UNIVERSITY OF CALIFORNIA Agricultural Experiment Station ..,,.„_ __ ,--..,.._„-. BENJ. IDE WHEELER, President COLLEGE OF AGRICULTURE THOMAS FORSYTH HUNT, Dean and Director BERKELEY H - E - VAN norman, vice-director and dean University Farm School CIRCULAR No. 128 (April, 1915) INSECTICIDE FORMULAS By C. W. WOOD WORTH The insecticides listed below are given in the order of their importance in California. I. HYDROCYANIC ACID GAS By weight By volume Sodium cyanid (129) 1 oz. Sulfuric acid (66° Beaume, 1.84 sp. gravity) .... 2J oz. 1J fluid oz. Water 2 oz. 2 fluid oz. Place water and acid in earthenware vessel and add cyanid, or in generating machine dissolve the cyanid in water and then add to the acid, in the proportion of one part of acid to two of cyanid solution. For house fumigation, use above amounts for 130 cu. ft. (See Circular 127.) For scale insects on citrus trees, add to distance over the tent one-fifth the number of feet that this measurement is exceeded by the distance around. This gives relative size of the tree; the corresponding dose follows: 10 11 13 15 16 18 20 22 24 26 28 30 32 35 37 40 42 i I | 1 11 lh 12 2 2| 3 3J 4 4£ 5 6 7 8 9 10 44 47 50 53 56 58 61 64 ft. 12 14 16 18 20 24 28 32 36 40 oz. The above is the average dose used in this state; for stronger doses, read one or two places to the right; for weaker, to the left. Tent leakage more than .25 per cent requires strengthening the dose one space for each .05 per cent. II. ARSENICALS These are the cheapest insecticides and should be used whenever available. The following forms are on the market: Approximate per cent Relative of metallic amount arsenic to use White arsenic 75 1 Paris green 40 2 London purple 30 2^ Zinc arsenite 25 3 Lead arsenate 10 7 Neutral or basic lead arsenate 8 8 The above can be substituted in the proportion given, except that White arsenic should never be used on foliage, and in the foggy districts along the coast only the neutral lead arsenate is safe. This material is the only form perfectly safe on stone fruits. Lime is commonly added at about the rate of 5 pounds to the 100 gallons to Paris green, London purple, and zinc arsenite as a marker, so as to tell whether the spraying is evenly done and as a protection to the foliage, since burning is less liable in the presence of lime. (1) Paris green Lime Water Spray Formulas For orchards l*-2 lbs. 6 lbs. 200 gals. For gardens 1 teaspoonfu (i oz.) 3 teaspoonsful 2 gals. (2) Neutral lead arsenate Water 6-12 lbs. 1 tablespoonful (J oz.) 200 gals. 1 gal. Dust. — Paris green, London purple, and zinc arsenite are applied as a powder at the rate of 4 to 6 pounds per acre. Apply preferably while plants are moist with dew. Hydrated or air-slaked lime may be added as a marker if desired. For codling moth and most defoliating insects. Bran White arsenic Molasses Water Poisoned Baits For fields 10 lbs. 1 lb. i gal. 2 gals. For gardens 1 pint h teaspoonful 2 tablespoonsful I pint Mix arsenic and bran dry. Stir molasses and water together and then mix into bran, making a moist paste. For cutworms and grasshoppers, distribute a handful at base of each vine or tree or it may be broadcasted. Insects will only eat it when moist. When distributed by handfuls it may be gathered up and moistened again. Ant Poisons White arsenic Sal soda Sugar Water Strong for native ant; 2 OZ. 4 oz. 1 lb. 1 pt, Weak for Argentine ants rge quantity Small quantity 1 oz. 2 oz. 20 lbs. 3 gals. 1 scruple 1 teaspoonful 1 lb. 1 pt. For native ants, expose a small quantity of the strong poison. For the Argentine ant, place a sponge in a fruit jar, saturate it with the weak poison, make a few nailholes in the cover and keep jar in pantry and several others in the yard about the house. Add more poison from time to time. III. LIME SULFUR This material is sold in California at different densities, which are to be diluted as follows: 32° Beaume, dilute 1 to 9. 