EXPERIMENT STATION BULLETINS. 467 



PYRETERUM, OR BUHACH. 



For use upon plants or trees any part of which is soon to be used as 

 food, pyretkruin, or buhach, will be found an effective remedy against 

 both biting and sucking insects. It can be applied in water at the rate 

 of a teaspoonful to the gallon, or as a powder, either at full strength, 

 or with from three to five times its bulk of flour or plaster. It quickly 

 loses its strength, and to be effectual should be fresh, and should be 

 kept in a tin box or glass bottle. 



For the sucking insects, which would not be affected by the arsenites, 

 kerosene, either alone, mixed with water, or as an emulsion, may be 

 used. 



KEROSENE EMULSION. 



Kerosene 1 pt. 



Soft soap 1 qt. 



Water 6 qts. 



Instead of the soft soap, two ounces of hard soap may be used. Heat 

 the soft soap until it becomes liquid, or dissolve the hard soap in a quart 

 of boiling water. Add the kerosene and agitate the mixture, using a 

 force pump, for five minutes, or until a homogeneous, creamy mass is 

 formed. Before using add six quarts of water. This will kill nearly all 

 insects with soft coverings and will not injure any except the more ten- 

 der plants. For the scale insects the amount of kerosene should be in- 

 creased. Upon dormant woody plants it may be as strong as one part 

 of kerosene to four of water and upon many of the trees while in leaf 

 it can be as strong as one to six or eight. 



KEROSENE AND WATER MECHANICAL MIXTURE. 



Owing to the labor of preparing the emulsion various pumps have 

 been made for the application of a spray of kerosene and water in a 

 mechanical mixture. Among the best are those manufactured by the 

 Deming Co., Salem, Ohio. 



Not only is the labor required in making an emulsion saved, but it 

 is even more effective as an insecticide and less likely to injure tender 

 foliage. The proportions of kerosene and water are about the same as 

 when emulsified, but the amount of kerosene can be increased for the 

 scale insects. Gasoline can be used in a similar manner. 



CLEAR KEROSENE. 



Several parties report using kerosene with effective results and with- 

 out injury to the foliage. If used at all, it should be with great care, 

 and we caution against its use upon the peach in particular. 



Just before the buds open in the spring the bark is well filled with sap, 

 and the danger of injury then is less than at other times. If the kero- 

 sene is carefully applied so that it will not run down the trunk and 

 saturate the soil about the roots, it can be used upon nearly all kinds 



