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Hylotrupini
Classification
Introduction
- The tribe Hylotrupini Zagajkevich, 1991 currently contains 1 species in 1 genus. Photographs of exemplar specimens are coming soon.
Diagnostic Features of Adults
- Body moderate-sized, between 10-40 mm; generally elongate. Eyes generally reniform, complete (not completely divided into upper and lower lobes). Antennae generally filiform, unarmed; antennae 11-segmented, short, not extending beyond tip of abdomen. Pronotum generally transverse (distinctly wider than long); lateral margins of pronotum unarmed, without distinct spines or tubercles. Elytral apices without distinct spines.
Diagnostic Features of Larvae
- Mature larva. Length up to 24 mm; maximum breadth (at prothorax) 7.5 mm. Form rather robust, slightly depressed. Head subtrapezoidal, widest well behind middle (maximum head-width 4.25 mm.). Gena somewhat shouldered, pale, smooth and with a few short, pale setae. Front margin of head pale, ferruginous, rugose. Front margin of frons rather swollen. Mouthframe completely, though rather weakly, sclerotized beneath antennae. Antenna testaceous, with second segment three times as long as third; third cylindrical, twice as long as broad; supplementary process rather attenuated, at least two-thirds as long as third segment. Mandible broad, with basal part ferruginous; apical part pitchy, shining and with a deep longitudinal, median impression. Labrum fleshy, transversely-oval and with numerous long, fine setae. Epipharynx setose only on sides. Three distinct ocelli present close together in a straight row laterad and ventrad of antennal; ocellar lens strongly protuberant; pigmented spot distinct. Hypostoma rugose, with front margin not or scarcely darker than remainder; sutures curved. Gula rather broad, slightly raised, with concave sutures. Maxilla with lobe entirely glabrous on inner margin; maxillary palp with third segment shorter than second and shorter than third segment of labial palpi; dorso-external process of palpifer slightly shorter than last segment of maxillary palpi. Labial palpi with second and third segments equal in length. Prothorax rectangular, depressed, with numerous long, fine setae; posterior half smooth, shining, with a few irregular coarse striae; median cleavage line deeply impressed. Eusternum distinct, triangular, shining, rugose and almost glabrous. Abdomen with dorsal ampullae shining, coarsely rugose (even slightly tuberculate), with posterior transverse impression distinct; median furrow rather shallow. Anal lobes sparsely setose. Pleural discs indistinct or absent. Legs with femur wider than long; femur and tibiotarsus testaceous; unguiculus ferruginous for at least apical two-thirds and strongly imbricately spinose. Spiracles with peritreme broadly ova], very thin and pale. Although there seems no doubt that this species has been correctly placed in the Callidiini according to adult and pupal characters, the larva does not conform at all satisfactorily to what would appear to be the true larval characteristics of this tribe. On the other band, larvae of certain other species of Hylotrupes approximate much more closely to the tribal characters. Craighead (1923) suggests that the exceptional characters of H. bajulus may have developed due to its unusual habitat.
Pupa. Length 14-25 mm; maximum breadth 7 mm. Head quadrate, glabrous. Mesonotum with several long, fine pale setae directed backward on each side of scutellum, which is depressed. Metanotum with numerous similar setae on each side of scutellar groove which is slightly depressed. Elytra and wings extending to fourth abdominal segment. Abdomen with tergites one to six, each with short ferruginous spines (each bearing a fine basal seta) arranged in a transverse row along anterior and posterior margins and in a broad, semi-oval group near each lateral margin. Seventh tergite very elongate and strongly tapering posteriorly; anterior two-thirds with numerous scattered, slightly stouter spines directed posteriorly; posterior third glabrous. Eighth tergite elongate, subparallel-sided and bearing numerous spines on each side of a longitudinal median groove. Ninth tergite extremely short, rugose, slightly bilobed, each lobe bearing a fine seta. Sternites smooth and glabrous. Pleura protuberant, rugose and glabrous. Legs with hind femora extending as far as fourth segment. Functional spiracles present on first five abdominal segments; peritreme broadly oval, moderately thick and slightly raised above general level of cuticle. Adapted from Duffy (1953).
Geographic Distribution of Tribe
Biology and Economic Importance
- The only species in the tribe, Hylotrupes bajulus ("old house borer"), has spread to all geographic regions and is considered a serious pest of lumber and structural timbers. This species feeds only in pine, spruce, and other coniferous woods. More information on this genus is available at: cabi.org/.
Selected References to Adult Specimens
Selected References to Larvae Specimens
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Hylotrupes bajulus
(Linnaeus, 1758); dorsal
♀ specimen
Cerambycidae:Cerambycinae:Hylotrupini
Photograph © E.H. Nearns
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