) 
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_ ee ee ae ee ee eee ae ae ie ae 2 we ee SS 
THE PEACH-TREE BARKBEETLE. 97 
of the egg burrow. While an extension opposite this is being made 
the males copulate with the females at this point. At other times 
the males remain between the mouth of the burrow and this niche, 
occasionally going deeper into the burrow. Copulation ordinarily 
takes place at the fork in the burrow, and has been observed a number 
of times to last as long as fifteen minutes after the cutting away of 
the bark. The female rests with the posterior end of the abdomen 
just at the edge of the fork, the male operating from the adjoining 
niche. The sole function of the male seems to be that of attending 
the female, as none has ever been observed working. 
The forks of the burrow may or may not be nearly equal in length, 
but usually they vary to quite an extent. They are, however, always 
more or less horizontal, Hf 
running around the axis 
of the hmb. (See figs. 18 
and 19.) After being fer- 
tilized the female imme- 
diately sets about deposit- 
ing eggs, and at this time 
the abdomen is very much 
swollen. During the con- 
struction of the burrow 
copulation occurs several 
times, so that the length 
of the burrow appears to 
depend upon the num- 
ber of times of copulation. AAT | 
As soon as the egg is de- Re ial 
5 Fic. 19.—Work of the peach-tree barkbeetle (Phleo- 
posited the female covers tribus liminaris) : Galleries in wood of peach tree, 
it with frass, so that the May 18, 1908, Lakeside, Ohio. Enlarged. (Orig- 
main burrow is a circular pet 
tube of sawdust, outside of which occur the eggs. The method of 
egg deposition is as follows: 
Having made the egg cell, the female backs out to the niche where, 
after turning around, she backs into the cell again, clinging to the 
side of the burrow. The egg is then placed in the cell, and after 
again turning around the female covers it with the sawdustlike frass. 
The egg cells are filled as soon as they are finished, and each is made 
as soon as the burrow has been extended far enough to make room 
for it. | 
From ten days to two weeks are necessary for the completion of 
the burrows. The males and females in the same burrow live until 
after most of the larve have developed into the next brood of beetles. 
The completed burrows of this species are more nearly equal in length 
