Malcus planus sp. nov.

(Figs. 5, 6, 13, 14, 19, 21, 25)

Description. Head, 1 st antennal segment and callar region reddish brown. 4 th antennal segment black. Posterior part of pronotum and collar yellowish brown; median line on posterior pronotal lobe dark brown. Scutellum black, clavus yellowish brown; corium light yellowish brown, the medial part always darkened in contrast to the apical and basal portions. Membrane light yellowish brown, nearly covered with fused blackish brown patches. Legs and remaining segments of antennae yellowish brown.

Head with distinct erect hairs nearly as long as eye’s width. Labium reaching between hind coxae. Pronotum moderately declivent, flat. Anterior part of pronotum with erect hairs. Anterior half of the posterior pronotal lobe with a groove, the posterior end of the mid-line not terminated into a tubercle, posterolateral angle flat (Figs. 13 &14).

Abdominal laterotergites V and VI very minute, laterotergite V almost invisible, laterotergite VI only represented by a serrate tooth, laterotergite VII trapezoidal, margin with finely and regular teeth (Fig. 19). Membrane large, considerably surpassing the tip of abdomen.

Pygophore of normal shape without parandria, narrowing posteriorly, distal margin slightly convex (Figs. 21, 25).

Measurements. As shown in Table 1.

Type material. Holotype, ♂, China: Yunnan: Ruili City, Botanical Garden, alt: 1200m, 29.vii.2006, Xiaoxuan Tian . Paratypes, 3♂♂ 2♀♀, same data as the holotype .

Etymology. The specific name, planus, refers to the flat pronotum.

Remarks. This species closely resembles M. setosus and M. pallidus with flat pronotum, but differs from both in the erect hair and abdominal laterotergites, especially the abdominal laterotergite VII. Both M. setosus and M. pallidus have conspicuous visible abdominal laterotergites V–VII, but in M. planus only the abdominal laterotergite VII expands significantly outward. In the structure of abdominal laterotergites, M. planus is similar to M. elongatus, M. dentatus and M. nigrescens . The abdominal laterotergite VII of M. elongatus obviously bent downward in a sickle shape and the abdominal laterotergite VII of M. nigrescens and M. dentatus are very narrow, bow-shape, while in M. planus the abdominal laterotergite VII expands significantly outward, trapezoidal.

Distribution: China (Yunnan).