194 BULLETIN NO. 62. 



EGG LAYING. 



The eggs are laid both on the leaves and on the fruit. Since 

 the publication, some years ago, of Prof. Cordley's suggestion that 

 the moth does not deposit her eggs on the young fruit, on account 

 of the pubecence, which later in the development is lost, I have been 

 much interested in observing where the eggs are laid in this respect. 

 These observations go entirely to bear out Prof. Cordley's opinion 

 and in the writer's mind it passes as a settled fact that while the 

 moth prefers to lay eggs on the fruit she will lay them on the 

 glossy surface of a leaf that is smooth rather than on the 

 felty surface of a young apple. Later in the season when the ap- 

 ples have lost their pilose coating most of the eggs are laid on the 

 fruit in preference to the leaves or some may be found in the latter 

 position. At JMissoula it has been observed that the egg is some- 

 times laid on a smooth spot on a young apple surrounded by the 

 felty pile. This habit of avoiding the hairy surfaces in depositing 

 eggs appears to be but a reasonable precaution of the parent, for if 

 deposited on the surface of the pile it would not only be in danger 

 of drying from below but also would be liable to be shed to the 

 ground along with the hairs unless it hatches before the hairs are 

 shed. Thus it has come about that various authors have recorded 

 that the eggs of the first generation are laid largely on the leaves 

 while those of the second are more common on the fruit. It has 

 been found, however, that where the fruit is scarce more eggs are 

 laid on the leaves. 



Various writers have stated that the eggs are laid at night. As 

 published in a previous bulletin of this station, the writer has seen 

 a moth busily engaged in egg laying just before sunset and under 

 the observations of IMr. Simpson it was found that for the most 

 part the eggs are laid in the late afternoon and early evening. It 

 seems entirely possible that during a season of warm eveningi the 

 eggs are laid more naturally after dark, but that if warm evenings 

 or nights do not occur the moth urged by the necessity of deposit- 

 ing her eggs may lay them in the afternoon as dusk approaches 

 rather than not at all. 



As bearing on the number of eggs laid by one female Mr. Simp- 

 son made two definite observations. In a limb cage in which one 

 moth had been placed he found 21 eggs and in another 25 eggs but 



