MISCELLANEOUS PAPERS. 18T 



forms appear in autumn, and the females lay large numbers of micro- 

 scopic, shining, brown eggs in the interstices of the bark, or in the 

 angles formed by the branches and twigs. These egf!;s survive the cold 

 of winter, and their vitality is not impaired by any but the most pene- 

 trating or caustic washes. They hatch early in the spring, and the 

 young remain on the trauk or branches until each is sufficiently mature 

 to reproduce, when a considerable proportion find their way to the 

 roots, and each individual starts a colony. 



This insect has several natural enemies, among which a syrphus 

 fly (Pipsiza vacticans) and a chalcid {Aphelinus) are the most important. 

 They, however, seldom exist in such numbers as to keep the aphides in 

 check. 



Among the remedies are the following: Hot water, just below 

 the boiling point, 150 to 175 degrees Fahr. Before applying, loosen 

 the surface of the soil and remove a portion so as to partly expose the 

 roots; pour the hot water upon the latter and cover with clean soiL 

 This remedy is more practicable in small than large orchards. Another 

 remedy is that used extensively and with very good effect in France 

 against another root aphis, the notorious Phylloxera, namely : Bisul- 

 phide of carbon. To apply this, several small holes should be bored 

 around each tree a few inches from the trunk, and an ounce or two — 

 two or thee tablespoonfuls — of the sulphide poured into each hole and 

 the latter closed with earth as speedily as possible, and the fumes, very 

 deadly to animal life, will penetrate the soil in every direction and kill 

 the pests without injuring the roots. It must be remembered that this 

 fluid is very inflammable, and no lighted matches,pipes or cigars should 

 be brought into its neighborhood. Naphthaline in crystals has also 

 been recommended — an ouce or two buried among the roots of each 

 young tree. The best remedy, however, according to Dr. Riley, is the 

 kerosene emulsion. The formula is two gallons of kerosene to one 

 gallon of boiling hot, very strong soap-suds, the two liquids violently 

 agitated until combined into a jelly-like substance, which readily mixes 

 with water, and should be diluted, upon using, with 12 gallons of the 

 latter. This should be sprayed upon the trunks and branches of in- 

 fested trees during winter and early spring to kill the eggs and stem 

 mothers, and later should be poured among the roots after the top 

 soil has been removed. 



It is possible, however, to prevent the introduction of the root- 

 louse into the orchard. The soil should be thoroughly prepared, and 

 if it has previously been occupied by infected apple-trees, every 

 root should be removed and the land planted for one season to some 

 garden crop, or allowed to lie fallow. In the next place, the dealer 



