Genus Stenoscelis Wollaston, 1861

[Japanese name: Kuchibuto-kikui-zômushi-zoku]

Stenoscelis Wollaston, 1861: 141

(type species: S. hylastoides Wollaston, 1861); Wollaston, 1873b (redescription); Csiki, 1936 (cataloged); Marshall, 1937 (in key; key to Palaearctic and Oriental species); Buchanan, 1948 (key to species of United states); Marshall, 1953 (key to African species); Voss, 1955 (redescription); Hustache, 1958 (established subgenus Astenoscelis); Roudier, 1958 (in key); Konishi, 1962 (revision of Japanese species); Voss, 1964 (established subgenus Hexastenoscelis); Morimoto, 1973 (in key); Decelle & Voss, 1972 (in key; redescription); Folwaczny, 1973 (in key); Zhang, 1995 (revision of Chinese species).

Dendroctonomorphus Wollaston, 1873b: 502; Csiki, 1936 (cataloged); Marshall, 1937 (synonymized).

Diagnosis. Among the other cossonine genera in the Palaearctic, Oriental and Oceanian regions, Stenoscelis is similar to Stenoscelodes Konishi, 1962, Brachytemnus Wollaston, 1873, and Beaveriola Osella, 1987 in the following character states: body short, cylindrical; rostrum wider than long; postocular constriction absent; mesosternum strongly depressed below level of metasternum. However, Stenoscelis can be separated from these genera by the upper margin of scrobe being directed to the middle or the lower margin of eye (curving downwards well in front of eye in Brachytemnus), the scutellum being present (absent in Beaveriola) and deeply immersed (not immersed in Brachytemnus), the fore coxae being almost contiguous (distinctly separated in Beaveriola), and the elytral intervals being granulate at declivity (not granulate in Stenoscelodes and Brachytemnus).

Life history. Stebbing (1914) reported the life histories of Stenoscelis himalayensis (Stebbing, 1909) and S. longifolia (Stebbing, 1908) . According to his study, in both species, one male and one (in S. himalayensis) or multiple females (in S. longifolia) jointly build a tunnel in dead wood, with females laying eggs in egg-galleries within the sapwood or heartwood. He also suggested that the tunnel is initially bored by a male, and after mating, females bore deeply into the wood and lay eggs. Sugimoto & Tado (2003) provided adults of S. gracilitarsis with wood, observing tunnels bored by adults and larval galleries radiate from the niches along adult’s tunnel. During field surveys, my colleagues and I also found adults of some species within tunnels that may have been created by them (Figs 85, 87 & 88). However, the detailed life history of Stenoscelis, including tunnel systems or mating systems, remains unclear.