PINE BOREKS. 733 
pitchy exudation marking" the track of the larva from whorl to whorl 
or twig to twig. This larva also when removed from its burrow lives 
but a short time, owing to the hardening of the pitch." 
65. The white-horned urocerus. 
Urocerus albicornis Fabricius. 
Ordpr.HYMKNOPTERA ; family Urocerid-E 
A large black four- winged fly an inch long, having some resemblauce to a wasp, 
but with a stout cylindrical body having the head and abdomen closely jnined to the 
thorax, the base of the shanks and of the feet white, and also the antennae except at 
their ends, and a spot behind each eye and another on each side of the abdomen, the 
wings smoky transparent. The abdomen ends in a point shaped like the head of a 
spear, below which is a straight awl-like ovipositor about .40 long, with which it 
bores into the tree to deposit its eggs, the worm from which forms winding burrows 
in the wood, and is of a thick cylindrical form, divided into thirteen nearly equal 
segments, including the head, which is small, polished and horny, the last segment 
being largest of all and ending in a conical horn-like point, and the under side with 
three pairs of very small legs anteriorly. 
These insects vary considerably in their colors and marks, and the 
two sexes are very dissimilar. The male, according to Dr. Harris, is 
black, with a white spot behind each eye, and a flattened rust-colored 
abdomen. (Harris's Treatise, p. 427.) 
66. The yellow-banded urocerus. 
Urocerus abdominalis Harris. 
A four-winged fly similar to the foregoing, about 0.80 long, of a blue-black color 
with from two to four of the middle segments of its abdomen bright orange yellow, 
and also a broad band on the antennae and the four forward legs except at their bases, 
its wings hyaline, tinged at the tips with a smoky color. There is sometimes a yellow 
spot behind each eye, and the hind knees and some or all of the joints of the hind feet 
are usually yellow. My specimens are males, nor has any female answering to this 
been found, and I am forced to entertain suspicions that it is the true male of the 
preceding species. These insects are not common. (Harris's Treatise, p. 428.) 
67. Bembecia sequoia Hy. Edw. 
Order Lepidoptera ; family JEgeriadje. 
In 1881 Mr. Henry Edwards wrote us that this iEgerian was devas- 
tating the pine forests of Mendocino County, California, and was partic- 
ularly destructive to Sequoia sempervirens, Pinus ponderosa, and Pinus 
lambertiana. The eggs appear to be laid in the axils of the branches, 
the young caterpillar boring in a tortuous manner about its retreat, 
thus diverting the flow of the sap, and causing large resinous nodules 
to form at the place of its workings. These gradually harden, the 
branch beyond them dies, and the tree at last succumbs to its insig- 
nificant enemies. Hundreds of fine trees in the forests of the region 
indicated are to be seen in various stages of decay. A similar habit 
