Anabaxis chathamensis, Shen & Leschen, 2018

Shen, Jia-Wei & Leschen, Richard A. B., 2018, Review and clinal variation of New Zealand Anabaxis Raffray (Coleoptera: Staphylinidae: Pselaphinae: Goniaceritae), Zootaxa 4382 (3), pp. 531-552 : 537-538

Anabaxis chathamensis sp. nov.

Fig. 4

Diagnosis. Body length almost 2.0 mm. Tergite IV (visible tergite I) with discal carinae longer than half length of tergite IV; median antebasal fovea slightly smaller than lateral antebasal foveae. Mesotrochanter bearing slender spine as long as ventral length of trochanter. Aedeagus with symmetrical elongate and thin parameres, curved and nearly in contact, but not fused, with subapical lobes bearing 2 pairs of lateral setae, apical setae longer than basal setae; internal sac with dense patches of sclerites on internal surface, two twisted sclerotized slender and long laminae present at basal two-thirds.

Description (n = 3). Body length 1.75‒1.80 mm; color reddish-brown, antennal club, palpi and tarsi lighter. Dorsal vestiture uniseriate (head and pronotum) or biseriate (elytra and abdomen), average length longer than length of eye ( Fig. 4A ). Head transverse, slightly wider than long at eye level, dorsal vestiture long and uniseriate; frontal fovea setose, vertexal foveae asetose. Eyes well-developed, rounded and protuberant, with 17‒19 facets. Pronotum slightly convex and subglobular, slightly wider than long, about 1.1X as long as wide (PL/PW = 0.37‒ 0.38/ 0.41‒0.43 mm), wider than head at eye level, widest at anterior two-fifths; dorsal vestiture long and uniseriate; lateral antebasal foveae setose; median antebasal fovea slightly smaller than lateral antebasal foveae; antebasal sulcus weakly impressed. Elytra slightly wider than long, about 1.2X as long as wide (EL/EW = 0.5 3‒0.55/ 0.65‒ 0.67 mm), widest near middle; dorsal vestiture biseriate with shorter scattered decumbent setae and with 2 longitudinal rows of longer suberect setae; each elytron with 2 basal foveae ( Fig. 4B ); posterior margins moderately sinuate. Abdomen convex, slightly narrower than elytra at base; dorsal vestiture biseriate with shorter scattered decumbent setae and with 2 longitudinal rows of longer suberect setae; tergite IV (first visible tergite) with discal carinae extending three-fifths of tergal length. Male. Eyes with 17‒18 facets. Mesotrochanters with slender spine as long as ventral length of trochanter ( Fig. 4C ); mesotibiae modified by small apical spine about one-fourth length of mesotarsal claw ( Fig. 4D ). Aedeagus ( Figs 4E‒4G ) 0.38‒0.39 mm long; with symmetrical elongate and thin parameres, curved and nearly in contact, but not fused, with subapical lobes bearing 2 pairs of lateral setae, apical setae longer than basal setae; internal sac with posterior area with dense patches of small sclerites and pair of long sinuate sclerites laterally and two long and slender sclerotized laminae twisted at basal two-thirds. Female. Eyes with around 19 facets. Mesotrochanters and apical mesotibiae unmodified.

Comments. This species is similar to A. electrica and can be distinguished from it based on the large body size. Both A. chathamensis and A. electrica can be readily separated from the similar-looking species A. foveolata by having the discal carinae longer than half the length of tergite 4.

Etymology. The specific epithet is derived from its geographical distribution, Chatham Island.

Distribution. New Zealand: Offshore Islands: CH.

Type material examined. Holotype: ♂ ( NZAC), specimen entire, glued on a card, aedeagus mounted on acetate: CHATHAM IS., NZ, Awatotara , 16.Feb.1967, G. Kuschel, litter 67/123 // HOLOTYPE Anabaxis chathamensis Shen & Leschen 2017 . Paratypes: 2 exs (1 ♂, 1 ♀), same data as holotype .

Figures

FIGURE 4. Diagnostic features of Anabaxis chathamensis sp. n. A) Habitus. B) Elytra. C) Mesoventrite and mesocoxae. D) Mesotibia. E) Aedeagus, in dorsal view. F) Same, in ventral view. G) Same, in lateral view. Scales: 0.15 mm, except A = 0.3 mm.