Tegyrius metallicus, JACOBY, 1887

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 : 344-348

TEGYRIUS METALLICUS JACOBY

( FIGS 61–78 )

Tegyrius metallicus Jacoby 1887: 97–98 [type locality, Sri Lanka ; lectotype (BMNH), examined]. Maulik, 1926: 410, figs 134, 135. Heikertinger & Csiki, in Junk, 1940: 269. Scherer, 1969: 108.

Distribution: Sri Lanka . Host plant: Piper sp. near P. nigrum : this species very much resembles black pepper in habit, but the berries are larger and are not pungent in taste.

Description: General colour black. Antennae and legs light brown, with or without rufous tinge; metafemora, and often ventral side of metatibia, piceous. Elytra with indistinct green metallic reflection.

Supraorbital sulcus distinct. Third antennomere slightly shorter than fourth; fourth shorter or subequal to fifth; sixth shorter than fifth, and subequal to third; antennomeres 7–10 each slightly shorter than the preceding one; first subequal to last. Distal antennomeres not appreciably thickened; antennae reach half of the pronotum over the elytra or beyond.

Pronotum with antebasal transverse impression, and with punctures in the antebasal transverse impression not stronger than those on rest of the pronotum. Apex of intercoxal prosternal precess convex, with two preapical depressions. Prosternal intercoxal process 3.1 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 2.0 times the minimum width of the prosternal intercoxal process.

Mesoscutellum broader than long, with broadly rounded apex. Mesosternal intercoxal process transversely depressed in anterior half, posterior margin concave. Elytra with maximum width at middle; elytral apex concave, moderately broad; elytral punctures weak, and tend to form rows, with the distance between the adjacent punctures 1–3 times the diameter of a puncture in the anterior half of the elytra. First metatarsomere longer than half of the metatibia.

Subparallel ridges on the first abdominal ventrite well developed, with a row of setae, extending beyond two-thirds of the ventrite, and almost parallel to each other distally ( Fig. 70 ). Lobe in middle of last visible ventrite of males unique in being granulate, without long setae, and bearing longitudinal ridges on either side, with a concave apical margin ( Fig. 71 ). Last female tergite without a longitudinal groove.

Aedeagus distinctly curved in the middle, with straight ends in lateral view ( Fig. 73 ); in ventral view, apex broad, without angulate extremities, and with lateral edges distinctly raised, with a depressed area in between ( Fig. 72 ); distal opening partially covered by lamina ( Fig. 74 ); arms of tegmen slightly longer than stem ( Fig. 75 ).

Spermatheca with smoothly curved pump, receptacle about 2.5 times longer than broad, inner side convex, outer side concave, gradually narrowing towards duct, and with the duct highly knotted ( Fig. 76 ). Vaginal palpus with distal sclerotization longer than proximal sclerotization, and with proximal sclerotization subequal to the lateral membranous area ( Fig. 77 ). Tignum with broad distal sclerotization ( Fig. 78 ).

Sexual dimorphism: First pro- and mesotarsomeres slightly enlarged in males. Ventrally, first protarsomere with minute, bud-like sensilla in males, and with short, pointed setae in females. Ventromesal side of first metatarsomere with a shiny patch of short, capitate setae in males; in females, only pointed plumose setae present on ventral side of first metatarsomere.

Measurements (n = 4): Length, 2.26–2.62 (2.42); width, 1.28–1.51 (1.37); length of pronotum, 0.52–0.65 (0.57); width of pronotum, 0.78–0.94 (0.84); width of head across eyes, 0.59–0.68 (0.63); transverse diameter of one eye, 0.24–0.27 (0.26); distance between eyes, 0.27–0.30 (0.28); distance between eye and antennal socket, 0.02–0.04 (0.03); distance between antennal sockets, 0.07–0.09 (0.08); diameter of one antennal socket, 0.07–0.08 (0.08); length of aedeagus, 0.95; length of receptacle, 0.26; length of vaginal palpus, 0.42.

Type material examined: Lectotype ♀. Labels: (1) Ceylon, Lewis; (2) 1 st Jacoby coll.; (3) type 19043; (4)

Tegyrius metallicus Jac. ; (5) lectotype Tegyrius metallicus Jacoby des. K. D. Prathapan, 2007.

Other material examined: 4♂ and 5♀, Sri Lanka , Horton Plains National Park , 14 March 2006, coll. K. D. Prathapan ; 1♀, Nuwara Eliya , Hakgala, 12 March 2006, coll. K. D. Prathapan (1 BMNH, 1 EUJ, 1 KUJ, 1 NHMB, 1 NPC, 3 PKDC, 1 UASB, and 1 USNM) .

Remarks: Tegyrius metallicus resembles T. buddhai sp. nov. from Sri Lanka , and T. keralaensis comb. nov. from India, in both colour and other external features. Tegyrius buddhai sp. nov. can be differentiated easily from T. metallicus by the structure of the subparallel ridges on the first abdominal ventrite, and by the genitalia. Subparallel ridges converge and completely fuse distally in T. buddhai sp. nov. (whereas the ridges are nearly parallel in T. metallicus ). The aedeagus in ventral view in T. buddhai sp. nov. lacks ridges along the lateral margins (the lateral margins are raised, forming distinct ridges in T. metallicus ), and the outer side of the spermathecal receptacle is convex (concave in T. metallicus ). The antebasal transverse impression on the pronotum is indistinct in the middle in T. buddhai sp. nov. (but is stronger in the middle in T. metallicus ). Tegyrius metallicus can be separated from T. keralaensis comb. nov. by the structure of the aedeagus, the spermatheca, and the male last abdominal ventrite.

Figures

Figures 61–64. Tegyrius metallicus: 61, labrum; 62, maxilla; 63, mandible; 64, labium.

Figures 65–68. Tegyrius metallicus: 65, prosternum; 66, meso- and metasternum, and pleurites; 67, mesendosternite; 68, metendosternite.

Figures 69–75. Tegyrius metallicus: 69, metanotum; 70, intercoxal ridges on first abdominal ventrite; 71, male last abdominal ventrite; 72, aedeagus, ventral view; 73, aedeagus, lateral view; 74, distal opening; 75, tegmen.

Figures 76–78. Tegyrius metallicus: 76, spermatheca; 77, vaginal palpi; 78, tignum.