26 
on the fruit, and that he has never seen an ego- of the first generation 
upon the fruit in the field. 
The apparent contradictions of these observations may 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 probabh^ the cause. In the 
field one can often find fruit, surrounded l)y leaves, upon which there 
are no Qgg^, while several may be found upon the upper surface of 
the leaves. 
A good percentage of the ogg^ of the second genei'ation are laid 
upon the fruit in the field. When the fruit is scarce a larger numl^er is 
found upon the leaves. The average of several rough countings in the 
field gave an average of aliout 50 per cent laid upon the fi-uit. Breed- 
ing records show that out of 175 eggs of this genei'ation in liml) cages 
on inclosed branches and fruit there were 71 eggs upon the leaves, 
95 upon the fruit, and upon the twigs. Very few eggi^ are laid upon 
the underside of the leaves, and it seems that the moth much prefers 
a smootli surface upon which to oviposit. 
We mav 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 brood may be found upon the fruit. 
WHEN THJ: EC4GS ARE LAID. 
Various writers have stated that the eggs were laid at night. 
Coole}' 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 o))servation shows an Qgg to have been laid sometime between 
9 and 12 o'clock in the morning. 
THE NUMBER OF EGGS LAID BY ONE FEMALE. 
There is probabh^ less definite data on this point than on any other 
in the life history of the insect. Man}' guesses have been ventured as 
to the number of eggs that one female will lay, varymg from 12 to 
300 and over. LeBaron found from 1:0 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 
