top of the mixture. This is the case with some of the commercial emulsions which have been prepared for some time. This free oil is the cause of much injury when applied to plants. The emulsion may be reclaimed by reheating and agitating, with or without the addition of-soap. 535593 ° -_43——2 16 MiSC. PUB. 526, U. S. DEPT. OF AGRICULTURE To dilute the stock emulsion to the desired strength for spraying, the following quantities should be used: Strength of Emulsion to make Emutsion to make spray desired 1gailon of spray 100 gallons of spray 1 percent t2= =e Rae ae eee 4 tablespoonfuls. 6 quarts. 2° percent. <2. ee eee 8 tablespoonfuls. 38 gallons, 5 percenta2e i 2 sae 7 eek ee eee 14% cupfuls. 71% gallons. 10 “percent == 22> =. ase ee 21% cupfuls. 15 gallons. Kerosene alone at the rate of 1 or 2 quarts per 100 gallons is some-— times used with lead arsenate for control of the codling moth. For this purpose it may be emulsified in the tank with bordeaux mixture, with some of the proprietary spreaders, or with the milder soaps. He used in this manner it acts primarily as an adhesive or deposit uilder. LEAD ARSENATE (ACID) There are several chemically different compounds known as lead arsenate. Two of these are commonly used as insecticides. The one - usually sold is “acid lead arsenate” (di-lead ortho arsenate, PobHAsO,). The other, generally called “basic lead arsenate,” is discussed on page 17. Lead arsenate is a fine powder and is readily kept in suspension in a spray. The residue tends to adhere strongly to foliage. Acid lead arsenate should contain the equivalent of not less than 31 percent of arsenic pentoxide (As,O;). It should not contain more water-soluble arsenic than the equivalent of 0.5 percent of arsenic pentoxide. . Lead arsenate is manufactured in this country as a white powder, but since 1938 it and other white arsenicals have been colored pink when marketed as insecticides. This material is not quite so toxic to insects as is paris green but is much safer to apply on plant foliage. It is used both as a spray and as a dust, with a suitable carrier. its most popular use is for control of the codling moth, plum curcuho, apple maggot, pear slug, grape berry moth, and many other chewing insects attacking fruits. It is also used for many insects on flowers, trees, and shrubs, such as bagworms, beetles, weevils, and grasshop- pers, and for the control of the Colorado potato beetle, beet webworm, and tomato hornworm. It also finds extensive use in treating soil to control Japanese beetle and Asiatic garden beetle larvae and related soil-infesting forms. Lead arsenate is ordinarily used at dosages ranging from 2 pounds to 8 pounds per 100 gallons of spray. It may be used with other insec- ticides, such as nicotine and oil emulsion, or with fungicides like lime- sulfur, sulfur, and bordeaux mixture. It should not be used with sodium sulfide or potassium sulfide, or with most soap sprays. It should not be used on any vegetable crop where the portion treated is to be subsequently used for food, nor on fruits after the fruit has formed, except in instances where the interval before harvest is sufh- ciently long to permit the poison to be weathered off or where the resi- dues will be removed at harvest by acid or alkaline washes. In some localities materials such as a weak bordeaux mixture or zinc sulfate and lime must be added to lead arsenate sprays to avoid injury to foliage. On beans this insecticide often causes plant injury and reduction in yield. ey INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 17 Caution.—Lead arsenate is a very poisonous compound and should be stored in plainly labeled containers away from all food products. Both lead and arsenic residues on treated plants are poisonous. The Federal tolerance for lead on apples and pears is now 0.05 grain per pound and for arsenic it is 0.025 grain of As,O; per pound. LEAD ARSENATE (BASIC) Chemically, basic lead arsenate is lead hydroxy arsenate (Pb,(PbOH) (AsO.);). It should contain about 23 percent of total arsenic pentoxide (As.O;) and less water-soluble arsenic than the equivalent of 0.5 percent of arsenic pentoxide. Like the much more commonly used acid lead arsenate, this ma- terial is a white powder which is colored pink when marketed as an insecticide to denote that it is a poison. Its use is virtually limited to particular areas on the Pacific coast and in eastern peach orchards, for certain chewing insects, where acid lead arsenate causes plant injury. It is less effective in controlling insects than is the acid form. Normally it is used at a rate of about 4 to 6 pounds to 100 gallons of water. Caution.—Like acid lead arsenate, this material is toxic to man and higher animals, and should be stored in a safe place in clearly labeled packages. The spray-residue tolerances for acid lead arsenate, as given above, apply also to basic lead arsenate. LIQUID LIME-SULFUR AND DRY LIME-SULFUR As the name implies, lime-sulfur is made from lime and sulfur. A complex mixture containing principally calcium polysulfides, it may be purchased in concentrated solution or as a dry powder, or it may be made on the farm. It is marketed in concentrated form as a deep amber-colored liquid, or as a yellow-orange powder. It is applied in the dilute form and is ill-smelling and irritating to the user. Liquid lime-sulfur is used chiefly as a scalicide and a fungicide on fruit trees and woody shrubs. It is used extensively for the contro] of the potato psylla in the Western States and is also valuable for the control of the peach twig borer, pear psylla, and blister mite. As a scalicide it has been displaced in some localities by lubricating- oil sprays. When used in the dormant season to control scale insects it is applied at a strength of 10 to 14 gallons of the liquid concentrate in 100 gallons of spray. As a fungicide and as a spray for the com- mon red spider and some other mites on plant foliage it is usually diluted to a strength of 2 gallons in 100 gallons of spray. For control of the cyclamen mite on chrysanthemums and snap- dragons, a lime-sulfur spray consisting of 1 to 2 quarts to 100 gallons of water with the addition of 34 pint (11% cupfuls) of a spreader sodium oleyl sulfate containing a synthetic resinous sticker—has proved effective. This spray has the advantage of not staining the foliage as does lime-sulfur solution without the spreader. For some purposes dry lime-sulfur may be substituted for liquid lime-sulfur at the rate of 4 pounds for 1 gallon of the liquid. On 18 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE _ deciduous foliage do not follow a sulfur spray with sprays contain- ing oil until all sulfur residues have disappeared. Directions for the preparation of self-boiled lime and sulfur and home-boiled lime-sulfur concentrate may be obtained from the county agricultural agent, the State experiment station or State entomologist, or the United States Department of Agriculture. Caution.—Lime-sulfur sprays are very caustic to the skin, espe- cially at the strengths used in the dormant season. Persons ex- posed to this material should protect their faces by covering them with grease or vaseline before they begin spraying, and should avoid getting any of the material into the eyes, where it will cause acute temporary discomfort. Don’t allow lime-sulfur spray to drift onto painted buildings, or a very unsightly stain may result. MAGNESIUM ARSENATE Several compounds of magnesium oxide and arsenic oxide are known, and it has been reported that the commercial product sold as “magnesium arsenate” contains the dimagnesium salt, MgHAsO,, and two basic salts, principally one having the composition Mg;(AsO,)..MgO.H.O. There is also present a large excess of magne- sium oxide or hydroxide, which is necessary to keep down the content of water-soluble arsenic. Magnesium arsenate is a white powder but is colored pink when packaged as an insecticide to indicate its poisonous nature. It is used as a spray, at the rate of 4 pounds in 100 gallons of water, against the Mexican bean beetle. Derris and cube have largely replaced it for the control of this insect, but it can be used where these are not available, provided application is discontinued when the bean pods start form- ing. Magnesium arsenate is not used for the control of other insects. Its tendency to injure foliage 1s one drawback to its extensive use. Caution.