Stenothemus lupus, Hsiao, Yun, Okushima, Yûichi & Yang, Ping-Shih, 2016

Hsiao, Yun, Okushima, Yûichi & Yang, Ping-Shih, 2016, Review of the genus Stenothemus Bourgeois from Taiwan, with description of three new species (Coleoptera: Cantharidae) and additional distributional records of previously known species, Zootaxa 4117 (1), pp. 101-114 : 108-109

Stenothemus lupus sp. nov.

Figs. 39–40 , 43–45 , 52–53

Type material. Holotype: Ƌ, Tienchih, Kaohsiung, Taiwan, 11. I. 2014, W.-C. Liao leg. ( NMNS). Paratypes: 1 Ƌ, Tahanshan, Pingtung, Taiwan, 15. XII. 2012, W.-C. Liao leg. ( TARI); 2 Ƌ, Tahanshan, Pingtung, Taiwan, 16. XII. 2013, Y.-T. Chung leg. ( TARI); 1 ♀, Jimshuiying, Pingtung, Taiwan, 5. I. 2014, W.-C. Liao leg. ( NMNS); 1 Ƌ, 1 ♀, same data as holotype (1 in NMNS; 1 in YHC); 1 ♀, Xitou, Nantou, Taiwan, 25. I. 2015, J.-F. Hsieh (YHC); 1 Ƌ, Tahanshan, Pingtung, Taiwan, 13. XII. 2015, W.-C. Liao leg. ( NMNS).

Description. Male ( Fig. 39 ). Length: 8.50–11.00 mm (holotype: 8.50); width: 1.80–2.50 mm (holotype: 1.80). Eyes black. Head black, clypeus and vertex light brown. Antennae fuscous, with antennomeres light brown distally. Mandibles light brown, with apices darker; maxillary and labial palpomeres light yellow. Pronotum black, with large light brown marking on disc. Scutellum light brown. Elytra dark brown, with apices of humeri light yellow; meso-, metaventrites and abdomen dark brown. Coxae, trochanters, femora, tibiae and tarsi light brown distally. Body densely covered with fine yellowish pubescence; anterior margin of clypeus fringed with pale bristles; antennae, elytra and legs with some yellowish bristles intermingled with primary pubescence, but sparsely at humeri.

Head as long as wide, eyes moderately protruding, ratio of eye diameter to interocular space 1.00:2.50; dorsum slightly swollen posteriorly, depressed along anterior margin of clypeus and laterally anterior to eyes; anterior margin of clypeus arcuate, slightly emarginate medially; surface densely, finely punctate, each side with rectangular impression posterior to antennal socket; antennae long, extending to apical third of elytra, antennomere I clavate, II short and expanded apically, III–XI subcylindrical, ratio of antennomere lengths as follows: 17.0:10.0:15.0:20.5:21.0:21.0:21.0:21.5:20.0:18.5:19.0.

Pronotum subquadrate, about 0.90 times as wide as head, nearly as long as wide; anterior margin almost straight; posterior margin arcuate, but feebly indented medially; lateral margins almost straight, constricted anterior to posterior angles; anterior angles rounded; posterior angles slightly protruding and obtuse; disc swollen, with pair of rounded elevations posterolaterally; antero-lateral areas hollowed; medio-longitudinal furrow distinct in center of disc; surface matted, finely and sparsely punctate. Scutellum triangular with rounded apex. Elytra collectively about 1.7 times as wide as pronotum, about 3.0 times as long as wide, lateral margins subparallel in basal one-fifth, diverging posteriorly, reaching maximal width at apical fourth; surface densely and coarsely punctate, but fine and sparse anteriorly. Prosternal process concave apically. Mesoventrite distinctly convex medially. Legs very slender; femora nearly straight; tibiae nearly straight but somewhat bent.

Aedeagus ( Figs. 43–45 ). Ventral process of each paramere clavate, moderately expanded apically, bent inwards apically; dorsal plate of each paramere subtruncate apically, distinctly longer than ventral process, roundly, widely concave on inner side, with a pair of indistinct angular protuberances medially; each laterophyse strongly bent dorsad, apically acute, laterophyses globular, swollen basally.

Female ( Fig. 40 ). Length: 10.50–13.00 mm; width: 2.00– 2.50 mm. Similar to male. Body and pronotum wider than male; head as long as wide, eyes less protruding than in male, ratio of eye diameter to interocular space 1.00:3.35; antennae shorter than male, extending to elytral midlength, ratio of antennomere lengths as follows: 16:10:13:19:19:18:20:19:18.5:17:17. Pronotum about 1.20 times as wide as head, about 0.90 times as long as wide. Elytra collectively about 1.8 times as wide as pronotum, about 3.0 times as long as wide. Abdominal ventrite VII ( Fig. 52 ) with lateral sides rounded, bearing a broad, dark brown triangular protuberance medially along posterior margin; disc with a V-shaped macula densely punctate medially and posteriorly. Female genitalia ( Fig. 53 ) with vagina stout, with distinct folds on the surface; diverticulum thin, spiralling and very long, much longer than spermathecal duct; spermatheca with a thin and spiral tube; accessory gland thin, spiralling and very long.

Diagnosis. This new species is somewhat similar to S. taiwanus Okushima & M. Satô, 1997 but can be distinguished by: 1) its darker body and legs, black head, black pronotum, with a large light brown marking on disc, which is yellowish brown, with M-shaped dark marking on disc of pronotum in S. taiwanus ; 2) the structure of the aedeagus, especially the much longer dorsal plate, with apex bent inwards, lacking paired thin processes on the inner side, and laterophyse more slender and acute; however, the dorsal plate of each paramere is shorter, with rounded apex and a pair of thin processes on the inner side, and thicker, obtuse laterophyse in S. taiwanus ; and 3) female abdominal ventrite VII with lateral sides more rounded and protuberant triangular lobe medially along posterior margin, disc with a V-shaped dark macula densely punctate medially, which is subtruncate, sinuate at both sides of posterior margin, with smaller middle lobe in S. taiwanus .

Etymology. The specific epithet is named after the constellation “ Lupus ” which is Latin for “wolf”, a reference to the dark and inconspicuous coloration of this species, similar to that seen in wolves.

Distribution. Taiwan (endemic).

Figures

FIGURES 39 – 42. Habitus, dorsal view. 39 – 40. Stenothemus lupus sp. nov.; 41. S. gemini sp. nov.; 42. S. vulpecula sp. nov. Male holotypes: 39, 41 – 42; Female paratypes: 40. Scale bars = 5.0 mm.

FIGURES 43 – 51. Aedeagus. 43 – 45. Stenothemus lupus sp. nov.; 46 – 48. S. gemini sp. nov.; 49 – 51. S. vulpecula sp. nov. Ventral view: 43, 46, 49; Lateral view: 44, 47, 50; Dorsal view: 45, 48, 51. Scale bars: 0.5 mm.

FIGURES 52 – 53. Stenothemus lupus sp. nov. 52. Abdominal ventrite VII of female; 53. Female genitalia. Scale bar for Fig. 52 = 0.5 mm; Scale bar for Fig. 53 = 1.0 mm.