Tegyrius radhikae, 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 : 352-354

TEGYRIUS RADHIKAE SP. NOV.

( FIGS 99–107 )

Distribution: India (Karnataka).

Host plant: Piper nigrum L.

Description: Entirely black, except for third antennomere, which is entirely brown; labrum, apex of first and second antennomeres, apex of metafemora, all tarsi, and metatibia with brown tint.

Supraorbital sulcus indistinct. Third antennomere shorter than fourth; fourth and fifth subequal, sixth shorter than fifth; seventh longer than sixth; eighth to tenth each apparently shorter than preceding one, last subequal to first; last four or five antennomeres gradually thickened; the antennae reach half of the elytra over the pronotum.

Pronotum with antebasal transverse impression, and with punctures in the antebasal transverse impression stronger than those on rest of pronotum. Apex of prosternal intercoxal process convex, with a pair of preapical depressions. Scutellum as broad as long, and with a narrowly rounded apex. Prosternal intercoxal process 6.2 times wider than the distance between the anterior margin of the prosternum and the coxal cavity; distance from anterior margin of the prosternum to the end of the intercoxal prosternal process 1.7 times the minimum width of the prosternal intercoxal process.

Mesosternum transversely depressed in the middle, with straight posterior margin. Elytra with maximum width at the middle; eltyral apex concave, and moderately broad; elytral punctures moderately strong, and forming uncountable rows, with the distance between adjacent punctures in the anterior half of the elytron 0.25–2.5 times the diameter of a single puncture. First metatarsomere half as long as the metatibia.

Subparallel ridges on first abdominal ventrite hardly reach the middle of the ventrite, and converge distally ( Fig. 99 ). Posterior margin of lobe in the middle of the last male ventrite convex ( Fig. 100 ). Last visible tergite of females with indistinct groove along the middle.

In lateral view, the aedeagus is gently curved, with an abruptly narrowed apex ( Fig. 102 ); the ventral side is convex, with a sharply raised, wedge-shaped, preapical ridge, and is widened near the distal twothirds, and the apex appears to be tridentate, with a preapical constriction in ventral view ( Fig. 101 ); distal opening partially closed by a pair of laminae ( Fig. 103 ); arms of tegmen much shorter than stem ( Fig. 104 ).

Spermathecal pump with horizontal part longer than vertical; receptacle about three times longer than wide, with the outer side concave near the middle, with the inner side convex near middle, and not narrowed towards the duct; duct twisted and coiled ( Fig. 105 ); vaginal palpus with lateral membranous area longer than proximal sclerotization; distal sclerotization about as long as lateral membranous area ( Fig. 106 ). Tignum with distal sclerotization oval shaped, and longer than wide ( Fig. 107 ).

Sexual dimorphism: First pro- and mesotarsomeres slightly enlarged in males compared with females. Mesotibia and first metatarsomere of males unmodified.

Measurements (n = 4): Length, 1.91–2.18 (2.07); width, 1.06–1.22 (1.13); length of pronotum, 0.49–0.53 (0.51); width of pronotum, 0.68–0.74 (0.72); width of head across eyes, 0.56–0.58 (0.57); transverse diameter of one eye, 0.20–0.22 (0.21); distance between eyes, 0.23–0.27 (0.26); distance between eye and antennal socket, 0.03–0.04 (0.03); distance between antennal sockets, 0.07–0.08 (0.07); diameter of one antennal socket, 0.07–0.08 (0.07); length of aedeagus, 0.90; length of receptacle, 0.25; length of vaginal palpus, 0.39.

Types: Holotype ♂. Labels: (1) India, Karnataka, Sakaleshpur , 10 January 2005, coll. N. S. Radhika from pepper; (2) Tegyrius radhikae sp. nov. Prathapan & Viraktamath, 2007; (3) Holotype ( BMNH) .

Paratypes (19 specimens): 8♂ and 7♀, with the same data as for the holotype ; 2♂ and 2♀, with the same data as the holotype, except that the date was 23 September 2004 (2 BMNH, 2 EUJ, 2 KUJ, 1 LMC, 2 NHMB, 2 NPC, 4 PKDC, 2 UASB, and 2 USNM) .

Etymology: This species is named after N. S. Radhika, who collected the types.

Remarks: Tegyrius radhikae sp. nov. can be separated from all other species of the genus based on the tridentate, and preapically narrowed, aedeagus. Tegyrius radhikae sp. nov. can be separated from T. keralaensis comb. nov., which looks similar, by the colour of the antennae (entirely yellow in T. keralaensis comb. nov., whereas it is black, except for the third antennomere, which is brown, in T. radhikae sp. nov.). In T. dalei sp. nov. and T. tippui sp. nov., the apex of the aedeagus appears tridentate in ventral view, but is preapically broadened, and not constricted as in T. radhikae sp. nov. This is a minor pest of black pepper in Karnataka.

Figures

Figures 99–104. Tegyrius radhikae sp. nov.: 99, intercoxal ridges on first abdominal ventrite; 100, male last abdominal ventrite; 101, aedeagus, ventral view; 102, aedeagus, lateral view; 103, distal opening; 104, tegmen.

Figures 105–107. Tegyrius radhikae sp. nov.: 105, spermatheca; 106, vaginal palpi; 107, tignum.