Bolboceras bilaspuricans Gupta & Chandra

Gupta, Devanshu & Chandra, Kailash, 2016, Bolboceras bilaspuricans (Coleoptera: Geotrupidae: Bolboceratinae), a new species from Chhattisgarh, India, Zootaxa 4103 (3), pp. 295-300 : 296-300

Bolboceras bilaspuricans Gupta & Chandra , new species

(Figs.2–12)

Type locality. India, Chhattisgarh State, Bilaspur District, Tilai Nala, Achanakmar-Amarkantak Biosphere Reserve, 22.624835ºN, 81.777361ºE.

Type material (2 specimens). Holotype, male: “ India: Tilai Nala, Achanakmar-Amarkantak Biosphere Reserve, Chhattisgarh state, Bilaspur district , 22.624835N, 81.777361E, 19.vii.2004, collected during day, coll. Ajeet Singh & Party ” (ZSI Registration Number: 21612/H4A ). Paratype, female: same locality data as holotype ( ZSI Registration Number: 21613/H4A) .

Type depository. Both type specimens are deposited in the collection of Zoological Survey of India, Kolkata, India.

Description (holotype, male). Body. Length 8.7 mm; width 3.0 mm. Shape subglobular. Colour uniformly dark brown and shiny. Head (Fig. 3). Labrum with slightly concave, anterior margin; apical ridge bisinuate. Lateral ridges of clypeus convergent to single, anteromedian, elevated point with apex rounded; perimarginal clypeal ridges distinct and K shaped. Clypeus sparsely punctate. Frons smooth with few punctures. Surface above and below interocular ridge smooth. Vertex densely punctate at base. Genal angle angulate. Anterior edge of eye canthus short with distinct anterolateral tubercle, arcuate at tip, surface rugopunctate. Paraocular ridge fine, virtually straight, posteriorly extending beyond side of interocular elevation. Transverse interocular elevation long, not reaching paraocular ridges. Pronotum (Fig. 4). Slightly depressed anteromedially (in lateral view), gradually sloping to steeper anterior declivity. Discoparamedian and lateral tubercles on pronotum slightly protuberant, weakly pointed. Discomedian impression and discolateral impressions shallow. Basomedian surface with distinct but fine, punctate midline impression; anterolateral angle of pronotum 90º. Pronotal surface with two types of punctures; larger punctures adundant laterally, anteriorly, and along margins and forming a cluster of 25 punctures from edge of lateral (punctate) fovea onto basomedian surface; minute punctures sparsely distributed. Pronotal base marginate. Scutellum (Fig. 7). Sparsely punctate. Elytra (Fig. 5). Discal striae weakly impressed, finely punctate. Intervals smooth. Legs. Protibiae with 6 distinct external denticles, denticles diminished in size from apex to base (Fig. 6), terminal spur sharp and slender. Mesotibiae and metatibiae with bilobate, apical elevation; 1 complete, anteapical, bilobate fossorial elevation; crest of elevations fringed with fine spines. Aedeagus ( Figs. 8– 10 ). Parameres subangular, aedeagal stalks with hooked tips. Lateral, sclerotized stalks broad at base and middle, slightly pointed and hooked at apex. Measurements (in mm). Median length of head (excluding labrum and mandibles) 1.7, maximum width 3.0; length of interocular elevation 0.9; ocular distance 1.7; median length of pronotum (dorsal) 3.9, maximum width 5.8; median length of scutellar plate 0.9, maximum width 1.0; sutural length of elytra (dorsal) 2.3, maximum width combined 5.8; width genital capsule 0.9.

Female (Paratype). Differs from male in perimarginal ridges of clypeus being trapeziform in shape.

Etymology. The name B. bilaspuricans refers to the Bilaspur district in the state of Chhattisgarh, India. Historical records explain that Bilaspur was named after a fisherwoman by the name of “Bilasa” in the 17th century.

Distribution ( Figs. 11–12 ). Only known from the type locality.

Differential diagnosis. Bolboceras bilaspuricans is characterized mainly by the unique structure of the aedeagus ( Figs. 8–10 ). The species in the B. nigricans group can be separated into two groups on the basis of perimarginal ridges of male clypeus being either K shaped or X shaped. The species with X shaped perimarginal ridges of clypeus are, Bolboceras extraneum Krikken, 2013 and B. insulare Krikken, 2013 . Whereas, the species with K shaped perimarginal ridges of clypeus are; B. mimicans Krikken, 2013 , B. nigricans Westwood, 1848 , B. schulzei Krikken, 2013 , and B. malabaricum Krikken, 2013 . In, B. mimicans and B. nigricans , the pronotal discomedian impression are deep whereas in B. schulzei and B. malabaricum , the pronotal discomedian impression are shallow or almost effaced. The new species, B. bilaspuricans , possess a K-shaped perimarginal ridges with the pronotal discomedian impression shallow. Structurally, B. bilaspuricans , resembles B. malabaricum and B. schulzei . In B. bilaspuricans , the paramere tip is subangular, the basal genitalic capsule of male not broad, the crest of interocular elevation not tuberculate, and the height of the interocular elevation on the frons is low; whereas in.

B. malabaricum , the parameral tip is acuminate, the basal genitalic capsule of male smaller, the crest of interocular elevation tuberculate (medially slightly raised), and the height of interocular elevation on the frons is high. Bolboceras bilaspuricans is also similar to B. schulzei , but the aedeagus has a different shape. In B. bilaspuricans , the aedeagal lateral stalks have hooked, recurved tips while in B. schulzei , the aedeagal stalks have slightly tapering tip that are not hooked. For details, see also the diagnostic character list for this species group ( Table 1).

Figures

FIGURES 8 – 12. Bolboceras bilaspuricans Gupta & Chandra, new species (holotype). (8) Entire aedeagus, upper side (entire), (9) Apical part of aedeagus (upper side), (10) Apical part of aedeagus (underside); (11) Map of India with Chhattisgarh state indicated; (12) Map of Chhattisgarh state with the type locality indicated.