34° Beaume, dilute 1 to 10. For San Jose scale or other allied scales on deciduous trees during the dormant season. For peach moth, apply as the buds are expanding in the spring. Lime may be added as a marker, as with arsenicals, in which case strain in milk of lime when spray is ready for use. Home-made lime sulfur may be compounded as follows: Quicklime 33 lbs. Sulfur 66 lbs. Water 50 gals. Hydrated lime may be substituted for the quicklime, using 44 pounds. Bring the water to a boil, sift in the sulfur, add the lime and continue to boil for 45 minutes or an hour. It can be strained and used at once or allowed to settle and the clear liquid used, as in the commercial article. The above amount should be diluted to about 200 gallons. The only safe method to insure the proper strength is to use a hydrometer. This should show about 4° Beaume when ready to apply. IV. PETROLEUM OILS The grades sold for insecticide purposes are: Crude oils — Gravity Approximate flash point Crude oil 18° Beaume Crude distillate (heavy) 30 200° F. Crude distillate (light) 50 60 Asphaltum Refined oils — Kerosene 42 120 Gasoline 60 32 The density shows the average composition. The smaller the density number the slower the insecticide action and a low flash point indicates the presence of light oils, which increase the penetrating power and therefore the danger when applied to plants. Oils with high flash and high Beaume number, like kerosene, are considered most desirable, but on account of the cheapness a crude distillate, though a little heavier (with lower Beaume number), is more extensively used. Use or Undiluted Oils Gasoline applied with a brush for woolly aphis on apple. Do not use too much for fear of making dead spots under the bark. For bedbugs or borers in woodwork. Sprayed with an atomizer for clothes moths or fleas in carpets. Odor may be disguised by adding 1 per cent of nitrobenzene. Kerosene may be used the same as gasoline where the greasiness is not objectionable. For chicken lice and ticks, bedbugs, etc. For mosquito wrigglers where the cheaper distillate would be objectionable. Distillate For chicken lice and ticks when discoloration of buildings would not be objectionable. Crude Oil and Distillate Crude oil 18° 4 parts Distillate 30° 1 part For mosquito wrigglers, spread in a thin film over surface of infested water. Drainage or other permanent work should have precedence over temporary treatments. Asphaltum Make fluid by heating and paint a 6-8 inch strip about the base of the trunk for the peach tree borer. Distillate Spray Distillate 10 to 20 gals. 'Caustic soda 5 lbs. Water 200 gals. To be used only with a power sprayer and only in case it has an efficient agitator. This is necessary to make a mechanical mixture of the oil and water. The lye makes a better spreading and penetration. For the European fruit scale and similar insects, to be applied only in the dormant season. With kerosene substituted for the distillate it is possible to use as a summer spray for scale insects on citrus trees, though it is rather severe and should not be used except when the tree is well supplied with water and then least susceptible to oil injury. Miscible Oils These are also sold under various trade names. They have the appearance of oils, but become milky emulsions upon the addition of water. They are the best form of distillate spray when not prepared to apply the mechanical mixture just described. They have no advantage over the mechanical mixture and are more expensive. It is generally safe to follow the directions on the container. The emulsifier used is from 20 to 40 per cent of the total volume, therefore use one-quarter to three-quarters more material than when the straight oil is used. A miscible oil can bo made by mixing cresol soap with kerosene, distillate, or crude oil. No rule can be given, but the amount that can be combined with the soap will have to be determined by trial. Emulsions These are quite easily made and somewhat safer on foliage than miscible oils, for the reason that ordinary soap has less penetrating power than cresol soap. They are the best forms of oil spray that can be made at home, without the use of a