Lathrobium (Lathrobium) follitum, Assing, 2010

Assing, Volker, 2010, On the Lathrobiina of Taiwan (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 60 (2), pp. 301-361 : 314

Lathrobium (Lathrobium) follitum sp. n. ( Figs 41-48 )

Type material:

Holotype ♂: " Taiwan, Pingtung Hsien, Peitawushan, above Kuai-Ku Hut , 2750 m, 22. V.91, A. Smetana [ T89 ] / Holotypus ♂ Lathrobium follitum sp. n., det. V. Assing 2010" (cSme). Paratypes: 1 ♂, 3 ♀ ♀: " Taiwan, Pingtung Hsien, Peitawushan, Kuai-Ku Hut , 2130 m, 27.IV.1992, A. Smetana [ T101 ]" (cSme, cAss); 1 ♀: " Taiwan, Pingtung Hsien, Peitawushan, Kuai-Ku Hut, 2135 m, 30.IV.1992, A. Smetana [ T108 ]" (cSme); 1 ♀: " Taiwan, Pingtung Hsien, Peitawushan, Kuai-Ku Hut, 2120 m, 27.IV.1992, A. Smetana [ T104 ]" (cSme); 1 ♀: " Taiwan, Pingtung Hsien, Peitawushan, Kuai-Ku Hut, 2325 m, 23. V.91, A. Smetana [ T88 ]" (cSme) .

Description:

Body length 4.8-5.7 mm; habitus as in Fig. 41 . Externally highly similar to L. involutum , except for the darker average coloration, the somewhat broader body, the pronounced microsculpture on the head, the less oblong pronotum, and the broader elytra ( Fig. 42 ). Coloration of forebody reddish to brown; elytra sometimes weakly bicoloured, brown with yellowish-brown posterior margins.

Pronotum approximately 1.25 times as long as wide.

♂: posterior margin of sternite VII weakly concave, pubescence not distinctly modified ( Fig. 43 ); sternite VIII approximately as long as wide, posterior excision shallow, broad, and situated almost in the middle of posterior margin, its depth barely 1/10 the length of sternite ( Fig. 44 ); aedeagus almost 1.0 mm long, with very long, slender, subapically hooked ventral process and with internal structures of distinctive shape, long internal structure with enormous basal portion ( Fig. 45 ).

♀: tergite VIII distinctly oblong, 1.40-1.45 times as long as wide, posterior margin distinctly produced in the middle ( Fig. 46 ), latero-ventral parts weakly developed, not meeting ventrally; sternite VIII 1.35-1.40 times as long as broad, only indistincty longer than tergite VIII, distinctly produced and almost angled posteriorly ( Fig. 47 ); tergite X approximately twice as long as tergite IX in the middle ( Fig. 48 ).

Comparative notes:

Based on the similar external and sexual characters, L. follitum belongs to the L. involutum group. From other species of this group, it is distinguished particularly by the completely different morphology of the aedeagus (ventral process, internal structures) and by the shape of the female tergite VIII. It is additionally separated from most of them by the slightly broader body.

Etymology:

The specific epithet (Latin, adjective derived from follis: bellows, balloon, etc.) refers to the enormous basal portion of the long internal structure of the aedeagus.

Distribution and natural history:

The species is probably endemic to the Peitawushan, Pingtung Hsien, southern Taiwan; its distribution at least partially overlaps with that of L. extraculum . As far as is currently known, the Peitawushan is the only mountain range hosting two species of the L. involutum group. The type specimens were sifted from leaf litter, moss, moist to wet vegetation, and other debris in a natural broadleaved forest at altitudes of 2120-2750 m.

Figures

Figs 41-48: Lathrobium follitum sp. n.: habitus (41); forebody (42); male sternite VII (43); male sternite VIII (44); aedeagus in lateral view (45); female tergite VIII (46); female sternite VIII (47); female tergites IX-X (48). Scale bars: 41-42: 1.0 mm; 43-44, 46-48: 0.5 mm; 45: 0.2 mm.