Megalotomus castaneus Reuter, 1888

Yi, Wenbo, Wang, Shijun, Zhang, Hufang & Bu, Wenjun, 2022, Notes on Megalotomus Fieber, 1860 in the Palaearctic Region (Hemiptera, Heteroptera, Alydidae), Zootaxa 5128 (2), pp. 211-224 : 218-219

Megalotomus castaneus Reuter, 1888

( Figs. 14–16 , 32–34 )

Megalotomus castaneus Reuter, 1888: 66 . Lectotype ( Kerzhner, 1972: 352, as Holotype): ♀, China (North), Beijing; MNHN. Hsiao, 1977: 276–277; Nonnaizab et al., 1986: 305–313; Nonnaizab, 1999: 76–77; Dolling, 2006: 38; Huang et al, 2013: 135–136.

Diagnosis. This species is recognized within the genus Megalotomus by a combination of the following characters: body relatively large, 15.0–17.0 mm in length, mostly brownish in colour; vertex black, with pale yellow midline; pronotum divided into two lobes by colour, with anterior lobe black, and posterior lobe reddish brown; posterior angles of pronotum acute and pointed, with a sharp apex; surcapsular spines of the genital capsule slightly curving, each one with a broad spine at outer margin of proximal part and a small bifurcation at apex; parameres wide and curving, each one with a conspicuous longitudinal crease at the terminal half.

Material examined. China: Hebei Province: 1 ♂, 4 ♀♀, Xiaowutaishan National Nature Reserve, Jinhekou , 1200 m, 26-July-2000, Weibing Zhu leg. ( NKUM) ; 1 ♀, ibid, Wenjun Bu leg. ( NKUM) ; 1 ♂, ibid, 1100 m, 23-July-2000, Wenjun Bu leg. ( NKUM) ; 1 ♂, Yuxian County, Xiaowutaishan National Nature Reserve , 1300 m, 2-August-2000, Peng Wang leg. ( NKUM) ; 1 ♂, ibid, 26-July-2000, Jincheng Ge leg. ( NKUM) ; 1 ♂, ibid, Shumin Zhou leg. ( NKUM) ; 1 ♀, Xiaowutaishan National Nature Reserve, Songzhikou , 1200 m, 3-August-2000, Weibing Zhu leg. ( NKUM) ; Yuxian County, Songzhikou , 1200 m, 3-August-2000, Jincheng Ge leg. ( NKUM) . Shanxi Province: 1 ♂, 1 ♀, Yangquan City, Cuifengshan Natural Scenic Spot , 37.79°N, 113.43°E, 1036 m, 22-July-2020, Wenbo Yi leg. ( XZTU) ; 2 ♂♂, Lvliang City, Wenyuhe National Wetland Park , 36.43°N, 113.37°E, 654 m, 11-August-2019, Wenbo Yi leg. ( XZTU) .

Distribution. China (Beijing, Hebei, Inner Mongolia, Shanxi).

Remarks. Based on distribution data gathered from the literature and studied specimens, M. castaneus and M. acutulus are nearly sympatric. The host plant of M. castaneus remains unknown so far.

Figures

FIGURES 8–16. Megalotomus spp., dorsal, lateral and ventral views. Figs. 8–10, M. junceus (Scopoli, 1763), female (China: Liaoning Province, Beipiao City); Figs. 11–13, M. ornaticeps (Stål, 1858), male (China: XinjiangAutonomous Region, Tacheng County, Yemenle Town); Figs. 14–16, M. castaneus Reuter, 1888, female (China: Hebei Province, Xiaowutaishan); Figs. 8, 11, 14, dorsal views; Figs. 9, 12, 15, lateral views; Figs. 10, 13, 16, ventral views. Scale in mm.

FIGURES 23–43. Male genitalia of Megalotomus spp. and Alydus calcaratus (Linnaeus, 1758). Figs. 23–25, M. angulus (Hsiao, 1965) comb. nov.; Figs. 26–28, M. junceus (Scopoli, 1763); Figs. 29–31, M. ornaticeps (Stål, 1858); Figs. 32–34, M. castaneus Reuter, 1888; Figs. 35–37, M. zaitzevi Kerzhner, 1972; Figs. 38–40, M. acutulus Liu & Liu, 1998; Figs. 41–43, Alydus calcaratus (Linnaeus, 1758); Figs. 23, 26, 29, 32, 35, 38, 41, genital capsules, dorsal view, parameres removed, pilosity only shown on left side; Figs. 24, 27, 30, 33, 36, 39, 42, left parameres, dorsal view; Figs. 25, 28, 31, 34, 37, 40, 43, same, lateral view. Scale in mm.