power spray. For gardens For house plants Soap J lb. 1-inch cube Hot water 1 gal. 1 pint Kerosene 1 gal. 1 pint Pump through a spray pump or, with small amounts, use an egg beater. Dilute 1-8 for winter use for scale insects, 1-20 for use on foliage against plant lice. V. SOAPS The forms sold for insecticide purposes are fish oil soap, whale oil soap, laundry soap, dog soap, cresol soap, liquid soap, and soap powder. The last three are most convenient for making sprays. Cresol soap is too injurious to foliage to be used except as an emulsifier. Nursery Summer use Winter use stock dip Soap 1 lb. 1 lb. 2 lbs. Water 5-15 gals. 1-2 gals. 1 gal. Use twice as much of liquid soap because of the water it contains. For plant lice, home-made soaps can be produced as follows: Without rosin With rosin Water 6 gals. 25 gals. Caustic soda 2 lbs. 8 lbs. Fish oil 1| gals. 3 pints Eosin 20 lbs. Bring the water to boil, dissolve the lye and stir in the oil and rosin, boiling for about an hour. VI. MINOR INSECTICIDES Tobacco The powdered tobacco stems may be dusted generously over the plants for aphids. A decoction made by steeping one pound of tobacco stems in one gallon of water and diluting to four gallons makes a spray for the same purpose. The commercial article most used is a 40 per cent nicotine sulphate. A pint makes 200 gallons of spray. It penetrates better if a gallon of cresol soap or 10 pounds of other soap is added. PVRETHRUM The powdered flowers are used as a dust for fleas. Sulfur Sublimed or finely ground sulfur dusted thoroughly over foliage, preferably when moist with dew, for red spiders. Equal parts of hydrated lime improves the adhesiveness. Spray with 30 pounds to 200 gallons, with 15 pounds of lime if desired, or better, with 8 pounds of flour made up into cooked paste to spread and hold sulfur on foliage. Lime For pear thrips on pear, a whitewash made of 80 pounds to 100 gallons. Carbon Bisulfid For grain weevils or other insects affecting stored products. Place liquid in saucers or other shallow vessels above the material to be treated, using 1 pint to each 100 cubic feet. Time required, one to several hours. If the material to be treated is in a gas-tight space, the liquid may not be all evaporated and that which remains may be saved for later use. The liquid is inflammable and the gas explosive, therefore avoid lights. For ants, pour an ounce down the hole and close with moist earth. For ground squirrels, use the same method. (See Circular 82.) Formalin For house flies, place a small teaspoonful of the ordinary 40 per cent formal- dehyd in a saucer of water or make it up by the bottleful, one part to twenty of water. Compatibility Table — Insecticides and Fungicides* Fungicides o as as i_, s< C -— X Paris Green A-l Calcium Arsenite A Lead Arsenate A-l (Acid) Lead Arsenate A (Neutral) Zinc Arsenite ? Lime -Sulphur o> Emulsions © .s -| -J Soaps o I a ±obacco C C D D A C B A Acids D C I) Alkalies _ BCD * Arranged by Geo. P. Gray. For a discussion of the table see Mo. Bull, State Com. Hort., Vol. Ill, No. 7, p. 265; or Better Fruit, Vol. IX, No. 2, p. 9. CLASSIFICATION OF MIXTURES Class Al. — Compatible mixtures in which the chief constituents remain prac- tically unchanged but are less liable to decomposition after application or in which an undesirable constituent has been neutralized or rendered less soluble. Mixtures in which the spreading or adhesive qualities are improved are also included in this class. Class A. — Compatible mixtures in which no important- chemical or physical changes occur. Class B. — Efficient, non-injurious. Mixtures in which important chemical changes occur but the original killing or preventive properties and physical properties are not impaired and no injurious new compound is formed. Class C. — Inefficient, non-injurious. Mixtures in which important chemical or physical changes occur and render a part or all of the original ingredients inert, or less active, or physically unsuitable for use, but not necessarily injur- ious to the host of the parasite. Class D. — Dangerous mixtures. Mixtures in which important chemical changes occur and render all or a part of the original constituents injurious to the host of the parasite. It so happens t hat D stands for dangerous and the table has been so arranged that dangerous mixtures are thus easily recognized by associ- ating the letter which designates the class with the word. STATION PUBLICATIONS AVAILABLE FOR DISTRIBUTION REPORTS 1897. Resistant Vines, their Selection, Adaptation, and Grafting. Appendix to Viticultural Report for 1896. 