ORCHARD BARKBEETLES AND PINHOLE BORERS. 9 
80 to 160 eggs being placed by a female in a single chamber. Eggs (fig. 
7, ¢) from the first generation of beetles require from 17 to 20 days to 
hatch. The larve (fig. 7, d) bore at right angles away from the 
brood chamber, forming burrows from 1} to nearly 3 inches in length. 
They are white, often with a pinkish cast due to the contents of the 
digestive tract, and have a yellowish head and darker mouth parts. 
In from 25 to 30 days they attain full growth and then pupate 
within the bark. From 4 to 6 days are passed in the pupal stage 
(fig. 7, e), after which transformation to beetles takes place. The 
adults of this generation 
issue about midsummer 
(see fig. 10) and provide 
eggs for a second genera- 
tion, the beetles of which 
appear in the fall and 
hibernate as has been de- 
scribed. During the sum- 
mer and fall the two gen- 
erations overlap so that 
all stages of the insect 
may be found in trees at 
one time. 
CONTROL OF THE FRUIT- 
TREE AND PEACH- 
TREE BARKBEETLES. 
The first and most im- 
portant point in connec- 
tion with the control of 
these two species of bark- 
beetles is the elimination 
of breeding places. As has 
: Fic. 10.—Exit holes in peach limbs made by adults 
been shown, both species of the peach-tree barkbeetle. Natural size. 
breed only in unhealthy Oana) 
wood, and where there is an abundance of such wood they will 
multiply in numbers limited only by the food supply. Trees and 
branches affected as follows have been observed to be favorite breed- 
ing places: Trees dying from neglect and starvation, from attacks 
of the San Jose scale, infection of “ yellows,” injury to roots and 
base of trunk by mice and rabbits, injury by blight and sun scald, 
and other diseases of roots, trunk, and branches, and injury by round- 
headed apple-tree borers; trees whose branches have been broken 
down by storms or loads of fruit, or any agency or condition that 
will cause unhealthy or dying wood. (See figs. 11 and 12.) Such 
wood should always be eliminated, either by restoring it through 
