Amphicrossus discolor Erichson 1843
Creators: name: Dasgupta, Jhikmik
name: Pal, Tarun Kumar
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Nitidulidae
Amphicrossus
Amphicrossus discolor

description: 4. <i>Amphicrossus discolor</i> Erichson, 1843 <i>Amphicrossus discolor</i> Erichson 1843: 348. <b>Material Examined.</b> INDIA: Arunachal Pradesh, Namdapha Tiger Reserve, 27.4455° N, 96.5358° E, 08.iv.1981, S. Biswas, 1 ex.; Uttarakhand, Dehradun, base of W. Himalaya, 30.3165° N, 78.0322° E, viii.1910, V. S. Iyer, Det. by Grouvelle as <i>Amphicrossus opacus</i> (Reg. No. 8607/ 18, 8608/18, 8611/18), 3 ex.; Bengal, Madhupur (presently Jharkhand state), 22.6302° N, 87.0562° E, 18.x.1909, C. Paiva, Det. by Grouvelle as <i>Amphicrossus oblongus</i> Grouvelle (Reg. No. 3497/ 21) 1 ex.; Bengal, Rajmahal (presently Jharkhand state), 25.0543° N, 87.8309° E, 06.vii.1909, Annandale, <i>ex</i>: rotten patch on living tree trunk, Det. by Grouvelle as <i>A. discolor</i> (Reg. No. 1289/16) 2 ex. <b>Description.</b> Oval, globose, ventrally subdepressed, color chestnut-brown to dark brown, finely punctate dorsum (Fig. 21); cuticle with moderately dense, long, golden, decumbent pubescence; elytra bearing a paired brush of dense, erect setal clusters near and slightly above the midpoint of the elytral suture. <b>Head:</b> Transverse, about 1.2X as broad as long, frons subdepressed; punctures on frons and vertex round and moderately deep, about size of an eye facet, separated by 1–2 puncture diameters; eyes moderately large and moderately projected, about 0.4X as long as head, outer margin rounded, 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. <b>Pronotum:</b> Transverse (LP:WP = l.0: 1.6), anterior margin broadly emarginated; lateral margins arcuate, posterior margin bisinuate, anterior angles sharply obtuse, posterior angles broadly rounded, lateral margins bordered with a dense row of moderately long cilia about 1/4 as long as eye. Rather convex (Fig. 29), surface distinctly punctate, punctures about as large as those on vertex of head, separated by 1–2 puncture diameters; moderately thick and dense, decumbent setae on disc. <b>Scutellum:</b> Transverse, triangular with sides somewhat arcuate; punctures round, about half size of an eye facet, separated by 2–3 puncture diameters; setae indistinct. <b>Elytra:</b> About 1.2X as broad as long, anterior margin closely fit with posterior margin of prothorax, humeral angles nearly right-angled, sides slightly arcuate, borders somewhat explanate, apices separately rounded (Figs. 32, 35); punctures round, about size of an eye facet, separated by 1–2 puncture diameters; setae fine and moderately long, decumbent. <b>Abdominal tergites:</b> Partially covered by elytra, exposed part of abdomen about 1.9X as broad as long. Pygidium (Fig. 38) with rounded apex, short setae present on apical margin. <b>Venter:</b> Uniformly reddish brown (Fig. 22). Prosternal process subparallel with apex rounded, reaching to mesoventrite. Metaventrite punctate-pubescent. Abdominal ventrite (Fig. 41) with hypopygidium flat and accommodated within the sinuated margin of the preceding abdominal segment. <b>Aedeagus:</b> Broadly elongate, membranous median lobe with subparallel sides and a single median strut; 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 parameres (Figs. 50, 59–60). In lateral view (Figs. 47, 59), hook-like parameres gradually narrowing from base to apex, parameres distinctly sinuate near midpoint of dorsal surface, apex somewhat projected laterally, a tuft of setae arising from ventral margin of parameres. <b>Measurements.</b> TL = 4.58–4.73 mm; WH = 0.78–0.79 mm; LA= 0.95–1.03 mm; LP = 1.49– 1.58 mm; WP = 2.53–2.61 mm; LE = 2.20–2.56 mm; WE = 2.68–2.84 mm. <b>Distribution. INDIA:</b> Arunachal Pradesh [New State Record], Assam, Sikkim, Uttarakhand, Jharkhand [New State Record]; <b>MYANMAR:</b> Pegu; <b>VIETNAM</b>; <b>TAIWAN</b>; <b>CHINA</b>. <b>Remarks.</b> The identity of this species was ascertained from a line drawing of the male genitalia of <i>A. discolor</i> sent by Dr. A. G. Kirejtshuk, Russian Academy of Sciences, St. Petersburg. The two specimens in the ZSI collection that were determined by A. Grouvelle as <i>A. opacus</i> and <i>A. oblongus</i> are conspecific, and their male genitalia conform with that of <i>A. discolor</i> (drawn by A. G. Kirejtshuk). Hence, the specimens are now redetermined as <i>A. discolor</i>.
description: Published as part of <i>Dasgupta, Jhikmik &amp; 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, pp. 307-320 in The Coleopterists Bulletin 73 (2)</i> on page 318, DOI: 10.1649/0010-065X-73.2.307, http://zenodo.org/record/5371621
description: {"references": ["Erichson, W. F. 1843. Versucheiner systematischen Eintheilung der Nitidularien. Germar Zeitschrift fur die Entomologie 4: 225 - 361."]}