1902. Report of the Agricultural Experiment Station for 1898-1901. 1903. Report of the Agricultural Experiment Station for 1901-03. 1904. Twenty-second Report of the Agricultural Experiment Station for 1903-04. 1914. Report of the College of Agriculture and the Agricultural Experiment Station, July, 1913-June, 1914. BULLETINS No. 168. 169. 170. 174. 177. 178. 182. 183. 184. 185. 195. 197. 198. 203. 207. 208. 211. No. 65. 68. 69. 70. 76. 79. 80. 82. 83. 84. 87. 88. 91. 92. 100. 101. 102. 106. 107. J08. No. 212. 213. 216. 225. 227. 230. 234. 240. 241. 242. 243. 244. 246. 248. 249. 250. 251. Observations on Some Vine Diseases in Sonoma County. Tolerance of the Sugar Beet for Alkali. Studies in Grasshopper Control. A New Wine-Cooling Machine. A New Method of Making Dry Red Wine. Mosquito Control. Analysis of Paris Green and Lead Arsenate. Proposed Insecticide Law. The California Tussock-Moth. Report of the Plant Pathologist to July 1, 1906. Report of Progress in Cereal Investi- gations. The California Grape Root-worm. Grape Culture in California ; Improved Methods of Wine-making; Yeast from California Grapes. The Grape Leaf-Hopper. Report of the Plant Pathologist to July 1, 1909. The Control of the Argentine Ant. The Late Blight of Celery. How to Increase the Yield of Wheat in California. CIRCULARS No. The California Insecticide Law. 109. The Prevention of Hog Cholera. The Extermination of Morning-Glory. Observations on the Status of Corn 110. Growing in California. 111. Hot Room Callusing. List of Insecticide Dealers 113. Boys' and Girls' Clubs. 114. The Common Ground Squirrels of 115. California. 116. Potato Growing Clubs. 117. Mushrooms and Toadstools. Alfalfa. 118. Advantages to the Breeder in Testing 119. his Pure-bred Cows for the Register 120. of Merit. Disinfection on the Farm. 121. Infectious Abortion and Sterility in Cows. 122. Pruning Frosted Citrus Trees. Codling Moth Control in the Sacra- 123. mento Valley. The Woolly Aphis. 124. Directions for using Anti-Hog-Cholcra 125. Serum. 126. Spraying Walnut Trees for Blight and 127. Aphis Control. 128. Grape .Tuice. California White Wheats. The Principles of Wine-making. A Progress Report upon Soil and Climatic Factors Influencing the Composition of Wheat. Tolerance of Eucalyptus for Alkali. Grape Vinegar. Enological Investigations. Red Spiders and Mites of Citrus Trees. Commercial Fertilizers. Vine Pruning in California. Part I. Humus in California Soils. The Intradermal Test for Tuberculosis in Cattle and Hogs. Utilization of Waste Oranges. Vine Pruning in California. Part II. The Economic Value of Pacific Coast Kelps. Stock Poisoning Plants of California. The Loquat. Utilization of the Nitrogen and Or- ganic Matter in Septic and Imhoff Tank Sludges. Deterioration of Lumber. Community or Local Extension Work by the High School Agricultural De- partment. Green Manuring in California. The Use of Lime and Gypsum on Cali fornia Soils. Correspondence Courses in Agriculture. Increasing the Duty of Water. Grafting Vinifera Vineyards. Silk Worm Experiments. The Selection and Cost of a Small Pumping Plant. The County Farm Bureau. Winery Directions. Potato Growing in the San Joaquin and Sacramento Deltas of California. Some Things the Prospective Settler Should Know. The Management of Strawberry Soils in Pajaro Valley. Fundamental Principles of Co-opera tion in Agriculture. Alfalfa Silage for Fattening Steers. Aphids on Grain and Cantaloupes. Spraying for the Grape Leaf Hopper. House Fumigation. Insecticide Formulas.