PINE BORERS. 733 



pitchy exiidatiou 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 alikornis Fabricius. 



Order Hymenoptera ; family UROCERiDiE. 



A large black four-wiuged fly an inch long, having some resemblance to a wasp, 

 but with a stout cylindrical body having the head and abdomen closely joined 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.) 



6(i. The yellow-banded urocerus. 



Urocerus abdominalis Harris. 



A four-wioged 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, tiuged 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 sequom Hy. Edw. 

 Order Lepidoptera ; family ^geriad.e. 



In 1881 Mr. Henry Edwards wrote us that this ^Egerian was devas- 

 tating the pine forests of Mendocino County, California, and was partic- 

 ularly destructive to Sequoia sempervirens, Pinus ponderosa, and Finns 

 lamhertiana. 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 



