THE PEACH-TREE BARKBEETLE. 9 
THE EGG. 
The eggs of the first generation may be found about the third week 
in April, and, from that time on, the eggs of the first and second gen- 
eration can not be separated, owing to the irregular emergence of 
beetles and the irregular forming of egg burrows. Eggs can be found 
in all stages of development up to the first week in October. The 
egos of the second generation begin to appear about August 1. 
Owing to the small series of eggs observed, the following data on 
length of the egg stage are not given as conclusive: Eggs of the first 
generation require from 
17 to 20 days to hatch, 
while the eggs of the 
second generation hatch 
in about 8 to 10 days. 
The egg (fig. 20, ¢) is 
milky white when first 
deposited, being ellip- 
tical in shape, opaque, 
and measuring 0.06 mm. 
in Jength by 0.0385 mm. 
in diameter. The egg- 
shell is fairly tough and 
the eggs may be very 
easily taken out of the 
egg cells. When work- 
ing without interruption 
the female deposits from 
2 to 10 eggs each day, 
in addition to making 
the cells. 
The number ef eggs 
in ees burrows of this Fic. 20.—The peach-tree barkbeetle (Phlawotribus limi- 
species varies, since the naris) : a, b, Adult, dorsal and lateral views: c¢, egg ; 
eggs are not always de- d, larva; e, pupa. Greatly enlarged. (Original.) 
posited at equal intervals. Each brood chamber may contain between 
80 and 160 eggs. In the vicinity of Lakeside, Ohio, eggs can be found 
from April 20 until October 1. The egg burrow is not always made 
next to the sapwood, as in a tree where the bark is very thick the 
chambers are formed in the latter about one-fourth of an inch from 
its outer edge. 
THE LARVA. 
When the embryonic larva has become fully developed it lies in 
a curved position in the shell. After moving about a short time 
