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Petrognathini
Classification
Introduction
- The tribe Petrognathini Blanchard, 1845 currently contains 14 species in 10 genera. Photographs of 1 exemplar specimen are currently available for this tribe.
Diagnostic Features of Adults
- Body moderate to large-sized, approximately 10-40 mm or longer; generally elongate; body without metallic reflection. Eyes generally reniform, complete (not completely divided into upper and lower lobes). Antennae filiform, unarmed; antennae long, generally extending beyond elytral apices by several segments. Head without distinct lateral or anterior projections. Pronotum shape variable, from approximately subquadrate (about as long as wide) to transverse (distinctly wider than long); lateral margins of pronotum with distinct acute spines. Mesocoxal cavity open to mesepimeron. Wings generally complete. Legs with tarsal claws smooth; claws broadly divergent (divaricate). Elytral humeri distinctly modified (angulate, elevated, or spinose) or not.
Diagnostic Features of Larvae
- Mature larva. Length up to 125 mm; maximum breadth (at prothorax) 22 mm. Head slightly depressed, subparallel-sided, widest before middle (maximum head-width 12.1 mm); frontal sutures indistinct owing to sclerotization; antennal foramen closed behind; mouthframe very strongly and broadly sclerotized, pitchy, the remainder of head capsule ferruginous; six epistomal setae present. One pair of ocelli present; lens round, strongly convex and protuberant; pigmented spot indiscernible owing to sclerotization of lens. Hypostoma feebly convex, ferruginous, with front margin broadly pitchy; sutures pitchy, incurved; gula indiscernible. Antenna 2-segmented; segment 2 slightly elongate and bearing a slender, conical, hyaline process. Maxilla with segment 3 of palp stoutly conical, about half length of segment 2. Labial palpi with segment 2 nearly two-thirds length of segment 1. Mentum distinct from submentum. Labrum transversely oval. Clypeus bearing a few bristly setae near lateral margins. Prothorax obliquely slanting, with sides diverging posteriorly; posterior part of pronotum with extremely coarse asperities which decrease in size towards posterior margin of pronotum; eusternum and sternellum coarsely asperate. Abdomen with each dorsal ampulla with two transverse impressions and four transverse rows of erect, blunt, ferruginous spines in addition to numerous scattered spines. Tergite 9 unarmed. Segment 10 bearing dense ferruginous setae, the anus a transverse cleft. Epipleurum protuberant on all segments. Pleural tubercle with a pair of large sclerotized pits. Legs vestigial. Spiracles with peritreme rather narrowly oval, extremely thick and strongly raised above general level of cuticle. Egg. Length 8.5 mm; breadth 4 mm. Form oval, strongly elongate, slightly more convex on one side. Chorion yellowish white, matt, feebly rugose. Adapted from Duffy (1957).
Geographic Distribution of Tribe
Biology and Economic Importance
- Biology info coming soon. Species of this tribe are potentially invasive outside their native range.
Selected References to Adult Specimens
Selected References to Larvae Specimens
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Petragnatha gigas
(Fabricius, 1793); dorsal
Cerambycidae:Lamiinae:Petrognathini
Photograph © E.H. Nearns
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