Xestopus Andrewes, 1937

Zhu, Pingzhou, Kavanaugh, David H. & Liang, Hongbin, 2021, Notes on the genus Xestopus from China, with description of a new species (Carabidae, Sphodrini, Dolichina), ZooKeys 1009, pp. 139-151 : 139

Genus Xestopus Andrewes, 1937

Xestopus Andrewes 1937: 59; Morvan 1979: 41 (mentioned only); Casale 1981: 389 (key to species); Morvan 1982: 45 (described new species); Casale 1988: 138 (placed in Dolichina ); Sciaky and Facchini 1997: 235 (described new species); Sciaky and Wrase 1998: 223 (key to genera of Dolichina ); Lorenz 1998: 373 (catalogue); Hovorka and Sciaky 2003: 530 (catalogue); Lorenz 2005: 399 (catalogue); Hovorka 2017: 769 (catalogue); Schmidt and Will 2020: 336 (diagnosis).

Nepalocalathus Synonym: Nepalocalathus Habu, 1973: 100, type species Calathus kumatai Habu, 1973; Habu 1978: 302 (raised to genus rank and transferred to Dolichina ); Casale 1981: 389 (synonymized with Xestopus ).

Xestopus Synonym: Wittmerosphodrus Morvan, 1978: 100, type species Wittmerosphodrus walteri Morvan, 1978; Morvan 1979: 36 (described a new species); Casale 1981: 389 (synonymized with Xestopus ).

Type species.

Pristonychus alticola Fairmaire, 1889 (type locality: Mountain Yeomatong, North Myanmar; holotype in NZSI), by monotypy.

Diagnosis.

Among the seven genera of Dolichina , Xestopus can be distinguished from others by the following character combination: third antennomere very long, usually longer than the first two antennomeres combined; tooth of mentum bifid; pronotum more or less cordiform; elytra with microsculpture nearly isodiametric, parascutellar seta present, elytral disc without setigerous pores; lateral grooves absent on metatarsomeres I-IV; males with right paramere hooked at apex; female apical gonocoxite with one ensiform seta at external margin (in most specimens) and sensory pit absent. Detailed descriptions and a key to the genera in the subtribe Dolichina have been provided by Casale (1981) and Sciaky and Wrase (1998).

Comparisons.

This genus is most similar to the genus Dolichus Bonelli, sharing the large body size (>15 mm), but its members differ from those of the latter in having the tooth of the mentum bifid, the pronotum cordiform, elytral interval 3 without setigerous pores, and the right paramere of male genitalia apically hooked.

Distribution.

This genus includes eight species distributed along the Himalayas (two in Nepal, three in Bhutan, two in China, and one in Myanmar).

Remarks.

The type species of this genus, Xestopus alticola (Fairmaire, 1889) was described from Mount Yeomatong, northern Myanmar. In the two versions of the Catalogue of Palearctic Coleoptera ( Hovorka and Sciaky 2003; Hovorka 2017), the distribution of this species includes Sichuan and Sikkim and both these two are doubtful. The record for Sikkim was added by Andrewes (1937); however, this locality and the type locality are extremely distant from each other for a species with apterous members. In addition, the record for Sikkim maybe a different species ( Morvan 1979; Casale 1981). No other literature records have reported X. alticola from Sichuan, and, in fact, no Xestopus specimens have been found in that province during our many expeditions in Sichuan, so we also doubt the reliability of this distributional record.

Casale (1981) pointed out that the three species from Bhutan ( X. walteri (Morvan, 1978), X. bhutanensis (Morvan, 1979), and X. cordicollis (Morvan, 1979)) may represent three subspecies of a single species or eventually be combined into one species when abundant materials are available. Conversely, the male allotype and female holotype of X. nepalensis probably represent two different species, in our opinion, based on the original description and figures. The male differs from the female in having elytra with (1) rufous color in the scutellar region and along the sutural margin to mid-length, (2) the humeri more rounded, (3) the basal margination markedly sinuate, and (4) the apices more rounded and slightly oblique medially. Thus, a revision appears necessary to deal with this situation.