—Magnesium arsenate, like all arsenicals, is a poison- ous compound and should always be so labeled, and stored away from ali food products and out of the reach of children. For spray-residue tolerance, see page 3. MERCURIC CHLORIDE Mercuric chloride (HgCl,) is known also as corrosive sublimate and as bichloride of mercury. It is soluble in water, although it dissolves in cold water very slowly. Commercially it is available as a white powder, as crystals, or in the form of 7.5-grain tablets. The powder form is used commonly for insecticidal purposes. A solution of 1 ounce in 71% gallons of water or 1 level teaspoonful in 10 quarts of water, or two 7.5-grain tablets to 1 quart of water (1: 1,000) is prepared by dissolving the compound in a small quantity of hot water and diluting it with cold water. This solution is used in the control of fungus gnats, earthworms in greenhouses, and the cab- bage root maggot. To avoid injury to the plant, keep the solution off of the fohage. Mercuric chloride is also used for the treatment of dormant gladiolus corms to control the gladiolus thrips. Other common uses are as a fungicide and a germicide. INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 1Y Caution.—Mercuric chloride is a violent poison and must be stored in plainly labeled containers which are marked “Poison.” It reacts with metals; and solutions should, therefore, be placed in wooden, earthenware, or glass containers. It is advisable to wear rubber gloves when working with this compound. MERCUROUS CHLORIDE Mercurous chloride (HgCl) is known also as calomel. It is a white powder insoluble in water. Suspensions or mixtures of calomel in water are employed for the control of the cabbage maggot and the onion maggot, 3 or 4 ounces being used in 10 gallons of water. One ounce of gum arabic is gener- ally added to 10 gallons of the mixture to keep the calomel from settling rapidly. The use of this material for the control of these maggots is preferable in some cases to the use of corrosive sublimate because of the highly toxic nature of the latter to man and animals. Caution.—Mercurous chloride is not generally regarded as dan- gerously poisonous, being commonly used, in small doses, as a purgative. However, it should be stored in labeled containers out of the reach of children and irresponsible persons, since excessive doses are poisonous. METALDEHYDE (SLUG BAIT) Chemically, metaldehyde is a polymer of acetaldehyde, namely (C.H,O)n, and only recently has been manufactured in this country. It is available as a white powder which is insoluble in water but soluble in benzene and chloroform. - The technical grade is available in tablet form. Metaldehyde is very attractive to slugs and snails and is used in the bait form for these pests. It is prepared as follows: Metaldehyde_____- A 3) Nie 8s Pe cee Ee lee — 1 ounce. Bran-or, bread erumbs=——- + .- _— ere Eres eet ee __ 314 pounds. To prepare the bait, mix the metaldehyde and the bran or bread crumbs and store the bait in a jar or other container until needed. When ready fo use the material, place a portion of it in a pan and add water slowly, while stirring it, until the bait is moistened, yet remains crumbly when a handful is squeezed together. At dusk this moistened bait is scattered over the-beds that are infested with slugs, as described for applying poisoned-bran mash (p. 28). The treatment may be repeated in 2 or 3 weeks if the snails reappear, or if their injury and slimy trails are discovered. After having eaten baits containing metaldehyde, the slugs are stupefied and finally die. Where the vegetation is dense and humidity is high, the affected snails are killed more slowly or they may recover. Under such conditions the following bait containing calcium arsenate is more effective and kills more rapidly than baits containing only metaldehyde: For small quantities For large quantities Galeigm:.arsenates 2.2 es 8 _ 1 ounce. 1 pound. J RST TEE 2) 7, | 2s eal a ee a aa ae oe 1s ounce. Ly pound. jE oT aba pal SER are See eee eee 1 pound. 16 pounds. 1 OY 1S SES a al ac al i ate Solas 2 teaspoonfuls. 1 pint. Water=--= re eae 1 pint. 2 gallons. 26 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE In situations where no domestic or farm animals have access to the bait, apply it in piles of about a tablespoonful each, spaced about 2 feet apart; otherwise it should be scattered in the infested area as recom- mended for applying poisoned-bran bait (p. 28). Unless washed away by watering or rains it remains effective for some time, and baiting two or three times during the year gives adequate control. Ready-mixed baits containing calcium arsenate and metaldehyde are available on the market. | Caution.—Since metaldehyde may cause poisoning when taken internally, the containers should be plainly labeled “Poison” and kept out of reach of children and others. METHYL BROMIDE Methyl bromide (CH,Br) at temperatures above 40° F. is a gas that is heavier than air. Under pressure it becomes a heavy, colorless hquid which is only slightly soluble in water. It is soluble in alcohol, chloro- form, ether, and carbon disulfide. Commercially it has some use as a fire extinguisher and as a refrigerant. The gas is noninflammable, almost odorless, very penetrating, and is poisonous. As commercially produced it has a purity of 9914 percent or better. For the destruction of insects and mites on plants and in soil methyl bromide is being used as a fumigant in specially constructed chambers. Under carefully controlled conditions of temperature, exposure, and dosage it will destroy these pests without injury to the plants. In this respect it is more useful as a general treatment than other fumi- gants. Special fumigation chambers and special instructions are necessary for its proper use. Information on these points can be furnished, to - those who have need for it, by the Bureau of Entomology and Plant pees United States Department of Agriculture, Washington, Caution.—When working with methyl bromide it is necessary to use a gas mask provided with a canister that will absorb the gas. It is toxic, and should not be allowed to come into contact with the skin. Containers of this gas should be stored in a cool, well-ventilated place outside of inhabited buildings. The gas is practically odorless, but dangerous concentrations of it may be readily detected by the use of a specially devised halide leak de- tector or lamp. Methyl bromide is obtainable in small 1-pound cans or in cylinders containing 10, 50, or 150 pounds net. : MINERAL OIL Mineral oil, or petroleum oil, is obtained by refining native crude oil. Refined petroleum oils used for controlling insects may be di- vided into two general types known as dormant oils and summer oils, the latter being highly refined products, also called white oils. Dormant oils—Dormant oils having a viscosity of from 90 to 150 seconds (Saybolt, at 100° F.) and an unsulfonatable residue of from 50 to 70 percent are emulsified at the rate of 2 to 6 gallons per 100 gallons of water for the control of several fruit insects, such as the INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 2] San Jose scale, pear psylla, thistle aphid on prunes, fruit tree leaf roller, aphids, and spider mites. The oil is sometimes used in combination with dinitro compounds to facilitate control of certain pests, in which case less oil is used. Dormant oils meeting the above specifications may be purchased from most oil companies and then emulsified. For this purpose bor- deaux mixture, calcium caseinate, blood albumin, soybean flour, casein- ammonia, bentonite. or other emulsifiers may be used. Consult your State agricultural college, or county agricultural agent for directions. Dormant oils are also sold in a self-emulsifiable form ready for dilu- tion with water. White oils—White or summer oils are used in the control of the codling moth, spider mites, and leafhoppers on apples, scale insects, mealybugs, and the red spider and other mites on various ornamental and: flowering plants, and the corn earworm on corn. Though some- times used alone, they generally are combined with sprays containing lead arsenate, pyrethrum, derris, cube, or nicotine. For most purposes the light oils of approximately 52 seconds vis- cosity (Saybolt, 100° F.) are preferred, but lght- medium (about 63 seconds viscosity) and medium (about 72 seconds viscosity) are also employed. These oils should have not less than 85 percent of unsul- fonatable residue, and for use on tender plants they are usually diluted so that the final spray contains from 14 to 1 percent of oil. On shrubs and evergreens a 2-percent spray may be employed. White oil sprays act as adhesives, and when combined with arseni- cals they interfere with the removal of the poisonous residues. They may also cause injury to foliage and affect the coloration of apples if applied in too large quantities or too frequently. O7/ sprays should not be applied to foliage on which residues from sulfur sprays are present, because severe burning may result. Summer oils may be emulsified with the same materials used to emulsify dormant oils, or with nicotine bentonite. They are, how- ever, most commonly sold as miscible or so-called “emulsible” oils con- taining about 97 percent of oil, or paste-type emulsions containing 70 to 85 percent of oil. These contain emulsifying agents and need only be diluted with water. The manufacturers usually give full in- structions on the containers for use against various pests. The formulas given below have been found effective for use on ornamental plants. For red spiders: Derris or cube powder (4 percent of rotenone)_______ 1 tablespoonful. White oil emulsion (83 percent of oil) __~-__-_-_-____ 4 teaspoonfuls. WY eo ee Se se Tk 2 aia Ree _.. 1 gallon. For mealybugs and scale insects : Nicotine sulfate solution (40 percent of nicotine)____ 1% teaspoonfuls. White oil emulsion_____________- 3 tablespoonfuls. Waters? ie ta: : -. 1 gallon. For newly hatched Beale insects on hardy shrubs and also against lacebugs : White oil emulsion (83 percent of oil) _- 1 eupful (or %& pint). Soap flakes______- £ Bees cee ed oe , eaptuls. Nicotine sulfate solution_____- ap ere = 3 _.. 4 teaspoonfuls. SON RE ee a eer ea: et = 8. ae Bellona. Ze, MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE Another spray that may be used against lacebugs on such shrubs as azalea or rhododendron is: Derris or cube powder (4 percent of rotenone) _____. 5 tablespoonfuls. White oil emulsion (83 percent of oil) ______-_____-___ % cup. Winter ticle ae ole = ee SSeS Se eallons: Some ornamental plants, including sweet peas, ferns, and orchids, are injured by oilsprays. Other plants may be injured where the spray collects in cavities or leaf axils; as the water evaporates, excess oil is left at these points. Palms and other plants having cavities in which spray material collects should be syringed with water or laid on their side after being sprayed with oils. Certain pyramidal junipers and spruces may also be injured by oil sprays. It is advisable to wash or syringe the more tender plants with water an hour or so after apply- ing the spray. Although oil emulsion can be prepared at home, it is much more satisfactory for the user of small quantities to purchase the prepared roduct. i Along with extract of pyrethrum, a white mineral oil or summer oil of 100 to 150 seconds viscosity (Saybolt, at 100° F.) is used to pro- tect sweet corn from injury by the corn earworm. The pyrethrum extract (sometimes called oleoresin of pyrethrum) having a 20- percent pyrethrin content is available on the market. To obtain a 0.2-percent pyrethrin content, which is recommended, 38 ml. (or about 114 fluid ounces) of this extract should be added per gallon of oil. Application of about 14 teaspoonful to each ear is made with a modi- fied force oiler (oil can) or with a medicine dropper, one-half or three-fourths full, according to the size of the ear. Treatment is made immediately after the ears are fertilized, that is, as soon as the silks become wilted but not before about the third day after silk becomes exposed. NAPHTHALENE Naphthalene (C,,Hs), obtained from coal tar, is generally sold as white crystalline flakes or as the well-known “moth balls.” Crude naphthalene is sold in flake and chip form and is colored by the im- purities present. Naphthalene vaporizes at a noticeable rate at room temperature, but the vapor, although detectable by its tarry odor, is not sufficiently concentrated to produce inflammable mixtures with air. The use of the refined product in clothes moth control is well known. A less refined material has been used as a soil treatment for wireworm control in irrigated lands of the West and for the control of the carrot rust fly. Consult the State entomologist for information on its use locally for these pests. Naphthalene in the form of flakes or in solution in certain solvents is also volatilized in greenhouses over lamps for the control of red spiders and thrips on carnations and certain other crops that will tolerate the fumes. The fumigations are carried out on cloudy days or at night at a temperature near 80° F. and with high humidity. From 2 to 3 ounces are used per 1,000 cubic feet of space, and the lamps are adjusted to volatilize the flakes evenly over a period of about 6 hours. The margin of safety between a dosage tolerated by plants and one toxic to insects 1s very narrow, therefore it should not be used in greenhouses except by experienced workers. INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 25 The flakes are mixed with soil to destroy wireworms, white grubs, garden centipedes, and other pests at the rate of 500 pounds per acre or 19 ounces distributed under 100 linear feet of 12-inch furrow slice. They are also scattered in places frequented by sowbugs, millipedes, and slugs. When mixed with dormant gladiolus corms in storage at the rate of 1 handful per 100 corms or 1 pound per 2,000 corms, it destroys the gladiolus thrips. It should be used only in the fall, after harvest. Late spring treatments may injure the corms. Caution.—Persons breathing naphthalene vapors for several hours will experience irritation of the respiratory tracts and eyes. High concentrations can cause the same discomfort in a very short time. NICOTINE Nicotine (N,,H,.N.) is an alkaloid which occurs in tobacco and related plants. In its pure state it is an oily, colorless liquid which is soluble in water. alcohol, and fatty oils. For spraying purposes it is commonly sold in the form of solutions of nicotine sulfate. The stand- ard brands on the market usually contain the equivalent of 40 percent of nicotine. They are deep-brown, thick liquids and are very stable. Nicotine sulfate is a byproduct of the tobacco industry in the United States and normally is readily available. Nicotine is used as a contact insecticide, a stomach poison, or a fumigant. As a contact spray nicotine sulfate (40 percent nicotine) is used at the rate of 1 to 2 pints per 100 gallons of water or other sprays, to which may be added 2 to 4 pounds of soap. Nicotine sulfate is compatible with bordeaux mixture, lime-sulfur, or other alkaline materials. These spray combinations are effective against aphids, some species of leafhoppers, adult whiteflies, the iris thrips, rose slugs, certain leaf miners, the young stages of plant bugs, mealybugs. and scale insects. The combination of nicotine sulfate and mineral oil is effective as a stomach poison, contact spray, and ovicide and is used against the codliing moth. A more effective codling moth spray is the combina- tion of nicotine sulfate and bentonite. See Nicotine Bentonite (p. 24). A spray used for control of the boxwood leaf miner during the adult emergence period is made up as follows: For small For large quantities quantities SC PSP STS Es | ah See een ies Snaete a 1 teaspoonful. 114 pints. UU ELIS © Bailey at ee Sela ers Nee ees 1 pint. 12 gallons. Lice tS, ogee 42s 1 ee TD) pound. 8 pounds. AN SAG) INE ao aS ES age A a fee 8 _ to moisten. to moisten. Apply at the rate of 20 pounds per acre. Caution.