Bolboceras trimbakense Kalawate & Hillert, 2021

Kalawate, Aparna Sureshchandra & Hillert, Oliver, 2021, Two new species of the genus Bolboceras Kirby, 1819 (Coleoptera: Bolboceratidae Bolboceratinae) from India with an updated identification key of the Bolboceras nigricans Westwood, 1848 species group, Zootaxa 4964 (3), pp. 559-570 : 565-566

Bolboceras trimbakense Kalawate & Hillert , new species

( Table 1 , Figs. 2A–E , 3H , 5 )

Type locality. Trimbakeshwar , Nashik District, Maharashtra, India (19.984N, 73.518E, 696 m a.s.l.) .

Type material. Holotype, male, (collection of B.S. Lamba, ZSI-WRC, ENT-1/3535). “Trimbakeshwar, Nashik district , Maharashtra, India (19.984N, 73.518E, altitude 696 m), 15 October 1965 ”.

Description of holotype, male ( Fig. 2E ). Body convex, subglobular, dark brown and relatively shiny.

Head ( Figs. 2A , 4H ). Labrum with slightly concave anterior margin; transverse ridge distinctly thin, concealed in large punctures; lateral perimarginal ridge of clypeus convergent to single, anteromedian, distinctly raised tubercle, with nearly rounded apex. Anterior edge of eye canthus comparatively long, straight, surface rugo-punctate, with blunt and small anterolateral tubercle; perimarginal clypeal ridge distinct, k-shaped; frons with few scattered punctures; vertex sparsely punctate; transversal interocular ridge strongly developed, slightly curved in middle, interocular elevation very high, long, reaching to paraocular lines; paraocular line fine, almost straight, reaching beyond level of the interocular elevation, but not reaching base of head.

Pronotum ( Fig. 2B ). Prominently depressed anteromedially in lateral view; prominent conical discoparamedian protrusions present, apex rounded, anterior declivity steep; discolateral protrusions relatively elevated; discomedian impression deep; discolateral impressions very deep; margins of discolateral and discomedian impressions covered with minute punctures; midline minutely punctate; Pronotum finely punctate, punctation mostly present in the anterior region, sparse punctation present in basal region; basal margin punctate.

Scutellum ( Fig. 2D ). Finely, closely punctate.

Elytra. Relatively strongly impressed, with finely punctate striae; intervals smooth.

Legs. Protibiae with 6 distinct denticles, size descending basad; terminal spur robust, thick, tapering. Mesotibiae and metatibiae with two sharp spurs.

Aedeagus ( Fig. 2C ). Parameres leaf like acuminate, short, not reaching paramedian aedeagal struts, apex point- ed; lateral sclerotized aedeagal stalks thick, robust, strongly recurved; paramedian aedeagal struts globular, median aedeagal apparatus globular at apex; basal piece slender.

Differential diagnosis. The new described species is closely related to B. nigricans . Both species are characterized by a tubercle at the front edge of clypeus, the perimarginal ridges of clypeus are distinctly k-shaped and the interocular ridge is distinct long and situated approximately at the middle of eyes. The new species can be distinguished by the straighter interocular ridge, which is situated at the frontal third of eyes level and the less developed tubercle of genae. Furthermore, differences of the aedeagus distinct, in particular the characteristics of the lateral sclerotized aedeagal stalk ( Fig. 2C ). Other closely related species are B. sahyadriense Kalawate & Hillert, 2018 and B. bopdevense Kalawate & Hillert , new species described above. The new species can be distinguished from those two species by the position of the interocular ridge, the shape of genae and the aedeagus ( Fig. 2C ).

Measurements. Body length: 12.39 mm, width: 7.76 mm. Head, length in dorsal view excluding labrum and mandibles: 2.52 mm, width: 4.24 mm; interocular ridge: 2.34 mm; ocular distance: 2.81 mm. Pronotum length: 5.37 mm, width: 8.56 mm. Scutellar shield length: 1.17 mm, width: 1.33 mm. Elytra, sutural length: 4.83 mm. Genital capsule length: 4.22; maximum width 1.71 mm.

Female. Unknown.

Etymology. The species is named after the type locality, Trimbakeshwar of the Nashik district, Maharashtra.

Distribution. Known only from Nashik district of northern Western Ghats of Maharashtra, India.

Figures

FIGURE 2. Holotype of Bolboceras trimbakense Kalawate & Hillert new species. A, head in dorsal view; B, pronotum in dorsal view; C, aedeagus dorsal (left), lateral (middle), ventral (right); D, scutellum; E, dorsal habitus, not to scale.

FIGURE 3. Head and anterior angles of pronotum of Bolboceras species of the B. nigricans Westwood, 1848 species group with characteristic of x-shaped perimarginal ridges of clypeus, schematically, made on the basis of the images of the holotypes provided in the original descriptions. A, B. darjeelicans Gupta & Chandra, 2016; B, B. extraneum Krikken, 2013; C, B. insulare Krikken, 2013; D, B. schulzei Krikken, 2013; not to scale.

FIGURE 4. Head and anterior angles of pronotum of Bolboceras species of the B. nigricans Westwood, 1848 species-group with characteristic of k-shaped perimarginal ridges of clypeus, schematically, A–E, G–H made on the basis of the images of the holotypes provided in the original descriptions; F locality Coimbatore. A, B. arunachalense Gupta, Chandra, Ghosh, & Das, 2020; B, B. bilaspuricans Gupta & Chandra, 2016; C, B. bopdevense Kalawate & Hillert new species; D, B. malabaricum Krikken, 2013; E, B. mimicans Krikken, 2013; F, B. nigricans Westwood, 1848; G, B. sahyadriense Kalawate & Hillert, 2018; H, B. trimbakense Kalawate & Hillert, new species; not to scale.

FIGURE 5. Distribution map of the Bolboceras nigricans Westwood, 1848 species group in the Oriental and east Palearctic regions. Circles represents the type localities, squares the additional known localities of this group; – B. arunachalense Gupta, Chandra, Ghosh, & Das, 2020; – B. bilaspuricans Gupta & Chandra, 2016; – B. bopdevense Kalawate & Hillert, new species; – B. darjeelicans Gupta & Chandra, 2016; – B. extraneum Krikken, 2013; – B. insulare Krikken, 2013; – B. malabaricum Krikken, 2013; – B. mimicans Krikken, 2013; – B. nigricans Westwood, 1848; – B. sahyadriense Kalawate & Hillert, 2018; – B. schulzei Krikken, 2013; – B. trimbakense Kalawate & Hillert, new species.