Amphimenes absensacidus, Hunting, Wesley & Yang, Man-Miao, 2019

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 : 12-16

Amphimenes absensacidus sp. n. Figs 4, 5 A–D, 11B, 12

Specific epithet.

From Latin, absens and acidus, in reference to the lack of cross striations on the intervals of the elytral disc, typical in many species of this genus and all other species known from Taiwan.

Types and other material examined.

Holotype (male) labeled “Holotype” [circular, ringed with red]; "TAIWAN: "TAIWAN: Nantou Co./Huisun Forest Station /Hotel, May 26, 2012/24.0932N, 121.0310E"; "hand coll., veg. nr./Frog Rock trail, night,/~740m, Acc. Ti-170a/Coll. W. M. Hunting"; " NCHU#/100728". 28 paratypes, 13 males and 15 females. For further details see EH Strickland Virtual Entomology Museum Database.

Type locality.

Taiwan. Huisun Forest Station, Nantou county.

Diagnosis.

Specimens of this species are distinguished from other Taiwanese Amphimenes by lacking cross striations on the elytral disc.

Description.

OBL 5.8 - 6.8 mm. Length (n = ten males, ten females): head 0.58 - 0.70, pronotum 1.08 - 1.24, elytra 3.16 - 3.80, metepisternum 0.72 - 0.84 mm; width: head 1.12 - 1.36, pronotum 1.64 - 2.04, elytra 2.17 - 2.75, metepisternum 0.44 - 0.50 mm.

Body proportions. HW/HL 1.87 - 2.14; PWM/PL 1.52 - 1.67; EL/EW 1.31 - 1.47; ML/MW 1.50 - 1.82

Color. Fig. 4. Dorsum of head piceous; clypeus piceous; labrum piceous with brunneo-piceous margins; pronotum piceous with margins markedly pale, rufo-testaceous; proepipleuron rufo-testaceous to darker; antennae rufo-brunneous to brunneous; palpi rufo-brunneous to brunneous; elytral disc piceous, margins rufo-brunneous, translucent; elytral epipleura piceous to brunneo-piceous; thoracic sclerites rufo-brunneous to piceous; abdominal sterna rufo-brunneous medially and brunneo-piceous to piceous at lateral margins; legs with trochanter and femora testaceous to rufo-testaceous, tibia rufo-testaceous to brunneo-piceous.

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

Macrosculpture. Pronotum with scattered punctures in lateral margins; elytral striae evenly punctate along length.

Pilosity. Elytra with scattered micro-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 glossy.

Head. Labrum more or less quadrate, few with slight indentation along apical margin but not bilobed; eyes distinctly convex, distinctly wider across than width of neck.

Pronotum. Lateral margins distinctly explanate, broadly rounded; posterio-lateral margins rounded; posterio-lateral fovea relatively deep; basal lobe present.

Elytra. Humeri broadly rounded; striae moderately impressed; lateral margins nearly parallel; elytral apices truncate.

Hind wings. Macropterous.

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

Abdominal sterna. Abdominal sterna IV–VI with two to four irregular punctures between fixed apical setae; abdominal sternum VII deeply bilobed.

Male genitalia. Fig. 5 A–D. Length 1.28 - 1.44 mm. Phallus with one carina from base to mid-phallus, centered when viewed ventrally. Left side of shaft distinctively enlarged medially; endophallus with distinctive form, relatively large internal endophallic sclerite (es) near apex and several endophallic lobes (el).

Female genitalia. Fig. 11B. Width 0.84 - 0.92mm. Two spermathecae, spermatheca 1 (sp1) and 2 (sp2) with ducts relatively smooth and even throughout length; One spermathecal accessory gland (sg); spermathecal gland duct (sgd) attachment site at base of spermatheca 1 duct, basal to attachment site of spermatheca 2 and associated diverticulum (div); one diverticulum, elongate.

Habitat, habits, and seasonal occurrence.

The known elevational range of A. absensacidus sp. n. is from 700 to 1850 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 from May to August. Methods of collecting include u.v. light and hand collecting at night.

Geographical distribution.

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