192 



Bulletin 176. 



orchards would suffer much more severely from borers than they do. 

 No plausible cause for this apparent discrepancy has yet beeu sug- 

 gested. Smith found that many eggs had been broken into after 

 they were laid, but could not discover the agent. Possibly many 

 unfertile eggs are laid, or the females may often die before laying 

 their full quota. 



Worth published a vei'y brief description of the egg of the peach- 

 tree borer in 1823, but it was iirst characterized in detail by Corn- 

 stock in 1880. An egg is shown enlarged at I in tigure 50 (from a 

 photograph), and in figure 51 is shown an egg greatly enlarged (from 

 a drawing). The eggs average .02 of an inch in length and are a 



little more than half as wide ; many are 

 shown natural size at r/i in figure 50. 

 They are of a light chestnut or mars 

 brown color and are subellipsoidal in 

 form, slightly fiattened with an oval- 

 shaped depression, as shown in figure 51 

 and at I in figure 50. One end of the egg 

 is either squarely or somewhat obliquely 

 truncate, with a slight depression in the 

 middle where the micropyle is located, as 

 shown in figure 50 at m, which gives a 

 much enlarged view of this end of the 



51. — Egg of peach-tree 

 bo rer greatly enlarged. 



egg- 



The whole surface of the egg is so 



'sculptured as to have the appearance of being laid with irregularly 



shaped paving stones, the stones being separated by slight ridges ; 



this peculiar sculpturing of the shell is well shown at I in figure 50, 



or in figure 51, and still better at m in figure 50. 



Several persons have seen the female moth depositing her eggs. 

 Comstock (1880) saw one female " deposit upwards of twenty eggs 

 upon different parts of the trunk of one tree, usually about one or 

 two feet from the surface of the ground, in the space of about one 

 hour. The eggs were deposited singly, and were stuck to the sur- 

 face of the bark on their sides by a gummy secretion." Smith (1898) 

 records that Walker, at Jamaica, Long Island, saw a female begin 

 laying eggs immediately after mating. She " moved about actively 



