34 



THE EEPOliT OF THE 



No. 36 



they were placed on small pear trees — French seedlings — grown in flower pots 

 and were then confined by means of lantern globes. The insects mated readily 

 and deposited their eggs on the seedlings. Large numbers of eggs of known age 

 were in this way readily secured. 



Period. OP Incubation. The duration of incubation of the egg was obtained 

 from the " check " experiments, which will be referred to later, and was found 

 to vary to no considerable extent under the fairly uniform greenhouse temperatures. 

 In fourteen out of sixteen experiments it varied from nine to eleven days. The 

 exceptional periods of incubation were respectively eight days and twelve days. 



EXPEKIMENTS WITH CoNTACT INSECTICIDES. 



Batches of eggs, at different stages of development from newly-laid to those 

 en the point of hatching, were sprayed by means of an atomizer with four different 

 dilutions of lime-sulphur wash; soluble sulphur and hydrated lime; lime-sulphur 

 and starch; and lime-sulphur and Black Leaf 40. The results were as follows: 



LIM&SULPHUR WASH. 

 Table I — Eiffect of Lime-;Sulphub, 1-10, 1.027 sp. gr. on Psylxa Eggs. 



Table II — Effect of Lime-Sulphub, 1-9, 1.029, sp. or. on Psylla Eggs. 



Table III — Effect of Lime-Sulphur, 1-8, 1.032 sp. gr. on Psylla Eggs. 



