448 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 11 
before each molt the larvse fasten the case to the plant surface in the 
same manner as they do at hibernation and before pupating turn 
around inside the case so that the head of the pupa shall lie away from 
the plant surface. 
Biological Records 
i 
Adult Emergence. In the cages in 1909, adults issued as early as 
May 18 and as late as June 25. Emergence reached its maximum 
between May 29 and June 4, and by June 1 half the total number (125) 
of moths under observation had emerged. In 1910 emergence took 
place on dates practically similar to those the year before. In 1911 
and 1912 the emergence was slightly later, while in 1916 it occurred 
between May 9 and June 3. 
Habits of the Moths , and Egg Deposition. The moths are present from 
about the middle of May to the middle of July. They are rarely seen 
flying in the sunlight and when disturbed on the trees they soon seek 
refuge from the light. How long the moths may live in nature is not 
known, but in cages in which there was no food they existed for as 
much as a week. 
The eggs are deposited on both sides of the leaf, but mostly on the 
upper surface. Deposition has been observed to take place through¬ 
out the day. On July 9, 1909, 146 apricot leaves were examined, and 
it was found that 431 eggs were on the upper side and 134 on the under 
side. Eggs were found on the upper side of 102 leaves and on the 
lower side of 56. On the upper side the greatest number of eggs per 
leaf was 22, on the lower side 8. There were on the average 3 eggs on 
the upper side of each leaf and .92 on the under side. On the same 
date there were 28 recently hatched larvse on the upper sides, and 171 
on the lower sides, of the same leaves. The locations of the eggshells 
from which these larvse had issued were not noted but as the larvse upon 
hatching mostly seek the under side of the leaf it is doubtful if the 
relative positions of the eggs would have been materially changed had 
the shells been counted. The leaves above mentioned were taken 
from caged trees and were much more heavily infested than has ever 
been observed in nature. 
Incubation. The following table indicates the period of incubation 
in 1910 at San Jose, California. 
A total of 244 eggs passed the incubation stage in an average of 26.1 
days, the maximum and minimum being respectively 30 and 18 days. 
Five hundred and ten eggs were laid under observation and thus almost 
48 per cent hatched. The dark head of the larva is visible about 4 
days before hatching. 
