Tegyrius pucetibialis, Prathapan & Viraktamath, 2009

Prathapan, K. D. & Viraktamath, C. A., 2009, Revision of Tegyrius (Coleoptera: Chrysomelidae: Galerucinae: Alticini), with descriptions of eight new species, Zoological Journal of the Linnean Society 157 (2), pp. 326-358 : 350-351

TEGYRIUS PUCETIBIALIS SP. NOV.

( FIGS 90–98 )

Distribution: India (Tamil Nadu).

Host plant: Piper mullesua Buch. - Ham.

Description: Entirely chestnut brown; head, pronotum, and all sternites apparently darker than the elytra.

Supraorbital sulcus distinct. Third antennomere shorter than fourth; fifth subequal to or slightly longer than fourth; sixth shorter than fifth; seventh subequal to fifth; eighth to ninth each slightly shorter than preceding one; tenth subequal to or shorter than ninth; last subequal to first; distal three to four antennomeres thickened or not; the antennae extend well beyond half of the elytra over the pronotum.

Pronotum with antebasal transverse impression, and with punctures in the antebasal transverse impression stronger than those on the rest of the pronotum. Apex of prosternal intercoxal process convex, with preapical depressions. Prosternal intercoxal process 1.4 times wider than the distance between the anterior margin of the prosternum and the coxal cavity; distance from the anterior margin of the prosternum to the end of the intercoxal prosternal process 3.3 times the minimum width of the prosternal intercoxal process.

Scutellum as broad as long, apex acute. Mesosternum depressed on top, with concave posterior margin. Elytra with maximum width at posterior two-fifths. Elytral apex convex, and broad. Elytral punctures do not form rows, and are moderately strong, with the distance between adjacent punctures 1–3 times the diameter of a puncture in the anterior half of the elytron. First metatarsomere distinctly longer than half of the metatibia.

Subparallel ridges on the first abdominal ventrite do not reach the middle of the ventrite, and converge distally ( Fig. 90 ). Last visible tergite of females with a shallow groove. Lobe in the middle of the posterior margin of the last male ventrite with convex posterior margin ( Fig. 91 ).

Aedeagus gently curved in lateral view, with acute apex ( Fig. 93 ); in ventral view, ventral surface convex, with a transparent window, apex obtuse, with a tiny denticle in the middle ( Fig. 92 ); distal opening partially covered with lamina ( Fig. 94 ). Arms of tegmen shorter than stem ( Fig. 95 ).

Spermatheca with horizontal part of pump longer than vertical part, receptacle about three times longer than wide, outer side convex, inner side indistinctly concave in middle, not narrowing towards duct; duct twisted several times ( Fig. 96 ). Vaginal palpus distinctly narrowed at distal two-thirds; lateral unsclerotized area shorter than distal or proximal sclerotization; proximal sclerotization longer than distal sclerotization ( Fig. 97 ). Distal sclerotization of tignum longer than wide ( Fig. 98 ).

Sexual dimorphism: First pro- and mesotarsomeres slightly enlarged in males compared with females. Mesotibia in lateral view distinctly curved and distally enlarged in males, slightly curved and distally not enlarged in females. First metatarsomere of male unmodified.

Measurements (n = 4): Length, 2.30–2.64 (2.55); width, 1.15–1.37 (1.29); length of pronotum, 0.54–0.57 (0.55); width of pronotum, 0.75–0.84 (0.81); width of head across eyes, 0.58–0.63 (0.61); transverse diameter of one eye, 0.21–0.24 (0.23); distance between eyes, 0.26–0.27 (0.26); distance between eye and antennal socket, 0.02–0.03 (0.03); distance between antennal sockets, 0.08–0.09 (0.09); diameter of one antennal socket, 0.07–0.08 (0.08); length of aedeagus, 1.10; length of receptacle, 0.30; length of vaginal palpus, 0.49.

Types: Holotype ♂. Labels: (1) South India, Western Ghats , Tamil Nadu, Avalanchi , 2030 m a.s.l., 25 June 2004 11°18′0.003″N, 76°35′42.8″E, coll. K. D. Prathapan; (2) Tegyrius pucetibialis sp. nov. Prathapan & Viraktamath, 2007; (3) Holotype ( BMNH) .

Paratypes (53 specimens): 21♂ and 24♀, with the same data as for the holotype ; 3♂ and 3♀, with the same data as for the holotype, except that the date was 26 June 2004 ; 1♂, India, Tamil Nadu, Avalanchi , 21 October 2003, coll. K. D. Prathapan ; 1♀, with the same data except for the locality, Emerald-Avalanchi , and the date, 22 October 2003 (10 BMNH, 2 EUJ, 2 KUJ, 2 LMC, 10 NHMB, 10 NPC, 5 PKDC, 2 UASB, and 10 USNM).

Etymology: Puce means ‘flea’ (coloured) in French. The name refers to the brown colour of the beetle, and the modified mesotibia.

Remarks: Tegyrius pucetibialis sp. nov. is confined to the upper reaches of the Nilgiri mountains. It can be separated from the closely related T. nigrotibialis sp. nov. by colour, and by the structure of the aedeagus. The general colour of T. pucetibialis sp. nov. is brown, whereas that of T. nigrotibialis sp. nov. is black. The apex of the aedeagus in ventral view is unidentate in T. pucetibialis sp. nov., whereas it is bifid in T. nigrotibialis sp. nov. Although both of them share the same host plant, they are not sympatric, as T. nigrotibialis sp. nov. is confined to the lower reaches of the Nilgiri Hills. Tegyrius pucetibialis sp. nov. closely resembles T. nigrotibialis sp. nov. in having sexually dimorphic mesotibia, a broad elytral apex, the same host plant, and a narrow and close, but parapatric, range of distribution. The two species can be separated from the other species of Tegyrius based on the sexually dimorphic mesotibiae and the structure of the aedeagus, besides the broad elytral apex.

Figures

Figures 90–98. Tegyrius pucetibialis sp. nov.: 90, intercoxal ridges on first abdominal ventrite; 91, male last abdominal ventrite; 92, aedeagus, ventral view; 93, aedeagus, lateral view; 94, distal opening; 95, tegmen; 96, spermatheca; 97, vaginal palpi; 98, tignum.