152 FOREST PROTECTION AND CONSERVATION 
accustomed, by long association. It is indeed very doubtful if the 
blister rust is as important an enemy to the production of white 
pine timber as is the pine weevil. 
The adult of the white pine weevil is a small brown beetle, about 
14 of an inch long, with two grey or white band-like markings 
across each hard, shell-like wing cover. It differs from the more 
ordinary beetles in the possession of a long snout-like extension of 
the head equal to about 14 of the body length. The insect 
usually passes the winter in the adult condition and leaves its 
hibernation quarters early in the spring and immediately flies to 
young pine trees. Here the female seeks the terminal shoot or 
leader of a tree and places her eggs under the bark of that part of 
the leader produced the preceding year. This she accomplishes by 
excavating a number of shallow pits in the bark with her biting 
jaws which are at the end of the snout, and by then reversing her 
body and placing her eggs in these cavities from the end of her 
abdomen. Wherever the leader is injured in this manner, droplets 
of pitch are exuded which soon harden, and thus indicate the lead- 
ers in which eggs have been oviposited. The depositing of eggs 
begins with the first few warm days of spring—usually during 
April—and continues actively for several weeks or a month. The 
exact season of egg-laying cannot be stated, as this varies with the 
locality, and in the same locality varies with the advancement of 
the season. Some egg-laying may occur as late as the latter part 
of June, but it is usually mostly completed by the middle of May. 
The eggs usually hatch within a period of eight or ten days, 
each producing a small white larva or grub, which feeds voraciously 
under the bark of the terminal shoot, eating the cambium, the 
essential growth-producing portion of the tree. Usually the eggs 
are deposited in the upper part of the last year’s growth and the 
grubs work downward, destroying the entire inner bark and com- 
pletely killing the tissue as they proceed. As they become larger, 
the larvze eat deeper and deeper into the surface of the sapwood 
and finally, in their last larval stage when they have reached about 
their full growth, they burrow into the wood, usually in the lower 
part of a terminal shoot. There they construct small oval cham- 
bers about one-third of an inch long, which are covered with par- 
tially chewed up bits of wood, known as “chip-cocoons.” Within 
these cocoons which may lie either near the surface of the sapwood 
or in the pith, each larva changes into the stage known 
as the pupa, which requires no food and is capable only of 
feeble movements of the abdomen. The insect remains in 
