Neolygus machanensis new species

(Fig. 1 H, Figs. 2−4)

Diagnosis. Recognized by the generally olive, oval body somewhat tinged with red (Fig. 1 H); moderate size; darkened apical 1/3 of clypeus (Fig. 2), inner part of clavus and apical part of corium (Fig. 1 H); and strikingly modified form of the male endosoma (Fig. 4).

Description. Holotype 3: Body generally olive, oval, widely tinged with red or brown; dorsal surface shining, with uniformly distributed, silky, reclining pubescence. Head polished; vertex comparatively wide, with a narrow, transverse carina basally; apical 1/3 of clypeus infuscate. Antenna pale brown; apical 1/4 of segment II dark brown; segment III dark brown, filiform. Labium shiny pale reddish-brown, reaching but not exceeding apex of metacoxa; apical part of segment IV darkened. Pronotum minutely punctate; scutellum shallowly and transversely wrinkled. Hemelytron shiny, somewhat oily; inner part of clavus and apical part of corium darkened; cuneus about twice as long as wide; membrane smoky brown. All coxae and legs pale brown; tibial spines reddish-brown. Male genitalia (Figs. 3, 4): Parameres as in basic form of Neolygus; left paramere C-shaped, with weak apical protuberance on sensory lobe; right paramere with short, weakly curved hypophysis (Fig. 3). Endosoma highly modified in shape; spiculum [Fig. 4 (a)] and ventral sclerite [Fig. 4 (b)] each reduced to a spinulate, membranous lobe. Female: Unknown.

Measurements. Holotype 3: Total body length 4.35; head width across eyes 1.06; vertex width 0.32; lengths of antennal segments IIV 0.57, 1.71, 0.95,? [missing]; labial length 1.71; basal pronotal width 1.73; width across hemelytra 1.94; lengths of metafemur, tibia and tarsus 1.81, 2. 53, 0.57.

Etymology. Named for the type locality, Machan in Chitwan National Park.

Distribution. S. Nepal (Terai).

Biology. One male adult (holotype) was collected from inflorescences of Mallotus sp. ( Euphorbiaceae). No other information is currently available.

Remarks. This new species is superficially similar to N. honshuensis (Linnavuori) and N. tsugaruensis (Yasunaga) from Japan, but the genitalic structure of N. machanensis is markedly different from those of any known congeners. In particular, the endosoma represents the most basic form within the genus.

The placement of machanensis in Neolygus is based on the general appearance, vertex with the transverse basal carina, and the form of male genitalia (endosoma with “loop” and left paramere with protuberant apical portion of the sensory lobe). We consider the reduced sclerites of the endosoma to be the most basic form as the fundamental lobes are homologous [Fig. 4 (a), (b)]. As no significant apomorphy has been found, it is prudent to place our new species in Neolygus at present.

Holotype: 3, NEPAL: Makawanpur Dist. (Terai): Chitwan National Park, Machan, 7°32'06"N, 84°44'17"E, 270 m, on Mallotus sp., 9 Nov 2005, T. Yasunaga (AMNH _PBI 00379481) (NMTU).