26 



on the fruit, and that he has never seen an egg- of tlie first generation 

 upon tlie fruit in the field. 



The apparent contradictious of these observations ma}^ be accounted 

 for by the fact that they were made upon the eggs of different gener- 

 ations of the insect. The writer has found that in Idaho but few of 

 the eggs of the first generation are laid upon the fruit. . In one limb 

 cage a moth laid 21 eggs, only one of which was upon the fruit; and 

 in another cage 24 eggs were laid and only 2 were upon the fruit. 

 Very few eggs of this generation were observed to have been laid 

 upon the fruit in the field. Professor Cordley suggests that the moth 

 does not lay eggs upon the young fruit on account of the pubescence, 

 which is afterwards lost. This is most probably the cause. In the 

 field one can often find fruit, surrounded by leaves, upon which there 

 are no eggf^ while several ma}^ be found upon the upper surface of 

 the leaves. 



A good percentage of the eggs of the second generation are laid 

 upon the fruit in the field. When the fruit is scarce a larger num])er is 

 found upon the leaves. The average of several rough countings in the 

 field gave an average of about 50 per cent laid upon the fruit. Breed- 

 ing records show that out of 175 eggs of this generation in limb cages 

 on inclosed branches and fruit there were 71 eggs upon the leaves, 

 95 upon the fruit, and 9 upon the twigs. Very few eggs are laid upon 

 the underside of the leaves, and it seems that the moth much prefers 

 a smooth surface upon which to oviposit. 



We may therefore conclude that the eggs of the first generation are 

 for the most part laid upon the leaves, while the majority of those of 

 the second l)rood may be found upon the fruit. 



WHEN THE EGGS ARE LAID. 



Various writers have stated that the eggs were laid at night. 

 Cooley records that he observed a moth depositing eggs at about sun- 

 set. The writer's observations show that the oviposition for the most 

 part is accomplished in the late afternoon or early evening, while a 

 single observation shows an egg to have l)een laid sometime between 

 9 and 12 o'clock in the morning. 



THE NUMBER OF I<:GGS LAID BY ONE FEMALE. 



There is probably less definite data on this point than on any other 

 in the life history of the insect. Many guesses have been ventured as 

 to the number of eggs that one female will la}", var3nng from 12 to 

 300 and over. LeBaron found from 10 to 60 eggs, with an average 

 of 50, in various stages of development, in the ovaries of the female at 

 the time of emergence. He adds that if all the undeveloped eggs 

 came to maturity this number must be increased. Matthew Cooke 

 said that he had a vial in his possession in which a codling moth laid 85 



