Amphicrossus kabitae Dagupta and Pal, 2019

Dasgupta, Jhikmik & Pal, Tarun Kumar, 2019, Three New Species of Amphicrossus Erichson, 1843 (Coleoptera: Nitidulidae: Amphicrossinae) from Northeast India, with a Review of the Genus in the Region, The Coleopterists Bulletin 73 (2), pp. 307-320 : 312-314

2. Amphicrossus kabitae Dagupta and Pal , new species

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Type Material. Holotype male, genitalia dissected and mounted on cover slip and pinned with the holotype. Original label: “ INDIA: Arunachal Pradesh, Tirap Dist. [presently Changlang dist.], Zero Camp, 28 km-O-Miao, 27.4847° N, 96.2084° E, 1 ex., 20.XII.1983, S. Biswas and party leg.” . Paratypes: 2 ƋƋ, Bengal (presently Jharkhand state), Rajmahal , 25.0543° N, 87.8309° E, 6. VII. 1909, N. Annandale leg., rotten patch on living tree trunk, Det. by A. Grouvelle as A. discolor Erichson [ZSI Reg. No. 1288/16] .

Description. Oval, globose, ventrally subdepressed, dark brown, dorsum finely punctate ( Fig. 23 ); cuticle with moderately dense, long, golden, decumbent pubescence; elytra bear a pair of dense, erect setal clusters near and slightly above midpoint of elytral suture. Head: Transverse, about 1.1X as broad as long, frons subdepressed; punctures on frons and vertex round and moderately deep, about 1.5X size of an eye facet, separated from each other by 0.5–1.0 puncture diameter; eyes moderately large and moderately projected, about 0.4X as long as head, outer margin rounded, somewhat finely facetted; temple indistinct; golden yellow setae present on frons and vertex. Antenna about 1.4X as long as head; antennal club about 1.3X as long as broad, club segments compact, about 0.3X as long as antenna. Pronotum: Transverse (LP:WP = l.0: 1.9), anterior margin broadly emarginate ( Fig. 2 ); lateral margins arcuate, posterior margin bisinuate, anterior angles sharply obtuse, posterior angles obtusely rounded with truncate apices, lateral margins bordered with a dense row of moderately long cilia, about 1/5 length of eye. Rather convex, surface distinctly punctate, punctures about as large as those on vertex, separated by 1–2 puncture diameters; moderately dense, decumbent setae on disc. Scutellum: Transverse, about 1.6X as broad as long, triangular with sides somewhat arcuate; punctures round, about half the size of eye facets, separated by 0.5–1.0 puncture diameter; setae very fine, short, sparse. Elytra: About 1.2X as broad as long, humeral angles nearly right-angled, sides moderately arcuate, borders somewhat explanate, apices separately rounded (Figs, 4. 7); punctures round, about the size of those on pronotum, separated by 1–2 puncture diameters; moderately dense, long, decumbent pubescence interspersed with somewhat short, fine, appressed setae. Abdominal tergites: Partially covered by elytra, exposed part of abdomen 3X as broad as long, pygidial apex medially emarginated. Venter: Uniformly reddish brown. Prosternal process subparallel with bulbous apex ( Fig. 24 ). Abdominal ventrite with hypopygidium extended as a short process from the midpoint of preceding abdominal ventrite. Aedeagus: Broadly elongate, membranous median lobe with subparallel sides and a single median strut ( Figs. 19–20 , 53–54 ); tegmen with paired leg-like parameres, tuft of long setae arising 1/4 distance from apices of parameres, tegminal struts arising from basal extremity of each paramere. In lateral view ( Fig. 53 ), hook-like parameres gradually narrowing from base to apex; apex distinctly pointed, tuft of setae arising from ventral margin.

Measurements. TL = 4.40–5.20 mm; WH = 0.79–0.80 mm; LA = 1.01–1.05 mm; LP = 1.39–1.46 mm; WP = 2.77–2.78 mm; LE = 2.49–2.55 mm; WE = 2.97–3.02 mm.

Etymology. Gender: Feminine. The species is named after Ms. Kabita Dasgupta, mother of the first author, for her immense support in the research work.

Distribution. INDIA: Arunachal Pradesh; Jharkhand.

Comparative Notes. This species resembles A. lobanovi in the shape of the last abdominal segment and hypopygidium and the shape of male genitalia. It can be differentiated by the distinctly pointed apex of the parameres with short and sparse setae in lateral view, narrow parameres rather separated from each other in dorsal view, and elytra rather convex laterally (vs. apex of parameres somewhat blunt with moderately long and dense tuft of setae in lateral view and parameres slightly stouter, rather close to each other in dorsal view; elytra less convex laterally in A. lobanovi ). The species is also similar to the Chinese species Amphicrossus triparcus Kirejtshuk, 2005 in the structure of male genitalia but can be differentiated from the latter by the medially indented apex of the last abdominal segment and distinctly protruding hypopygidium (vs. apex of last abdominal segment uniformly rounded and short hypopygidium in A. triparcus ).

Figures

Figs. 21–28. Amphicrossus species in Northeast India. 21–22) A. discolor, dorsal and ventral views, respectively; 23–24) A. kabitae, dorsal and ventral views, respectively; 25–26) A. brunneus, dorsal and ventral views, respectively; 27) A. adustipennis, dorsal view; 28) A. densatus, dorsal view (photograph by Andrew Cline).

Figs. 1–10. Amphicrossus kabitae. 1) Head, ventral view; 2) Prothorax, ventral view; 3) Meso-metathorax, ventral view; 4) Right elytron, dorsal view; 5) Abdomen, ventral view; 6) Wing; 7) Right elytron, lateral view; 8) Front leg; 9) Mid-leg; 10) Hind leg.

Figs. 11–20. Amphicrossus kabitae. 11) Mandible, dorsal view; 12) Maxilla, ventral view; 13) Labrum, dorsal view; 14) Labium, ventral view; 15) Scutellum, dorsal view; 16) Anal sclerite, ventral view; 17) Spiculum gastrale; 18) Metendosternite; 19) Male genitalia, dorsal view; 20) Male genitalia, lateral view.

Figs. 53–60. Amphicrossus species, male genitalia, lateral and ventral views, respectively. 53–54) A. kabitae;