3H 
Journal of Agricultural Research 
Vol. XXVI. No. 7 
The beetles are somewhat sluggish and evidently do not move about 
a great deal under natural conditions. In color they resemble the bark 
of the trees upon which they rest, and they are hard to find in the woods. 
The writer has never been able to obtain an adult specimen except by 
rearing. When confined in cages the beetles gnaw the bark freely from 
white oak twigs, and when supplied with sufficient of this kind of food 
they live from three to five weeks. 
The beetles issue from the wood late in May and early in June. At 
French Creek, W. Va., where beetles have been reared for several succes¬ 
sive seasons, the first emergence record is May 25 and the last June 1. 
Within a week or ten days after emergence the beetles begin ovipositing. 
In preparing a place for her egg the female gnaws a circular concavity 
from 6 to 12 mm. in diameter in the bark (PI. 1, A). In the center of 
this rather conspicuous scar she inserts her ovipositor and deposits a 
single egg between the bark and wood. Of about twenty eggs observed 
in their natural positions, all were placed with the long axis parallel 
to the grain of the wood and were directly above the oviposition scar 
in the bark (PI. 1 B, C). The distance from the entrance hole to the 
near end of the egg was uniformly about 1 mm. The space between the 
egg and the hole is filled with a brownish, gluelike substance which 
becomes hard when dry. 
The egg (PI. 1, B, C) of the oak sapling borer is elongate, yellowish 
white, parchmentlike, and wrinkled. The dimensions average 6 mm. 
long by 2 mm. wide. When the egg is removed from its position in the 
tree the impress of the wood grains usually shows distinctly on its surface. 
Beetles confined in the insectary oviposited freely in sections cut from 
the trunks of young white oak saplings and also in white oak bushes in 
the woods when confined over them. In one young white oak over 
which females were caged, 12 egg punctures were made. Of these 
punctures, 11 were within 4 inches of the ground and 1 was 15 inches 
above the ground. One lot of 5 females laid a total of 30 eggs, or 6 per 
individual. No definite data were obtained as to the time required by 
the egg for hatching, but general observations indicated an incubation 
period of about three weeks. 
LARVA 
Immediately after hatching the larva begins to feed in the bark and 
soon after that to eject sawdustlike castings through the oviposition 
wound and other small openings which it eats to the surface. During 
the second season of feeding these castings are thrown out near the ground 
and often form small, conspicuous heaps at the base of the tree. The 
larval period covers three years, and, in some cases, probably four 
or five years. 
Individuals of various sizes may be found in the trees at any season of 
the year. The smaller specimens are usually located just beneath the 
bark, while the larger ones are deeper in the wood. At all stages of 
their growth the larvae are slow of movement, but they show great 
strength in burrowing through the hard wood and in tearing off loose 
strings of wood for bedding their pupal quarters. 
During its last summer in the tree the larva excavates a gallery 
extending several inches up the trunk and forms a roomy pupal chamber 
at the upper end (PI. 1, D). This is entirely within the hard wood of the 
tree. The gallery below the chamber is packed with excelsiorlike wood 
fiber (PI. 1, D; 2, A) through which moisture may drain. At the upper 