—These baits are poisonous and must be stored in la- beled containers so that they will not be used for human or animal consumption. Bran is usually available locally at feed stores or mills. Some feed, stores sell prepared poisoned baits. PYRETHRUM, OR INSECT POWDER? One of our oldest insecticides and one of the most generally useful is pyrethrum. Pyrethrum powder is a plant product “and is obtained by grinding the flower buds of the plant Pyrethrwm cinerariaefolium, a plant which belongs to the same botanical family as chrysanthe- mums. The source was originally Persia and Dalmatia, and more recently Japan, but now Kenya Colony, Africa, supplies pyrethrum to this country and our allies. The toxic ingredients of the flowers are the pyrethrins I and II, which together occur in Kenya flowers to an average of about 13. percent. “In the country of origin the unopened flower buds are harvested, dried, and baled for ‘export. In the United: States the flowers are eround and used for making extracts containing the toxic principles, or are ground fine and used as powder. Pyrethrum loses part of its toxic ingredients in a few days when exposed to air and light. Even in airtight metal containers there is some loss of pyrethrins after several months. Pyrethrum has several distinct advantages; it is comparatively harmless to higher animals, and in dosage sufficient to kill insects leaves no poisonous residue. It is principally a contact insecticide, and one of its chief disadvantages is the lack of residual effect, i. e only insects touched with it are killed. For this reason pyrethrum has not proved satisfactory for use against the most important fruit insects, particularly where the period of attack may extend over several months. 1 Wartime conditions have led to certain restrictions on the use of pyrethrum insecticides, and these restrictions are subject to change dependent upon the supply. For up-to-date information on the subject consult the War Food Administration, Office of Materials and Facilities, Washington, D. C. 30 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE Pyrethrum is used principally against houseflies, mosquitoes, cock- roaches, body lice, leaf tiers, plant bugs, leafhoppers, mushroom flies, the imported cabbage worm, and the cabbage looper. Pyrethrum is used both in dusts and sprays. One formula for a dust for the control of the potato leafhopper on bean is made up as follows: For small For large Pyrethrum powder quantities quantities (1e3 percentepyrethrins)) =a 5 tablespoonfuls. 4 pounds. Sulfur sees i re ES - © cups. 96 pounds. Manufactured dusts which generally contain from 0.1 to 0.3 percent of pyrethrins may be purchased for use by the home gardener. The dust containing 0.3 percent pyrethrins is recommended for general purposes. When used as a spray, pyrethrum is generally applied as a diluted extract. The pyrethrins and resins are extracted with a solvent and mixed with emulsifying agents for use with water on plants, or with light kerosene for use as fly sprays in buildings, or with oil emulsions for a mosquito larvicide. Moderately concentrated pyreth- rum extracts (contaiing 2 to 3 percent of pyrethrins) properly prepared and packaged do not deteriorate rapidly. Such various concoctions should be used in accordance with the manufacturer’s recommendations. Caution.—Although the danger from human consumption of traces of pyrethrum is not great, persons allergic to ragweed in some instances are subject to attacks of hay fever when exposed to pyrethrum. ROTENONE-CONTAINING ROOTS Rotenone-containing insecticides are prepared from the roots of certain tropical and semitropical plants which, in addition to rote- none, usually contain other toxic ingredients, including toxicarol, deguelin, tephrosin, sumatrol, and a few others. Rotenone, — C.;H,.O., 1s considered the most important. The plants from which these toxic substances are derived include species of Derris (prin- cipally edliptica), which are grown extensively in Malaya and the East Indies, and species of Lonchocarpus (nicow and urucu), of South America. Experience indicates that usually there is little difference between the various roots, provided they are of equal rotenone con- tent. The rotenone content is usually 4 to 5 percent, and there is present about 214 to 3 times as much of other extractives. Rotenone, in addition to being toxic to many insects, is also poisonous to fish but is not harmful to warm-blooded animals when eaten in small amounts. Therefore, the use of ground roots is permissible on leafy vegetables which are consumed by man or domestic animals. The roots are usually ground sufficiently fine so that most of the powder will-pass through a 200-mesh screen. The powder is diluted to give a very small amount of rotenone in the mixture to be applied. It may be stirred into water and applied as a spray or mixed with some fine dust for treating infested plants. For sprays the final rotenone content may range from as low as 0.005 to 0.025 percent or higher, and for dusts from 0.5 to 1.0 percent or higher. INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 31 Liquid extracts containing the active ingredients are also available, but certain of these may lose some of their effectiveness when mixed with water. The derris and cube insecticides are sold under various trade names; but since the strength of the active ingredients may vary in the different brands, they “should be used as directed by the manufacturer. The more important uses, on vegetables, flowers, and fruits, of rote- none root powder are to control the Mexican bean beetle, cabbage caterpillars, cucumber beetles, the pea aphid, the pea weevil, the asparagus beetle, flea beetles, the cherry fruitfly, the currant worm, rose slugs, the Japanese beetle, spittle bugs on strawberries, and the iris thrips. Dusts and sprays are mixed on the basis of rotenone content. A dust usually should contain at least 0.5 percent. To mix a 0.5-percent dust, use 1214 pounds of the rotenone root powder containing 4 percent of rotenone a 871% pounds of tale, sulfur, or other diluent. If the root powder contains 5 percent of rotenone, use 10 pounds of it and 90 pounds of the diluent. For smaller quantities, weigh by ounces instead of pounds. To prepare a spray for bean beetle control, use 314 pounds of rotenone root which contains 4 percent of rotenone, or 214 pounds of rotenone root which contains 5 percent of rotenone, to 100 g gallons of water. For smaller quantities use 1 ounce of 4-percent powder to 2 gallons or 1 ounce of 5-percent powder to 214 gallons. This mix- ture will contain approximately 0.015 percent of rotenone. A spray mixture consisting of derris powder, pyrethrum extract, and sulfonated castor oil with water has been found effective against red spiders, thrips (except the gladiolus thrips) on certain flower ing plants, the cyclamen mite on chrysanthemums, aphids, cucumber beetles, tarnished plant bugs, certain species of leaf rollers, and leaf tiers. The spray is made up according to the following formula: For small For large quantities quantities Rotenone-containing root powder (containing 4 percent of byt) S11 ULC et |S ee Se eee, eee eee 1 tablespoonful. 1 pound. Pyrethrum extract (alcoholic ex- tract, containing 2 percent of LL fb 6 (<5 | pe ei ance 4 teaspoonfuls. 2 quarts. Sulfonated’ castor oil___- ___._._ 2 teaspoonfuls. 1 quart. aeons 2 Ben ee oe Oe 1 gallon. 50 gallons. In preparing this spray, add the sulfonated castor oil to the water. Next add a small quantity of this oil-and-water mixture to the derris or cube powder to make a uniform paste. Then stir the paste slowly into the remainder of the oil-and-water mixture. Finally add the pyrethrum extract to this mixture in case it is intended for the control of thrips or the cyclamen mite. For either red spiders or whiteflies, the pyrethrum may be omitted. A proprietary spreader-sticker, such as sodium oleyl] sulfate plus synthetic resinous base, may be substituted for the sulfonated castor oil in the above formula, since the oil may at times injure the petals of open flowers and also the foliage of some plants. This material is used at the rate of 34 teaspoonful per gallon, or 114 pints per 100 gallons, of spray mixture. 535593°—43——_3 32 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE A number of commercial preparations containing extracts of derris or cube, with various spreaders added, are now available and are ready for dilution with water. Derris or cube extracts should be kept in closed containers, and sprays should be apphed immediately after their preparation. These sprays lose their effectiveness within a comparatively short time after they are apphed to plants. Properly packaged and stored ground roots containing rotenone do not deteriorate appreciably for several years, nor does any deteri- oration occur when they are diluted with inert carriers like pyrophyl- lite, neutral talc, or powdered plant products and placed in closed containers in a dark, dry room. | 7 Caution.