Diagnosis
Pronotum distinctly elongated and cylindrical, its anterior corners inflated, resulting in obliquely rectangular shape dorsally. Scutellum missing, elytral bases costate and ofte curved. Elytral declivity sharply truncated, often with rich armature.
Distribution
Palaeotropical.
Biology
Most species preferentially colonize Dipterocarpaceae or Fagaceae.
Taxonomy
Due to many derived features, Webbia, Arixyleborus, Schedlia and Cryptoxyleborus have been commonly treated as tribe Webbini (Browne, 1961). Classification traditionally based on number of segmants in antennal funicle, but the number varies.
Detailed description
Eyes deeply emarginate, sometimes almost disjunct, upper part smaller than lower part, or as large as lower part. Antennal club appears than tall, type three (with segment 1 straight or convex). Segment 1 of club anteriad smaller than 2 and 3 combined, its margin straight (may be slightly concave or convex) on anterior face, mostly costate, may appear softer on posterior side. Segment 2 visible on both sides of club, third segment of club absent or visible on posterior side of club. Segment 1 of antennal funicle shorter than pedicel, funicle composed of 2 or 3 segments, scapus regularly thick. Frons above epistoma mostly smooth, alutaceous, with minor punctures. Submentum deeply impressed, shaped as very narrow triangle. Anterior edge of pronotum with no conspicuous row of serrations (serrations no different than on pronotal slope). Pronotum from lateral view long, flat, convex frontally (type B). From dorsal view elongated and quadrate or subquadrate (type 8), or long, subrectangular (type A). Pronotal disc shining or smoothly alutaceous, with small punctures, lateral edge of pronotum obliquely costate. Procoxae contiguous, prosternal posterocoxal process short and conical, or flat and inconspicuous. Tuft on pronotal basis associated with mesonotal mycangium absent, but setae on elytral bases associated with elytral mycangium present. Scutellum not visible. Elytral bases curved, costate due to presence of elytral mycangium. Elytral disc longer than declivity, flat, punctures on elytral disc in strial lines (confused in many Asian species). Lateral profile of elytral declivity truncated, sometimes with costa or carina or teeth on edge, dorsal profile of elytral apex truncated. Elytral declivity with few setae or scales, not conspicuously pubescent. Declivity surrounded by elevated costa or a row of tubercles, declivity often with large projections. First interstriae parallel. Protibiae very slender, slightly broader only at distal end, posterior side inflated and granulate. Protibial denticles small, numerous, bases of denticles not enlarged, protibial margin rounded. Color variable, uniformly dark brown, or pronotum dark but elytra white (semitransparent), or with a whitish patch. Length: 2.1-3.5 mm.
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