April, '19] APPLE PLANT LICE: DISCUSSION 141 



The success of most problems in insect suppression work rests prin- 

 cipally on good business management and entomologists should not be 

 slow in recognizing this fact. 



Vice-President E. C. Cotton: This completes the program of 

 the horticultural inspectors. 



In the absence of the President, I will call for the next paper, 



THE MORPHOLOGY, BEHAVIOR AND SUSCEPTIBILITY OF 

 THE EGGS OF THREE IMPORTED APPLE PLANT LICE 



By Alvah Peterson, New Brunswick, N. J. 



(Withdrawn for publication elsewhere) 



Vice-President E. C. Cotton: The paper is open for discussion 

 now. 



Mr. P. J. Parrott: As I understand the speaker, you make the 

 application of lime sulphur solely to destroy the eggs. 



Mr. Alvah Peterson: No, because at that period the eggs are 

 hatching and the combination wall kill the nymphs and the eggs. 



Mr. p. J. Parrott: In New York we are advising our farmers to 

 hold back the spraying, because we aim at the nymphs. 



Mr. Alvah Peterson: In New Jersey the eggs have not all 

 hatched at a time w'hen we apply the material. Aphis avence in our 

 state hatches ten days before Aphis sorbi. To wait until the eggs are 

 all hatched would be too late. 



Mr. C. p. Gillette: Through how long a period did you find the 

 eggs of any one species hatching normally? 



Mr. Alvah Peterson: Ten days — usually less than that. If you 

 have a warm spell during the hatching period, they will hatch in four 

 or five days, but if it is cold and wet the hatching period may extend 

 over a period of ten days for one species. 



Mr. p. J. Parrott: In your field experiments, when the trees 

 have been thoroughly sprayed at the time indicated by your third 

 picture, did you have any difficulty in getting complete killing of the 

 insects? 



Mr. Alvah Peterson: I can give you an example of that in one 

 orchard where the man was very thorough in his work. We tried the 

 nicotine combined Avith the lime sulphur, and even though tliis man was 

 very thorough in his work, he did not get 100 per cent, (^ur experi- 

 ments also showed that the eggs of Aphis sorhi and /*"//// arc not as 

 susceptible to sprays as arenas. 