—Ground rotenone-bearing roots irritate the tender skin and the mucous membranes. RESTRICTIONS ON THE USE OF ROTENONE IN THE CONTROL OF INSECTS Under date of April 13, 1942, the War Production Board issued restrictions (Conservation Order M—133) on the use of rotenone-con- taining insecticides in order to conserve supplies of these materials which have been made scarce by war conditions. In accordance with these restrictions, the rotenone-containing insecticides should not be used against pests on eggplant, onions, peppers, squashes, pumpkins, cucumbers, cantaloups, melons, and flowering plants. To control these insects during the period of the war emergency, therefore, the alterna- tive or substitute insecticides mentioned in this publication should be. used. On January 23, 1948, the Conservation Order M-133 dealing with rotenone was amended. The amended order, which is quoted in part, redefines rotenone; places restrictions on delivery, use, production, and packaging; prescribes new forms and procedures for filing reports and making application for allocations of materials; and requires users to report supplies. As used in this order, rotenone and rotenone insecticides are defined as follows: (1) “Rotenone” means the active insecticidal ingredients of the roots of derris, cube, barbasco, tuba, or timbo. The term includes: (i) “Crude rotenone” in the form of root or of root which has been dried, broken, shredded, cut, or chipped ; (ii) “Processed rotenone” in the form of finely ground or powdered crude rotenone; also in the form of liquid or solid extracts (or resins) obtained from crude rotenone. (2) “Rotenone insecticide” means any compound containing rotenone combined with other liquid or dry materials, whether active or inert; provided that such compound is suitable for use as an insecticide. The order provides that no person shall use rotenone or any rotenone insecticide except for one or more of the following purposes: * (1) Use in the protection of the following food crops against the following insects, or the manufacture of any preparation for such use: (i) Peas—protection against the pea weevil and pea aphid. (ji) Beans—protection against the Mexican bean beetle. 2 Subsequent to this amendment the limitations on the use of rotenone were revised, and other revisions may be made as larger supplies of rotenone become available. For up-to- date information on the subject consult the War Food Administration, Office of Materials and Facilities, Washington, D. C, oeake ie INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 33 (iii) Cole crops—other than cabbage, including broccoli, brussels sprouts, cauli- flower, kohlrabi, mustard, kale, turnips, and collards—for protection against caterpillars and aphids. (iv) Sweet corn—for protection against the European corn borer. (2) Use on cattle for the specific control of the cattle grub (ox warble) or short- nosed cattle louse, or the manufacture of any insecticide for such use. (3) Any other specified use, where specifically authorized or directed by the Director General for Operations, SOAP SPRAYS Sprays made from soap are very useful, especially for small plantings or house plants. Dissolve a cubic inch of ordinary soap or 2 table- spoonfuls of soap flakes in 1 quart of water. If fish-oil soap is at hand, a rounded tablespoonful may be used. Soap sprays are useful against aphids and the younger stages of mealybugs, scale insects, whiteflies, and other soft-bodied insects, but should not be used on very young or tender plants. For use on hardy plants the amount of soap may be increased to kill larger insects. The soapy water remaining in the tub after clothes have been laundered may also be used for spraying or dipping foliage of infested house plants. When potted plants are dipped, they should be inverted and submerged only to the soil surface and then laid on their sides to drain before being set in an upright position. This will avoid saturat- ing the soil with the soap solution. House plants dipped or sprayed with concentrated soap solutions should not be placed in full sun for 24 hours, after which the foliage may be syringed with clear water and the plants returned to their former locations. Soap is used as a wetting and spreading agent with nicotine, pyre- thrum, and some other sprays. The amount of soap required in a spray mixture is regulated somewhat by water hardness. If used with lead arsenate, some soaps may increase arsenical injury to foliage. Oleates of monoethanolamine, triethanolamine, and ammonia, as well as several other soaps, have been used with mineral oil and lead arsenate in making deposit-building mixtures to obtain the heavy deposits of lead arsenate often needed for control of the codling moth. SODIUM ARSENITE Sodium arsenite (essentially NaAsO.), a white crystalline solid, is soluble in water and is, therefore, unsuitable for use on living plants. In fact, it is probably best known as a weed killer. It is more gen- erally available in liquid form containing about 32 percent of arsenic trioxide (As.O,), although it can also be purchased as a powder. Its chief use in direct control of insects is in poisoned baits (page 28), but it is used as a spray on wild vegetation to control grasshoppers. .Caution.—Sodium arsenite is a violent poison and must be stored in clearly labeled packages. SODIUM CYANIDE Sodium cyanide (NaCN) isa white, deliquescent, very poisonous salt manufactured in this country. When it is mixed with dilute sulfuric acid a reaction takes place in which the deadly hydrocyanie acid gas (HCN) is liberated. For fumigation purposes sodium cyanide 34 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE should be practically free from chloride and contain not less than 51 percent of the cyanogen radical. The chemical may be purchased in the form of “eggs”, each weighing 14 or 1 ounce. Dosages may, therefore, be easily calculated by counting the number of eggs required. Hydrocyanic acid gas is used as a fumigant to control such pests as scale insects, aphids, whiteflies, mealybugs, and thrips on plants and bulbs in fumigation vaults, greenhouses, or tents. The dosages range from 1% to 1 ounce of sodium cyanide per 1,000 cubic feet of space, with exposure periods of 1 to 5 hours or overnight. The dosage and length of exposure depend upon the plants’ tolerance to the gas. Plant tissue of all kinds is very susceptible to the action of this gas, and the margin of safety between dosages which will kill the insect and the plant is very narrow. The materials are generally combined in the proportion of 1 ounce of sodium cyanide, 114 fluid ounces of sulfuric acid, and 3 fluid ounces of water. Plant materials are fumigated in darkness and afterward protected for a short period from lght to avoid plant injury. In certain instances growing plants may be fumigated under canvas tents placed over them. For example, the boxwood leaf miner may be controlled by this method, sodium cyanide being used at the rate of 2 ounces per 100 cubic feet of space, with 3 fluid ounces of sulfuric acid and 6 ounces of water, for a period of 1 hour. The plants must be dormant and dry, and the temperature must not be too high—usually 40° to 55° F. | Caution.