Amphimenes asahinai Nakane

Hunting, Wesley & Yang, Man-Miao, 2019, A taxonomic review of the pericaline ground-beetles in Taiwan, with descriptions of new species (Coleoptera, Carabidae, Lebiini), ZooKeys 816, pp. 1-164 : 10-12

Amphimenes asahinai Nakane Figs 2, 3 A–D, 11A, 12

Amphimenes asahinai Nakane, 1957: 237 fig. 2; Habu 1964: 472 - 474, 477, 478; Fedorenko 2010: 14-50; Lorenz 2005: 456.

Types and other material examined.

Holotype (male) labeled: ”HOLOTYPE” [rectangular, red]; "Jujiro/Near Mt. Ari,/Formosa./VI-8 1938/Coll. Yoshio Yano"; Yoshio Yano;s/Collection/No. 7543"; "No. 2555/Yoshio Yano/Collection"; "Y. Yano’s /Collection/Type No. 443"Nakane coll./Sehu Japan/1999"; "0000000552/Sys. Ent/Hokkaido Univ./Japan [SEHU]"; " NCHU#/101135". 455 specimens, 236 males and 219 females. For further details see EH Strickland Virtual Entomology Museum Database.

Type locality.

Taiwan. The type is a specimen collected by Yoshio Yano in 1938. The label data indicates that it is from "Jujiro, near Mt. Ari". Jujiro is now referred to as Shihtzulu and Mt. Ari is Alishan, Chiayi County.

Diagnosis.

Specimens of this species are distinguished from other Taiwanese Amphimenes by being brachypterous, having a short metepisternum and more humeri with basal angles obliquely rounded.

Redescription.

OBL 5.3 - 7.6 mm. Length (n = 30 males, 30 females): head 0.50 - 0.72, pronotum 1.00 - 1.44, elytra 3.00 - 4.17, metepisternum 0.52 - 0.80 mm; width: head 0.96 - 1.32, pronotum 1.40 - 2.10, elytra 2.17 - 3.17, metepisternum 0.44 - 0.60 mm.

Body proportions. HW/HL 1.70 - 2.06; PWM/PL 1.33 - 1.50; EL/EW 1.21 - 1.38; ML/MW 1.18 - 1.42

Color. Fig. 2. Dorsum of head brunneous to brunneo-piceous; clypeus and mentum rufo-testaceous; pronotum brunneous with margins diffusely pale; proepipleuron rufo-brunneous; antennae rufo-brunneous to brunneous; palpi rufo-brunneous to brunneous; elytral disc brunneous, margins rufo-brunneous, translucent; elytral epipleura brunneous; thoracic sclerites brunneous to brunneo-piceous; abdominal sterna rufo-brunneous medially and brunneous at lateral margins; legs with trochanter and femora testaceous to rufo-testaceous, tibia rufo-testaceous to brunneous.

Microsculpture. Dorsum of head and pronotum with distinctive isodiametric mesh pattern easily visible at 50 × magnification; elytra with shallow and markedly elongate, transverse sculpticells faintly visible throughout; ventral surface of head, prosternum, proepipleuron, mesepisternum and metepisternum with sculpticells forming a moderately deep, transverse mesh.

Macrosculpture. Elytra with distinct cross-striations along length of intervals, deeper and more distinctive towards base; striae faintly punctate along length.

Pilosity. Elytra with scattered micro-punctures; striae punctures each bearing a small seta not visible at 50 × magnification.

Luster. Elytra moderately glossy to moderately dull; ventral thoracic sterna and abdominal sterna moderately dull.

Head. Labrum bilobed; eyes somewhat flattened in appearance, following contour of head.

Pronotum. Lateral margins sinuate toward base, distinctly angled from lateral setae towards base; posterio-lateral margins obtuse almost right-angled.

Elytra. Humeri narrowly rounded; striae moderately impressed; elytral disc with distinctive form at base, sloping laterally from base of stria 6 to lateral margin; lateral margin smooth, broadly rounded; elytral apices truncate.

Hind wings. Brachypterous, wings markedly reduced.

Legs. Meso-tibia with or without several shallow notches from mid-way to base along ventral surface.

Abdominal sterna. Abdominal sterna IV–VI smooth between fixed apical setae; abdominal sternum VII not bilobed.

Male genitalia. Fig. 3 A–D. Length 1.36-1.64 mm. Phallus with several carinae from base to mid-phallus, decreasing in length from center to right of center when viewed ventrally; endophallus short, distinctive form, small internal endophallic sclerite near apex.

Female genitalia. Fig. 11A. Width 0.84-0.92mm. Two spermathecae; spermatheca 1 (sp1) and 2 (sp2) with ducts ribbed and lumpy in appearance. One spermathecal accessory gland (sg); spermathecal gland duct (sgd) attachment site on spermatheca 1 duct, well beyond attachment site of spermatheca 2.

Habitat, habits, and seasonal occurrence.

The known elevational range of A. asahinai is from 500 to 2290 meters. Only five specimens of the 455 collected were from below 1000 meters and most were collected at over 1800 meters. Adults of this species are found in mixed primary and secondary forest of montane areas. Adults are crepuscular or nocturnal with most activity observed on live tree trunks at night. Specimens have been collected all year round but are most commonly collected from March to October. Methods of collecting include u.v. light, m.v. light, sweep netting, sugar baits painted on tree trunks, hand collecting, and insecticidal fogging at night. Confirmed tree species that A. asahinai has been collected from includes: Pinus morrisonicola Hayata, Neolitsea variabilima (Hayata), Schima superba Gard. and Castanopsis eyrei (Champ ex. Benth).

Geographical distribution.

Amphimenes asahinai is known only from Taiwan. See Figure 12.