Megarthrus nilgiriensis, Cuccodoro, Giulio & Liu, Zhiping, 2016

Cuccodoro, Giulio & Liu, Zhiping, 2016, Megarthrus of southern India and Sri Lanka, with notes on their phylogenetic and biogeographical relationships (Coleoptera: Staphylinidae: Proteininae), Zootaxa 4097 (4), pp. 530-544 : 537-539

Megarthrus nilgiriensis sp. nov.

( figs 5 , 31–47 )

Specimens examined. 15: Holotype, male: INDIA: Tamil Nadu: " India, Madras, Nilgiri, Ootacamund. 2150– 2200m, 21.xi.1972, leg. Besuchet, Löbl & Mussard, #41b+a [sifting leaf litter in remnant of primary forest and under bush in small ravine] (MHNG; accession number MHNG ENTO 00008937); Paratypes, 17: same data as holotype (MHNG, 5 males and 5 females); Nilgiri, Coonoor. 1600m, 22.xi.1972, leg. Besuchet, Löbl & Mussard, #43 [sifing in forest above town] (MHNG, 1 male and 1 female); Nilgiri, 7km. E. Coonoor. 1350m, 19.xi.1972, leg. Besuchet, Löbl & Mussard, #38 [sifing in forest] (MHNG, 2 males and 2 females); Nilgiri Hills, 5 km E Kundah, Vallakadavu, 78°40’E 11°18’N, 1900m, 23.i.1999, leg. Boukal, #80 (NHMW, 1 male and 1 female).

Description. Similar to M. narendrani , from which it differs as follows: Habitus as in fig. 5; combined length of head, pronotum and elytra = 1.65–1.85 mm; maximal pronotal width = 0.90–1.05 mm; body and appendages yellowish, except darker thoracic ventrites, and elytra each with broad blackish transverse subapical spot; antennae as in fig. 45; pronotum as in fig. 43.

Male. Anterior frontal margin conspicuously carinate, carina sinuate. Abdominal sternites IV–VI unmodified. Protarsomeres 1 lacking tenent setae. Mesofemora (fig. 39) about as long as metafemora. Mesotibiae (fig. 38) slightly longer than metatibiae. Metatarsomeres 1 shorter than metatarsomeres 2–4 combined. Peg-like setae arranged in a single row on mesotibiae; mesotrochanters (fig. 39) with 1–3 peg-like setae. Abdominal tergite VIII as in figs 36–37; sternite VIII as in fig. 35; hemitergites IX similar to that in fig. 55, with lateral lobe reduced. Aedeagus as in figs 31–34.

Female. Anterior frontal margin slightly carinate, evenly. Abdominal tergite VIII as in figs 46–47; sternite VIII as in fig. 44. Genital segment as in figs 40–42; gonocoxal plate without dorsal and ventral medial ridges.

Comparisons and diagnostic notes. See comparisons and diagnostic notes under M. bimaculatus and M. narendrani sp. n.

Distribution and natural history. The species is apparently restricted to the Nilgiri Hills, where it was collected mainly by sifting forest leaf litter at elevations ranging from 1350 to 2200 m a.s.l. Etymology. The species is named after the Nilgiri Hills, where it occurs.

Figures

FIGURES 1 – 5. Megarthrus, habitus, male; M. lanka sp. n. (1), holotype; M. rufomarginatus Cameron (2); M. bimaculatus Fauvel (3); M. narendrani sp. n. (4), holotype; M. nilgiriensis sp. n. (5), holotype. Scale bar = 0.5 mm.

FIGURES 31 – 39. Megarthrus nilgiriensis sp. n., male; aedeagus in ventral (31, 34) and lateral (32, 33) views; abdominal sternite VIII in ventral view (35); apex of abdominal tergite 8 in dorsal (36) and lateral (37) views; mesotibia (38); mesofemur and mesotrochanter (39). Scale bar = 0.1 mm.

FIGURES 40 – 47. Megarthrus nilgiriensis sp. n.; female genital segment, ventral part in dorsal (40) and lateral (41) views, and dorsal part (42) in ventral view; antenna (45); outline of pronotum (43); female abdominal sternite VIII in dorsal view (44); female abdominal tergite 8 in dorsal (46) and lateral (47) views. Scale bar = 0.1 mm.