—In carrying out a fumigation a definite procedure and certain precautions must be followed. Sodium cyanide should, therefore, be used only by experienced fumigators thoroughly fa- millar with the methods of handling it and the hazards involved. Hydrocyanic acid gas is colorless and is one of the most deadly poisonous gases known. In case of accidental inhalation of the gas, the person affected should be kept in the open air and not allowed to exert himself. Inhalation of ammonia vapor may be of some help. All forms of cyanide are extremely poisonous and should be plainly labeled and kept in a safe place. To avoid deterioration store the material in tight containers. SODIUM FLUORIDE Sodium fluoride (NaF) is a white, very poisonous powder, soluble in water. The commercial product and commonly employed grade of powder is 94 to 97 percent pure. Sodium fluoride, undiluted, when dusted in the areas frequented by ants and roaches, except the Surinam roach, will gradually eliminate them. Sodium fluoride should not be used on plants. Caution—Since sodium fiuoride is poisonous if taken inter- nally, it should be kept in tight containers plainly marked “Poison” and stored in a dry, safe place away from foods. If the dust is inhaled, it is somewhat irritating to the respiratory passages, In New York City all sodium fluoride must be colored blue, and the National Association of Insecticide and Disinfectant Manufacturers, Inc., has gone on record favoring this practice throughout the United States. ‘This coloring is done to denote its poisonous nature. v0 eee: ee INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 39 SODIUM FLUOSILICATE Sodium fluosilicate (Na.SiF,), or sodium silicofluoride, resembles sodium fluoride and is sometimes used undiluted as a substitute for it against roaches. Sodium fluosilicate will injure plants unless use od in very dilute form. It is used chiefly as a poison in cutworm, mole cricket, or grasshopper bait. Caution.—Sodium fluosilicate is a strong poison and should be kept away from food. SULFUR Sulfur (S), a native element, is an important fungicide and insecti- cide, as well as a useful adjunct or carrier in many dust mixtures. It comes in several forms for insecticidal uses—as a finely ground powder; as a powder plus a wetting agent, called wett: able sulfur; and as flotation paste (see also Liquid ‘Lime-Sulfur and Dr y Lime- Sulfur). Much progress has been made in grinding the product, so now it is almost universally available in such fineness that almost all of it will pass through a 325- mesh screen. The most finely divided material available at low cost is the flotation sulfur paste, which is almost colloidal and sticks well to foliage. Sulfur is used for the con- trol of the potato leafhopper (on bean, aster, and dahlia), the cotton flea hopper, the tomato psyllid, red spiders, the phlox plant bug, the tarnished plant bug, and the broad mite. As a diluent for dusts it is often used with lead arsenate, pyrethrum powder, ground rotenone- containing roots, or other materials. (See Oil Dusts.) : =... 222. SiLADIESDOOMTENS 2252 2-— ==. - 9 tablespoonfuls or 4% cup_-_-_-_-_-- 4 Magnesium arsenate_------- WibeaSPOOHIWISS =—5-- wvyaplespooutaises-—» eo Se 5S 4 Parisisreen:-< 2b 3 eee 136 Geaspooniiiisis 2922 =. = +s 14 tablespoonfuls_. =. 2.2.2 =. 2 Tartar. emetic= = _ ae 1% tablespoonfuls___---------- 2 ounces or 41% tablespoonfuls__- 4 Derris powder (4 percent)___| 1 tablespoonful__------------- Stavlespoaiinis = 52-2 .- --o 21 5 tablespoontuls:< i 2 2: 15 tablespoonfuls or 1 cup-_--_-_--- 35 Cryolite 22 ee 7 deaspoontals— = 2] 522 MEapIESDOORMNS <2 Seen 2 ee) 6 Wehepore: oe ee ea aes Stablespoonfalss_.-.-=2--=2>_- Liv Gio) ee es ee ee 6 Browsesucar *- s+ 2255-58 DACA Ys ee ee ee ee 8 ounces or 1% cups-_------------ 16 Copper sulfate_2-<2_=_=2--= 614 teaspoonfuls_-_-----.------- 614 tablespoonfuls__-_........-_- 8 Hydrated lime: =: — =)... - 6stablespoonfuls®__=-22----==2- bal VG vi ea cee ie Se a. ee 12 Calcium ecaseinate___------- 2 tanlespoonutms: == === 25_ 1 SU ANCE Opec een Se as Meee 4 LORS F 1 peste a = A a 21% tablespoonfuls-_----------_- See Fc RS NE i See a a 4 1 All measurements are level, not heaped or rounded. 2 These dilutions give a rotenone content of approximately 0.005 percent in the completed spray. Fora rotenone content of 0.01 percent, the quantities given should be doubled. 3 These dilutions give a rotenone content of approximately 0.025 percent in the completed spray. TABLE 3.—Volumes of given weights of insecticidal materials, for determining amounts to be used for making up small quantities of sprays or dusts Volume of materials Volume of materials equal to— equal to— Material Maiterial 1 ounce 1 pound 1 ounce Fi pound Unit Cups - Unit Cups Bentenites=— = 22 214 tablespoonfuls_ 214 || Magnesium arsenate__| 4 tablespoonfuls__- 4 Brown sugar_____----| 34 tablespoonfuls_ 3% || Mercuric chloride__-__| 1 tablespoonful___- 1 Calcium arsenate___-- 5 tablespoonfuls___ 5 Naphthalene_________ 5 tablespoonfuls___ 5 Calcium caseinate____| 224 tablespoonfuls_ 2% || Nicotine sulfate_____- 5 teaspoonfuls_____ 2 CAEN | eae Se ae 6 tablespoonfuls___ 6 Paradichlorobenzene_| 214 tablespoonfuls_ 216 Copper sulfate (pow- | 5 teaspoonfuls __-_- 134 || Paris green_______.__- 14% tablespoonfuls_ 1% dered). Pyrethrum powder__-_| 5 tablespoonfuls__- 5 Cryoliies 52s 8 teaspoonfuls____- 224 || Soap powder_________ 6 tablespoonfuls___ 6 Derris powder-_------- 6 tablespoonfuls___ 6 Sodium arsenite______ 14% tablespoonfuls_ 1% Mlouma =. See 4 tablespoonfuls___ 4 Sulfur (superfine, | 24 tablespoonfuls_ 2144 Heliebore.. Fa: 5 tablespoonfuls__- 5 flowers of). Hydrated lime_-_-___-- 3 tablespoonfuls__-_ 3 Sulfur (wettable)____- | 814 teaspoonfuls___ 3 Kaolin 2 8. 5 .cue 4 tablespoonfuls__-_ 4 Tartar emetic____-___- 6% teaspoonfuls__-_ 2 Lead arsenate---__---- 41% tablespoonfuls_ 41% || Tobacco dust__._____- 6 tablespoonfuls___ 6 TABLE 4.—T ables of measures LIQUID MEASURE 6 milliliters =1 teaspoonful. 3 teaspoonfuls =1 tablespoonful. 2 tablespoonfuls=1 fluid ounce. 16 fluid ounces =1 pint (2 cups or 32 tablespoonfuls). 8 pints =1 gallon. EQUIVALENT QUANTITIES OF LIQUID INSECTICIDAL MATERIALS WHEN MIXING BY PARTS Dilution Quantity tome 2 Fee eit: bs of water (gallons) 1 to 400 1 to 800 1 to 1,000 1 to 1,600 1002- Ms oe ee Bee ee 1 pos i hak eee 12.8 fluid ounces------- 1g pint. 72 ths TR as 8 fluid ounces (1 cup)--| 4 fluid ounces (1% cup)-| 3.2 fluid ounces__-_-.-- 2 fluid ounces. Br ee 1.6 fluid ounces___._-.- 5 teaspoonfuls___--.... 4 teaspoonfuls___-...-- 216 teaspoonfuls. 1 oe oe 2 teaspoonfuls______-_- 1 teaspoonful___---...- 34 teaspoonful__.__...- 16 teaspoonful. 42 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE TABLE 4.—Tables of measures—Continued EQUIVALENT QUANTITIES OF LIQUID INSECTICIDAL MATERIAL FOR VARIOUS QUANTITIES OF WATER Quantity of water Quantity of material (gallons) 100222-255" Tespint aaa pints: £322.24 5 quate 2ouarts==—=—s= 1 gallon. DR ae a oles 2 fluid ounces__--- 4 fluid ounces_-_-| 8 fluid ounces___| 1 pint___________ 1 quart. ieee eee a 214 teaspoonfuls___| 5 teaspoonfuls___| 1.6 fluid ounces__| 3.2 fluid ounces__| 6.4 fluid ounces. [er eee V4 teaspoonful_____ 1 teaspoonful__-_| 2 teaspoonfuls__-| 4 teaspoonfuls___| 1.3 fluid ounces. Example: If the manufacturer recommends 1 quart to 100 gallons of water, the home gardener should use 2 teaspoonfuls to 1 gallon of water. DRY MEASURE 3 level teaspoonfuls=1 level tablespoonful. 16 ounces =1 pound. EQUIVALENT QUANTITIES OF DRY INSECTICIDAL MATERIAL FOR VARIOUS QUANTITIES OF WATER Quantity of water Quantities of material (gallons) 1002 1 pound_____ 2 pounds____| 3 pounds____} 4 pounds____] 5 pounds_________ 6 pounds. Ae ee 4 ounces____- 8 ounces____- 12 ounces____| 1 pound ____| 1 pound, 4ounces_} 1 pound, 8 ounces. epee aie ma 0.8 ounce____| 1.6 ounces___} 2.4 ounces___| 3.2 ounces___| 4 ounces_____--_-- 4.8 ounces. | ee 0.15 ounce_--| 0.3 ounce__-_| 0.5 ounce__-_| 0.6 ounce__--| 0.8 oumce__------- 1 ounce. Example: If the label on a package suggests 4 pounds per 100 gallons of water, the home gardener should use 0.6 ounce (or approximately 2 tablespoonfuls in case of lead arsenate) to 1 gallon of water. SPRAYING AND DUSTING EQUIPMENT Many types of sprayers, dusters, and accessories are obtainable for use in applying insecticides. These range in size from those suitable for the home gardener to those adapted for the large commercial grower. Certain commonly used types are discussed below. SPRAYERS Hand atomizers.—These are the familiar sprayers (fig. 1) used for applying fly sprays in the home. Usually they hold from a half pint to a quart or more of material. They are useful for spraying house plants or very small outdoor plantings and are generally available locally. Figure 1.—Hand pump atomizer. INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 43 Compressed-air sprayers—Compressed air sprayers (fig. 2) are usually made of brass or galvanized sheet steel and have a capacity ranging from 1 to 5 gallons. The sprayer consists of an airtight tank into which is clamped a pump. In operation the tank is filled with spray to about three-fourths of its capacity, and the opening is closed by a tight-fitting cap. Air is then pumped in by hand until sufficient pressure is developed to force the liquid through the hose and nozzle. The hose is usually fitted with a spray shut-off and a 1- to 5-foot exten- sion rod with nozzle. Since the pressure decreases as the spray is forced out, it is necessary to renew it by further pumping. The tank must be shaken frequently to keep the ingredients well mixed, al- though the movement of the operator causes a certain amount of agi- tation. FieurE 2.