EFFECTS OF SPRAYS ON APHIS EGGS. 29 



thought that some iv<niir(Mneiils should 1h' iiiiuli' to pi'cvi'iit such stock 

 being transmitted. 



Mr. KirkLand stated that the insect was common in ^lassachu- 

 setts and some of the nurseries were badly infested. 



Professor Craig called attention to the fact that poplars were unde- 

 sirable shade trees in the East, and raised the question as to whether 

 this insect was not a blessing in disguise if it destroyed them. In 

 the Northwest, where other trees Avould not grow, they were needed. 

 In the East they should only be used for temporary planting: there- 

 fore it might be better to leave the growing of them to northwestern 

 nurserymen. 



]\rr. Burgess remarked that poplars were undesirable shade trees, 

 and that in East CleA'eland, Ohio, where this borer had become estab- 

 lished, and the San Jose and oyster-shell scales seriously attacked 

 them, an ordinance had been passed prohibiting their planting. 



The following pajier was ]iresented : 



EFFECTS OF SPRAYS ON APHIS EGGS. 



r.y II. K. I1()1)(;kiss. Gciicru, X. Y. 



The apple aphides have been unusually abundant for several years 

 in the orchards and nurseries of New York. The species repre- 

 sented are Aphis mall Fab., Slphocoryne aveiup Fab., and Aphis 

 malifolia' Fitch. The methods commonly used by our nurserymen in 

 fighting the pests on apple blocks are, either dipping the stocks in oil 

 emulsions or soapy solutions, or the direct application of these sprays 

 to the foliage. In years when these pests are most abundant the treat- 

 ment of the trees in this manner has not been entirely successful 

 owing to belated applications and the protection derived by the in- 

 sects from the curling of the leaves. As eggs on the nursery stock, 

 especially the seedlings, have been numerous, and therefore quite 

 conspicuous, nurserymen have often asked what Avould be the etfects 

 of contact sprays on eggs. As there Avas abundant opportunity for 

 this Avork. experiments were conducted during the autumn and winter 

 of 190-t, 1905. and lOOG for the purpose of determining the compara- 

 tive effects of different contact sprays upon aphis eggs. 



For the purpose of the experiment, seedling apple stocks, upon 

 Avliich large numbers of eggs had l)een deposited, Avere selected. As 

 it Avas necessary to liaA'e the conditions of the experiment under 

 control, the trees, upon their removal from the nursery blocks, Avere 

 grown in a greenhouse. The number of trees under obserA^ation was 

 :V2i\ and these divided into fiA^e lots. All the sprays Avere tested in 

 each lot. The sprays employed Avere the sulphur Avashes, kerosene, 

 kerosene emulsion, Avhale-oil soap, crude oil, Scalecide, Kil-o-Scale, 



