Triotemnus Wollaston

Knizek, Milos, 2010, Five new species of Triotemnus (Coleoptera, Curculionidae, Scolytinae) from Morocco and Yemen, ZooKeys 56, pp. 191-206 : 193

Triotemnus Wollaston

Cladoctoporcus Schedl, 1975. Type species Cladoctoporcus scrofa Schedl, 1975

Type species.

Triotemnus subretusus Wollaston, 1864

Note.

The position of the genus Triotemnus Wollaston within the higher systematics of bark beetles has changed frequently since its origin. The very first attempt to range the genus within the higher systematics was made by Ferrari 1867, who recognized 6 groups of scolytids and Triotemnus was placed into Group 5 - Tomicides. Later, many different authors placed the Triotemnus in different tribes, but three main transfers were particularly important. Hagedorn 1908 suggested that the genus belongs to the family Crypturgidae , followed by Hopkins 1915, which ranked it at subfamily level. This was followed by Schedl 1932, which placed it into the tribe Crypturgini LeConte, 1876. Later it was transferred to the tribe Thamnurgini Nüsslin, 1911 by Balachowsky 1949a and afterwards into Dryocoetini Lindemann, 1876 by Wood 1986, in which it is remaining in the most modern system and the most important recent papers until now, with one exception of Pfeffer 1995, which followed Balachowsky 1949a. There is only one synonymy at the generic level, the monobasic genus Cladoctoporcus Schedl, 1975 was synonymized by Wood (1984). All other species currently included in the genus were originally described in Triotemnus , except Triotemnus grangeri (Peyerimhoff, 1919), which was originally described under the genus Lymantor Løvendal, 1889 and was transferred to Triotemnus by Peyerimhoff in 1949.

Diagnosis.

Length 1.2 - 2.3 mm, slender, cylindrical body form, reddish to dark brown, antennae and legs lighter. Male frons flattened to concave. Eyes emarginate on anterior margin around the antennal insertion. Each mandible with short or long pointed tooth-like process directed upward. Antennal funicle 4- or 5-segmented (3-segmented in Triotemnus scrofa ), antennal club longitudinally oval, usually with two sutures in apical part on anterior side. Pronotum oval or cylindrical, longer than wide, feebly declivous anteriorly, distinctly punctured, usually with impunctate median longitudinal area, not armed on basal margin. Scutellum visible, rather small, flush with elytra. Elytra cylindrical, sometimes widened or narrowed posteriorly, more or less deeply punctured in striae, finely punctured in interstriae, interstriae flat, usually smooth or minutely granulate, elytral declivity regularly rounded or flattened, sometimes with distinct lateral edges. Vestiture usually of long erected hair-like setae, these setae may be longer anteriorly, laterally and posteriorly. Procoxae contiguous, lateral margin of protibia armed by 4-5 socketed teeth. Female similar to male, except frons slightly convex, mandibles without the tooth-like processes.

Triotemnus Wollaston, 1864 differs from closely related genera (e.g. Thamnurgus Eichhoff, 1864, Xylocleptes Ferrari, 1867 and Lymantor Løvendal, 1889) mainly by modified frons in males with tooth-like processes on mandibles, feebly if at all declivous pronotum, which is unarmed on anterior margin. Tiarophorus Schreiner, 1882 has much longer pronotum and strongly, but differently modified frons in males and 6-segmented antennal funicle. Some species ranged in Tiarophorus ( Wood and Bright 1992) are recently considered under Pseudothamnurgus Eggers, 1912 (e.g. Pfeffer 1995). Solving the relationship of this genus/species with Triotemnus remains for the future study. Taphronurgus Reitter, 1913 has no tooth-like processes on mandibles in males. The most similar Cynanchophagus Aksent’ev, 1987 has much longer pronotum and 7-9 socketed protibial teeth ( Mandelshtam et al. 2006).