Xylotrechus colonus Classification Family Cerambycidae > Subfamily Cerambycinae > Tribe Clytini > Genus Xylotrechus Diagnostic Features of Larvae Larva. Form semi-robust, contracted, subcylindrical, tapering to last few abdominal segments; integument, firm, rather dull, densely covered with fine, soft, lemon-colored hairs. Head trapezoidal, gradually tapering anteriorly; mouth-frame corneous, very finely wrinkled, reddish-brown; labrum rather thick, soft, suborbicular, widest behind middle, with very short hairs; mandibles dull black, short, tapering rapidly to apex, basal piece about one-third length of apical, no fovea on outer face; first antennal joint about equal to last, much shorter than second, supplementary distinct; one distinct ocellus contiguous with base of antennae; gena tapering, not shouldered, bearing several very fine hairs. Ventral mouth-parts rather fleshy; all joints of labial and maxillary palpi subequal, basal joints of latter transverse; process of palpifer short, distinct, subfossal spine small. Prothorax rectangular, about twice as wide as long, thick; four distinct ochraceous tergal plates; lateral regions thickly beset with short orange hairs, those on sternum longer except for the large, suborbicular, glabrous eusternal spots; pronotum wider than long; median suture slightly impressed punctured and sparsely hairy anteriorly, posteriorly covered with dark-ochraceous, velvety pubescence and a posterior band on pro-eusternum; mesonotum, metanotum and anterior half of sterna also covered with velvety pubescence; ventral-latero sutures a mere notch. Legless. Abdomen: ampullae large, transverse, flat, dull, very finely granulate, surrounded by velvety pubescence; ventral bearing a longitudinal median stripe, of velvety pubescence, no distinct impressions. Pleural disc indistinct. Spiracles narrowly oval to broadly oval, peritreme thin. The larva feeds in almost all of the eastern hardwood trees. It is chiefly a bark feeder, mining between the bark and wood, rarely scoring the latter, and if the bark is thick it mines entirely in it. The life cycle is often completed from spring to early fall, or it extends over to the following season. Pupation may take place in either the bark or the sapwood. Adapted from Craighead (1923). Biology and Economic Importance Members of this tribe are known from various host plant families and several genera (e.g., Chlorophorus, Xylotrechus) are considered economically important. Species of this tribe are potentially invasive outside their native range. More information is available at the CAPS website. Selected References to Larvae Specimens Craighead, 1923