10 
and cultivated redbud (Cercis chinensis),* from which the species has 
been reared by the writer, and currant.? 
Cherry, beech, and white birch are probable food plants, although 
the beetle has not been reared from them, and elm, tulip, and cotton- 
wood have been mentioned as such, but on what authority is not clear. 
Oak is without doubt the favorite natural host tree. 
The larva differs greatly from that of the round-headed borer. Its 
name, flat-headed borer, is derived from the peculiar flat expansion of 
the second thoracic segment—which is close to the head. In color it 
is light yellow and in length measures nearly twice that of the mature 
insect. It habitually rests in a curved position, more bent usually 
than shown in the illustration (fig. 3,a@).. The pupa (d) shows the form 
of the future beetle and is of the same yellow color as the larva. 
This species inhabits practically the entire United States and the 
southern portion of Canada, being, like the preceding, a native of 
North America and injurious year after year. 
NATURAL HISTORY AND HABITS. 
The beetles make their appearance about the same time as the 
round-headed borer in regions infested by both species—after the 
middle of May in the principal apple-growing regions of the Northern 
States—and continue through the month of July and, it is said, even 
into September, the female depositing her eggs in cracks and grooves 
or under bark scales upon the trunks or branches of trees destined to 
be the future food of the larve. Most frequently several eggs are 
found together. These are yellow in color, irregularly ribbed, and 
about one-fiftieth of an inch in length.© The larva differs from the 
round-headed borer in that only a single year is required for its devel- 
opment, pupation occurring in the spring shortly before the appear- 
ance of the beetles. It differs, also, in its manner of work, living for 
the most part just beneath the bark, where it excavates broad, flat, 
and very irregular channels. Sometimes, however, it enters more 
deeply into the sap-wood. Like many other borers, it will often girdle 
a small tree, a single individual being capable of killing a small tree in 
this manner. As it approaches maturity it generally eats deeper into 
the solid heart-wood, but in spring, just before transformation, it 
works back again into the bark and there constructs its pupal chamber. 
It is said to remain in the pupa state about three weeks,” whereupon 
the beetle cuts its way out, leaving in the bark an elliptical exit hole 
which distinguishes its work from that of the round-headed borers, 
which make round holes in their exit. These holes correspond to a 
cross-section of the beetle making them. In the North the winter 
@ Formerly C. japonica. 
6 ¥. H. Hillman, Nevada Exper. Station, Bul. 36, p. 18. 
eC. V. Riley, Proc. Ent. Soc. Wash., Vol. III, p. 92. 
[Cir. 32] 
