96 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
With the first warm weather in spring—as early as the last of March 
in the latitude of Lakeside, Ohio—the beetles begin cutting their way 
out from their hibernation cells. They do not immediately leave these, 
but remain from four days to a week or more, most of them feeding 
for a while and then migrating to trees, 
wood piles, and brush heaps, or to any- 
thing upon which they can feed and in 
which make brood chambers. 
ELE ADU 
HABITS. 
The beetles fly but little during the 
morning hours, migrating from tree to 
tree for the most part between the hours 
of noon and night. During the day the 
beetles move about on the trees, the 
females seeking places in which to bur- 
row and the males searching for burrows 
already started in which the usuaily 
accompanying male is lacking. After 
nightfall flight and movement over the 
tree cease. 
The male beetles probably commence 
feeding as soon as they cut their way 
out of the pupal cell, and continue to 
feed more or less as long as they live. 
When in the brood chamber they ex- 
crete a brown bead-like frass, the food 
for this sex evidently being cut loose 
and passed back by the female. The 
female commences feeding as soon as 
she has cut into the edge of the bark, 
and feeds until she is too feeble to form 
egg cells. 
The burrows of Phlewotribus liminaris 
can be very easily distinguished from 
those of Scolytus rugulosus, both from 
RXG. 18." Work of the peach tree ~ the: outside. and soheahe icide aclmnmas 
barkbeetle (Phlaotribus  limi- i 
naris): Galleries in limb of bark. The opening of the burrow of 
eaten November 20, 1908 the former as ery easily distinguished 
from the fact that the exudation from 
the burrow is held together by a fine, apparently silklike thread, 
Hu 
ih 
which is secreted by both male and female. This holds the exudation 
over and partly in the mouth of the burrow. After going into the 
sapwood the female constructs a niche which later forms an arm 
Gabe. eds! Lhe eee ie isis 
