IxJUfilOUS IXSECTS AND IIoW TO CoNTROL ThEM. 85 



Contact insecticides are effectual only when applied directly to soft 

 bodied insects. 

 EeUcbore (fresh) 1 oz., water 3 gallons. May also be applied dry. 

 Pyrethrum or insect poicder (fresh), 1 oz., water 3 gallons. 



Kerosene emulsion. Hard soap Y2 lb., boiling water 1 gallon, kerosene 

 2 gallons, dissolve soap in water, add kerosene and emulsify. Or, f6r 

 limestone regions, 2 gallons kerosene, 1 gallon sour milk, emulsify. Dilute- 

 4-25 times before using. 



Crude petroleum. A 20 per cent, mechanical emulsion has proved of 

 great value against San Jos6 scale when applied just before the buds 

 opened, and the trees were unharmed. 



Whale oil soap. 1^^ to 2 lb. to 1 gallon water for winter use; for summer 

 use, 1 lb. to at least 4 gallons water. 



I vary soap. Five-cent cake to 8 gallons water. 



Hot water, tobacco in solution or as dust are valuable contact insecticides. 



Washes for borers. One pint crude carbolic acid (i/^ pint refined), 1 

 gallon soft soap, thin with 1 gallon hot water, stir in acid, let it set over 

 night, then aid 8 gallons soft water. Or to a saturated solution of wash- 

 ing soda add soft soap to make a thick paint; this is improved by 1 pint 

 crude carbolic acid and 14 lb. paris green to 10 gallons of wash. Or in G 

 gallons saturated solution of washing soda, dissolve 1 gallon soft soap, 

 add 1 pint carbolic acid, mix thoroughly, slake enough lime in 4 gallons 

 water, so that when added, a thick whitewash will result, then add V^ Ih. 

 paris green, mix thoroughly. The latter is probably the best. Valuable 

 only to prevent egg laying on bark. 



Fumicjation. Most valuable for young nursery stock and for grains, 

 Cyanide of potassium (98 per cent, pure) 1 oz., best grade commercial sulr 

 phuric acid, 1 oz. by measure, water 3 oz. by measure, these amounts for ISd 

 cubic feet space, expose trees at least one-half hour. Prepare tight cham- 

 ber, mix acid in water by pouring acid slowly, stirring frequently, into the 

 water. Use earthen or glass vessels, and drop cyanide into the diluted 

 acid, closing chamber at once. 



Carbon bisulfid 1 lb. to 1,000 cubic feet space, place In shallow dishes 

 near top of chamber. 



These substances are deadly poisons, the acid will corrode or eat many 

 things, carbon bisulfid is inflammable and explosive in the presence of 

 any fire. Handle all with extreme care. 



