Tylonotus bimaculatus Classification Family Cerambycidae > Subfamily Cerambycinae > Tribe Hesperophanini > Genus Tylonotus Diagnostic Features of Larvae Larva. Form subcylindrical, elongate, slender; integument rather firm, shining, sparsely covered with short, light yellowish hairs. Head roundly rectangular, almost suborbicular; mouth-frame corneous, smooth, greenish brown; clypeus long as labrum, latter transversely oval, somewhat stalked, ciliate in front: mandibles rather slender, entirely black, basal piece about one-half length of distal; antenna slender, first and second joints subequal, or first a little shorter, third shorter; supplementary minute; ocellus large, clear, projecting, contiguous to antennae, not enclosed by gena (i.e., gena not shouldered). Ventral mouth-parts: palpi slender, last joint of maxillary palpus slightly longer than second, about equal to or slightly shorter than last labial; process of palpifer distinct. Prothorax about two-thirds wider than long, four tergal plates distinct, ochraceous; pronotum slightly wider than long, anteriorly sparsely hairy, hairs short, posteriorly finely and regularly striate, median suture not impressed; sternum narrow, eusternal spots contiguous, glabrous, wrinkled, shining; ventro-lateral suture a mere notch; sternellar fold not passing spiracles, distinct at extremities. Mesonotum having scutellum distinct; metanotum with a transverse impression. Legs very short, three-jointed, basal joints transverse, shorter than maxillary palpi. Abdominal segments elongate, space between ampullae (intersegmental skin) twice wider than ampullae; dorsal ampullae projecting, oval, finely alutaceous, shining, marked by two lateral and two transverse impressions, setting off a fusiform area. Pleural discs indistinct. Spiracles broadly oval to orbicular, peritreme distinct. Pupa: Pronotum beset with a few short stiff hairs on a papilla-like base; mesonotum glabrous, metanotum having a few very small points on posterior half; two groups of small conical points on the posterior half of each abdominal tergum, becoming larger posteriorly and very large on seventh and eighth, the latter having six on the hind margin. Adapted from Craighead (1923). Biology and Economic Importance The larva usually is found attacking living ash (Fraxinus) trees, and it often kills them. It mines beneath the bark and wood, first in the larger branches and later in the main trunk as the trees become weakened. It is often associated with several species of cossids. Immature larvae and pupae can be found at the same time, indicating a life-cycle extending over several years. It occasionally attacks privet hedges (Ligustrum), causing the death of the plants. Adapted from Craighead (1923). Selected References to Larvae Specimens Craighead, 1923