gin of the fore part of the head, the eyes scarcely discernible, placed behind the insertion of the jaws, the thorax fuller than the rest of the body, the upper thorax a little larger than the next two rings taken together, more convex and without the transversal wrinkles of the abdominal rings.
The chrysalis (Fig. 9) ovoid, oblong, with head inclined towards the breast, shield wing fluted and embracing the abdomen at the sides, the feet exposed and drawn up on the ventral part of the body. Antennæ inserted in the front of the head passing below the eyes and the sides of the thorax, folding under in such a way that the end of the proboscis or club reaches to the fore feet. It is a dirty white in color with reddish eyes and jaws.
This insect is distinguished from the Hylesinus principally by the antennæ of nine joints. The first six are simple, the last three are dilated into a three-bladed club (Fig. 11). The body is convex and oval, and of a blackish brown color, and covered with an ashy yellow down. Antennæ and tarsi deep yellow, upper thorax broader than it is long, and unequally speckled; the shield wing is over twice as long as it is wide, rounded at the extremities and covering exactly the abdomen with nine lengthwise flutings delicately speckled; the feet robust and rather short, the femora of a brilliant black in color.
The Phlœtribus count two generations.
FIRST GENERATION.
In the autumn and winter each insect hides itself in a nest dug in the forks of the bearing branches (Fig. 3, 4). In the first days of spring, the insects abandon the nests to mate, after which they assault the dead branches, where the bark is very smooth, and dig a trench in which to deposit their eggs, (Fig. 1, 2,) gnawing obliquely first the bark and then the ring of the wood until they have a road from a twelfth to an eighth of an inch in width, they then retrace their steps, following always the ring of the wood. The female now commences to deposit her eggs singly to the right and left,