—Compressed-air sprayer. This type of sprayer is suitable for the average home gardener. By the use of extension rods low trees can be sprayed. Knapsack sprayers.—A knapsack sprayer (fig. 3) consists essentially of a force pump with an air chamber fitted to a metal tank and so de- signed that it can be carried on the back of the operator. It can be operated by one hand while the other is used to manipulate the spray rod and nozzle with which the apparatus should be equipped. A knap- sack sprayer has a capacity of about 3 to 5 gallons and a spraying range of about 25 feet when equipped with a nozzle throwing a com- pact stream of spray. It has an advantage over the compressed-air sprayer in that a higher and more uniform pressure can be maintained when the pump is kept in constant operation. Agitation is provided in some outfits by a brass plate inside of the tank which moves up and down with the pump handle. The usefulness of knapsack sprayers corresponds closely to that of compressed-air sprayers. They can, however, be used on larger plant- ings and on somewhat larger trees. MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE 4 Figure 3.—Knapsack sprayer The bucket pump.—this apparatus 1s also called a stirrup pump. It is merely a single- or double-acting pump equipped with hose and nozzle (fig. 4) which may be clamped or set in a bucket or tub con- Ficure 4+.—Bucket pump with hose, extension rod, cut-off, and nozzle This type of s sprayer is intended for | taining the liquid insecticide. Its chief shortcoming is the fact that the oper- the home gardener. ator must remain stationary while pumping INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 45 The barrel pump.—This type of sprayer has a hand-operated pump attached to a barrel or similar container for the spray. The assembled outfit is mounted on a sled or wheels (fig. 5) or loaded in a wagon or truck. In certain types, called wheelbarrow sprayers, the container is small enough so that it is mounted between handles with a single wheel in front and is pushed by the operator. Ficure 5.—Barrel pump mounted on wheels and equipped with hose, extension rod, shut-off, and nozzle. Depending upon the size of the outfit, the barrel sprayer is fairly satisfactory for spraying commercial plantings of truck, fruit, nurs- ery, or other crops. However, the operation of the pump is laborious, and it is difficult to maintain constant high pressure. Because of these facts a power outfit is to be preferred. Traction sprayers.—This type of sprayer is usually mounted on two wheels. Essentially it consists of a tank, with a pump geared to the wheels and with the nozzles usually attached to a fixed boom (fig. 6). Ordinarily these machines are horse-drawn. Pressures reaching as high as 125 to 250 pounds per square inch can be maintained, provided that the rig is in constant motion. Machines of this type were designed for spraying field crops, includ- ing potatoes and tomatoes and small fruits, where it is not necessary to make any stops, as is the case when spraying trees. For the most part traction sprayers have been replaced by power machines, the latter being much more satisfactory. Power sprayers.—These machines are so called because the pumps are driven by motors, either gasoline or electric. They range in size from small 10- to 50-gallon tank-capacity outfits, with single-cylinder pumps which maintain a pressure of 150 to 200 pounds, to large rigs 46 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE Resa Figure 6.—Traction sprayer in operation. The nozzles are arranged so as to cover the entire plant with liquid insecticides. When poisonous sprays are being used, the operator should use full face and respiratory protection. (fig. 7) for use in orchards and parks, which have a tank capacity of 400 gallons or more and multiple-cylinder pumps which maintain pres- sures up to 800 pounds. Figure 7.—Large power sprayer in action, with home-made boom attached and earrying 56 nozzles, : The small outfits are usually pulled or pushed by a workman and are used in small commercial plantings of vegetables, ornamentals, and small fruits, and in greenhouses. The larger types are either horse- or tractor-drawn, or they may be self-propelled. For use on row crops the nozzles are usually attached to a fixed boom (fig. 8) and are adjusted to spray the plants thoroughly. To spray trees or shrubs, one or more lengths of hose are attached, and the INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 47 spray is directed as desired by an operator who manipulates the spray gun or spray “broom.” Power sprayers are the most satisfactory for the commercial grower. Numerous types are available, and the individual grower can ordinarily obtain one suited to his particular needs. WO)” Y ff yy Te Ficurp 8.—Arrangement of nozzles and boom for spraying the under surfaces of the leaves. The nozzles are placed on rigid pipes, but the whole boom swings freely. DUSTERS Cheesecloth sack—When a regular duster is not available, certain insects on low-growing row crops can be controlled by shaking the powdered insecticide onto the plants from a cheesecloth or similar bag. This method is not very effective for insects which feed on the under sides of the leaves, and is wasteful. Plunger-type dusters.—The plunger type of hand duster (fig. 9) consists of a chamber for the insecticide and a cylindrical metal chamber provided with a piston, piston rod, and handle. When the handle is operated back and forth an air current is developed that passes through the second chamber containing the insecticidal dust. In some types the pump and the dust chamber are made entirely of metal, whereas in others the dust container is a glass mason jar, which is threaded so that it can be screwed onto the pump chamber. These usually have a capacity of about 1 to 2 pounds. This type of duster is well suited for dusting vegetable and orna- mental plants in the home garden. AS MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE Bellows or knapsack dusters.—This type of duster (fig. 10) is carried -on the back like a knapsack. Essentially it consists of a metal hopper for the insecticide, equipped with a bellows which when operated forces air through a discharge chamber and pipe, carrying the insecticide with it. The hopper is usually provided with a dust-feeding device. The FicurE 10.—Bellows or knapsack duster. dust is discharged in puffs with each stroke of the bellows. This type of equipment is especially suited for use on crops planted in hills. Bellows-type dusters are adapted for use in a variety of situations, from the home garden to good sized commercial plantings. However, they are probably best suited for use by commercial growers in plant- ings where the use of power equipment is not feasible, Fan or blower type of duster—In this type of duster (fig. 11) the hopper. which has a capacity of 5 to 10 pounds, depending upon the powder used, is usually located over the air chamber. An enclosed fan geared to a hand crank forces an even and continuous flow of air FIGURE 11.—F an or blower duster. | d INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 49 through a small chamber, into which the dust is fed from the hopper. Most modern types are equipped with an agitator that keeps the dust stirred within the hopper and also with an adjustable feeding device to insure an even feed through the discharge chamber. This | type of duster can be fastened to the operator by means of a body support and a waist-and-shoulder strap. The discharge pipes of some are designed so that dusting can be done either in front or to the rear of the body. This is a convenient and easily operated apparatus for use in situa- tions similar to those described for the bellows duster. Since a con- tinuous stream of dust is delivered, this type of duster is better suited for closely planted crops than for crops where the plants are widely spaced. Traction dusters—As with traction sprayers, these machines are geared to the wheels. The principal parts are the hopper for holding the dust, feeder, air chamber, fan, and discharge tubes. They range in size from small outfits pushed by the operator to larger horse- drawn machines. They are used principally on row crops and small fruits. In gen- eral the dust is delivered in the manner described above for fan or blower dusters. ‘Traction dusters are not so satisfactory as power dusters. Power dusters—These dusters are operated by gasoline engines and, like power sprayers, range in size from the small wheelbarrow ty pe (fig. 12) pushed by the operator to large horse- or tractor-drawn rigs (fig. 13). Some outfits are mounted directly on tractors. FIGURE 12.