Longizonitis Pan & Bologna

Pan, Zhao, Ren, Guodong & Bologna, Marco A., 2018, Longizonitis, a new nemognathine genus from the Himalayas (Coleoptera, Meloidae), ZooKeys 765, pp. 43-50 : 43

Longizonitis Pan & Bologna gen. n.

Type species.

Zonitis semirubra Pic, 1911 (originally described as Zonitis semiruber ) by present designation.

Etymology.

From the Latin adjective ‘longus’ and Zonitis . The name refers to the slender shape of body, which differs from that of several other nemognathine genera.

Diagnosis.

Longizonitis is clearly distinguishable from other nemognathine genera by the following characters: body elongate, length-width ratio distinctly more than 3.5; antennomere II distinctly shorter than III; elytra not reduced in size, only slightly dehiscent apically; tarsal claws with ventral blade narrow, its greatest width slightly more than half the basal width of dorsal blade; female with two metatibial spurs similar in shape and size, male external metatibial spur as in female, inner one stick-liked and only half width of external one; male ventrite VI completely divided, that of female V-emarginate; aedeagus without dorsal hooks, but with two sclerotised ventral lobes, curved posteriad; gonostyli almost completely fused, gonocoxal plate longer than gonostyli.

Description.

Head short, subrectangular, head width at temples slightly greater than at eyes, frons not depressed, surface with dense, large and shallow punctures (Fig. 4). Eyes normal in size, only extending ventrally to outer margin of maxillae on underside of head, slightly emarginate on fore margin near base of antenna. Mandibles robust and long, extending beyond fore margin of labrum; galeae short and fringed (as in fig. 71, Bologna and Pinto 2002); maxillary palpi four segmented, palpomeres not elongate, last palpomere not widening at apex. Antennae with eleven antennomeres, filiform, elongate and slender; antennae slightly longer than elytral length in male (Figs 1, 5), and shorter in female (Figs 2, 3); male antennomere II short, subglobose, about as wide as long, apical antennomeres equal in width to basal ones; female antennomeres distinctly shorter than in male, XI almost suboval (Figs 2, 3, 6).

Pronotum wider than long, punctures as on head, slightly more scattered (Fig. 7). Elytra elongate, normal, not reduced in size, slightly dehiscent apically on inner margin; each elytron with four weak costae and with dense short setae. Hind-wings present and regularly developed. Legs not modified in both sexes; both female metatibial spurs wide, spatulate and concave dorsally, similar and subequal in length and width; male external metatibial spur as in female, inner spur stick-liked and only half the width of external spur; tarsal claws with ventral blade narrow, its greatest width slightly more than half basal width of dorsal blade (as in fig. 100, Bologna and Pinto 2002); dorsal blade of claw with two rows of teeth along its ventral margin, outer row incomplete.

Male ventrite VI deeply cleft to base and completely divided longitudinally (as in fig. 105, Bologna and Pinto 2002); slightly V-emarginate in female. Male gonostyli almost completely fused, slightly separate at apex; gonocoxal plate longer than wide and longer than gonostyli, gibbous ventrally (Figs 8, 9). Aedeagus subcylindrical, without dorsal hooks, but with two sclerotised ventral lobes curved posteriorly; endophallus without hook (Figs 10, 11).

Distribution.

Southern China, northwestern India.

Relationships.

The new genus differs from all known Nemognathinae taxa and shows mixed distribution of character states; for this reason, their relationships remain difficult to define. It clearly belongs to the tribe Nemognathini and not to the Palaestrini Bologna, Turco & Pinto, 2013 or Horiini Latreille, 1802, due to the cylindrical shape of the aedeagus and unmodified mandibles (see Bologna et al. 2013). Among the tribe Nemognathini , the antennomere II distinctly shorter than III (typical of Palaestrini ) is an uncommon condition, present only in a few taxa, though notably occurring in the Afrotropical genus Zoltanzonitis (Bologna and Pinto, in press). The shortened antennomere II is also present in the Nemognatha -lineage as defined by Bologna et al. (2103) ( Palaestrida White, 1846, some Nearctic Nemognatha Illiger, 1807), in which, however, lack ventral sclerotized lobes of aedeagus.

Ventral sclerotised lobes are present in all New World Zonitis , Pseudozonitis Dillon, 1952 and Gnathium Kirby, 1818 species, and some Palaearctic species of Zonitis ; however, the short antennomere II is never represented in the American species.

In the new genus, galeae are neither penicillate nor greatly modified, a plesiomorphic condition more similar to that of Nemognathini of the sitarine lineage than that of typical lineage (see Bologna et al. 2008 for the lineages definition). Additionally, the shape of pronotum differs from that of most Nemognathini , except for some of the sitarine lineage.