OAK-BORERS. 
77 
and out of a pile of oak cord- wood in the forest, May 30, under such 
circumstances as convinced me they prey upon the white oak. They 
were identified by Dr. Horn. 
Beetle. — Black, 0.25 in length or slightly less, and about a third as broad, somewhat 
flattened, clothed with fine erect gray hairs; its wing-covers with two distinct 
slender white bands which do not reach the suture, the anterior one more slender 
than the hind one and curved; the antennae and slender portions of the legs usually 
chestnut colored. 
16. The common oak clytus. 
Xylotrechus colonus (Fabr.). 
Order Coleoptera ; Family Cerambycid^e. 
Larva, with details. Plate XXII, Figs. 2, 2a. 
Mining between the bark and the wood of the oak, up and down the trunk, and 
making a broad, shallow, irregular groove about 5 mm wide; the larva, pupa, and 
beetle occurring late in May and early in June. 
I have found, in company with Mr. Calder, the larvae of this pretty 
beetle in abundance mining under the bark of a fallen (probably white) 
Fig. 26.— Xylotrechus colonus ; a, pupa; c, end of body, enlarged; the other figures represent details 
lab, of the larva, all enlarged; a', antenna; lb, labrum; md, mandible; mx, maxilla with the palpus; 
labium. — Gissler, del. 
oak, near Providence, May 26; several pupae were also found, one trans- 
forming to a beetle May 27. The mine extends up and down the trunk, 
and is of the usual form of longicorn mines, being a broad, shallow, ir- 
regularly sinuous burrow, and extending part of the way around the 
trunk, the diameter near the end of the burrow being 5 mm .* 
* Larvae of this insect were found February 25, 188-2, boring in dry wood of white 
oak at Washington, D. C. The color of the larvae is pale yellowish or whitish. A 
yellowish band crosses the posterior part of the cervical shield and is beset* with 
short, glistening, backward-directed hairs. The beetles commenced issuing July 3, 
1882. (Riley's unpublished notes.) 