—Small power duster, pushed by hand. The essential parts are the hopper, feeder, air chamber, fan, and discharge tube or tubes. The dust mixture is carried in the hopper, from which it is fed into the dust chamber, where it is caught by ¢ strong current of air and is expelled through the flexible fuchara tubes. The apparatus should have an agitator to stir up the dust so that it will feed evenly. There should also be a device for regulating the flow of dust into the discharge chamber. Power dusters are suited 50 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE for use on plantings varying from one-half acre to many acres, depend- ing upon the size of the machine. Hoods or cloth trailers are often used behind the machine on low-growing crops to obtain better plant coverage and to reduce (often by as much as one-half) the quantity of dust required. FIGURE 13.—A power duster in operation. When poisonous dusts are being used, the operator should use full face and respiratory protection. CARE OF INSECT-CONTROL DEVICES Proper care of spraying and dusting equipment is essential to assure satisfactory performance and long life, especially during the present emergency. All equipment should be kept clean. Sprayers.—Unused spray material should be drained from spray pumps and hose at the completion of a job. The tank, hose, valves, and nozzles should be thoroughly flushed with clean water and the pump run for a few minutes to rinse thoroughly and remove all the insecticide. Unless this is done, these parts and connections may corrode or become clogged. Spray equipment should be kept in a cool, shady place to avoid rapid deterioration of gaskets, hose, and other parts. During cold weather the pump, tank, and hose should be drained of all excess liquid to avoid freezing and breaking, or the sprayer should be stored in a warm place. All unpainted metal parts that are subject to rusting should be well oiled or greased. Wooden tanks should be stored in a damp place or clean water kept in them (except where freezing temperatures occur) to prevent drying out and shrinking. It is advisable to have extra hose connections, pump gaskets, cup leathers, valves, valve seats, plungers, and other working parts on hand for prompt replacement in case a break-down occurs. Dusters—Dusters should be kept in a dry place, and, if used irreg- ularly, the excess dust should be removed after each operation and returned to the container in which it is stored. The dust will dete- riorate less rapidly in such containers, and the mechanism of the dust- ing equipment will not be subject to corrosion. Working parts should be properly lubricated. INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS ol WHEN AND HOW TO APPLY INSECTICIDES Be prepared to spray or dust whenever an insect infestation threat- ensthe crop. Where only a few plants are concerned it may be sufficient to pick off and kill the insects or to remove infested leaves. Find out what insect is present and whether an insecticide should be used; your county agent, Smith-Hughes teacher, extension entomologist, or experiment station entomologist, State department of agriculture, or the Bureau of Entomology and Plant Quarantine of the Li nited States Department of Agriculture can give you the necessary information. To get the best results in the control of insects, the spray or dust mixtures must be properly prepared, and the application must be made promptly and thoroughly with good apparatus. Disregard of these factors involves waste of material, possibly injury to the plants, and questionable results. Do not wait until the plants are seriously injured, but begin the treatment as soon as insects or damage is ob- served. Using a watering pot or whisk broom is not spraying and is a hit-or-miss method that covers the plants only partially. The ideal spray is a fine mist, and the best work is done when the entire plant is thoroughly and evenly covered with very fine droplets. In case of dusts an even and thin coating of the dust particles over the plant surfaces is desired. The best results are accomplished by directing the sprays or dusts from below to cover the under surfaces of the foliage and from above to cover the upper surfaces. It is best to stop spraying before the foliage is drenched, otherwise large dreplets will form and run off the plant, causing wastage. Spraying with a high pres- sure gives the best results. It is essential to keep the spray mixture stirred during the spraying process. The interval between applications will depend upon the weather and the habits of the insects. If rains occur soon after the plants have been sprayed or dusted, it is often necessary to repeat the treat- ment the next day or as soon thereafter as weather conditions permit. If one application does not give good control, repeat the treatment. FIRST-AID SUGGESTIONS IN CASES OF INSECTICIDAL POISONING When handling and using poison there is a possibility of accident; therefore the following instructions are given as an aid in such cases. The first step is to rush the victim to the nearest hpspital if it is within a reasonable distance, or to obtain the service of a physician as soon as possible. The physician should be informed as to the nature of the poison, the exact time elapsed since the patient received the poison or showed signs of sickness, the extent and kind of first aid that may have been administered, and medicaments available at the place of the accident. In all cases where poison has been taken through the mouth into the stomach the first effort should be directed to removing the poison as quickly as possible or to diluting it in the stomach, since a poison diluted with large quantities of fluid is not absorbed so rapidly as it is in concentrated form. Therefore, first aid to the victim should be (1) to induce vomiting and (2) to dilute the poison. When the poison is removed it can do no further damage, and vomiting may be induced by inserting the finger down the throat. It is much easier to induce vomiting when the stomach is full than when empty; therefore, to 52 MISC. PUB. 526, U. S. DEPT. OF AGRICULTURE dilute the poison in the stomach and induce vomiting, cause the patient to swallow several (4 to 7) glassfuls of any simple and readily avail- able emetic, such as those suggested by the Red Cross—soapsuds of any ordinary soap, salt water, soda water made with ordinary baking soda, lukewarm water, dishwater, or milk, particularly in the case of corrosive poisons. Al] solutions are more effective if administered when lukewarm; but if no warm water is immediately available, use cold water, so that vital time may not be lost in heating it. Caution.—Do not, under any circumstances, give any liquids to a victim who is unconscious. Keep him lying down and warm until a doctor arrives. If breathing has stopped, as from gas poisoning, artificial respiration should be resorted to, provided it is applied by someone who is competent to apply it. PROCUREMENT OF INSECTICIDES AND SUBSIDIARY MATERIALS Ordinarily insecticides, subsidiary materials, and equipment for their application may be obtained from local seed or agricultural supply stores; but if they cannot be bought locally, information re- carding sources of supply can be obtained from your county agent, Smith-Hughes teacher, State agricultural experiment station, State department of agriculture, or the Bureau of Entomology and Plant Quarantine, Agricultural Research Administration, United States Department of Agriculture, Washington, D. C. O Ss) nthe hae. 9 een Bee Petes