Pseudolathra tonsa, Assing, 2013

Assing, V., 2013, A revision of Pseudolathra of the East Palaearctic and Oriental regions. II. Six new species and additional records, with notes on some New World species, Linzer biologische Beiträge 45 (1), pp. 205-227 : 205-227

Pseudolathra tonsa nov.sp. (Figs 24-29, Map 5)

T y p e m a t e r i a l: Holotype 3: "Darjeeling Distr, India Bhakta B. / Kosi Khola, 9.XI.1980 / Holotypus 3 Pseudolathra tonsa sp. n., det. V. Assing 2013" (NHMB). Paratype 3: "O. Nepal, Bhakta B. / Chitra [recte: Chitre], 20.IX.1978 " (cAss).

E t y m o l o g y: The specific epithet (past participle of the Latin verb tondere: to shave) alludes to the absence of tufts of setae at the posterior margin of the male sternite VII, one of the characters distinguishing this species from the similar P. nigerrima .

D e s c r i p t i o n: Body length 7.7-9.5 mm; length of forebody 4.3-4.4 mm. Habitus as in Fig. 24. Coloration: head and pronotum black; elytra uniformly black or indistinctly paler anteriorly; abdomen black, with the extreme apex slightly paler; legs and antennae yellowish-red.

Head (Fig. 25) transverse, 1.15-1.20 times as broad as long, broadest across eyes; posterior angles moderately marked; dorsal surface impunctate, except for a few coarse punctures near dorsal margin of eye, on frons, and at posterior margin; microsculpture absent. Eyes large and bulging, distinctly more than twice as long as postocular region in dorsal view. Antennae approximately 2.8 mm long and slender.

Pronotum (Fig. 25) very weakly transverse, approximately 1.01-1.02 times as broad as long and about 1.1 times as broad as head; lateral margins subparallel in anterior half and converging in posterior half in dorsal view; posterior angles weakly marked; dorsal series composed of 1+5 coarse punctures; laterad of dorsal series with few coarse punctures on either side, plus additional punctures at lateral margin.

Elytra (Fig. 25) approximately 0.95 times as long as pronotum; humeral angles marked; dorsal surface with three series of punctures (one at suture, one along middle, and one laterally), each composed of 8-12 not very coarse punctures, between sutural and median series with an additional irregular series of very fine punctures. Hind wings fully developed. Metatarsomere I slightly shorter than II.

Abdomen narrower than elytra; punctation dense and coarse on tergite III, gradually becoming finer and sparser towards abdominal apex, very sparse and fine on tergite VII; interstices glossy, with fine, shallow, but noticeable transverse microsculpture; posterior margin of tergite VII with palisade fringe; posterior margin of tergite VIII strongly convex.

3: posterior margin of sternite VII broadly concave and without distinct tufts of black setae laterally (Fig. 26); sternite VIII with moderately narrow and deep posterior excision of nearly half the length of sternite (Fig. 27); aedeagus (Figs 28-29) 1.3 mm long; apex of ventral process of distinctive shape particularly in ventral view.

Figs 24-29: Pseudolathra tonsa nov.sp.: (24) habitus; (25) forebody; (26) male sternite VII; (27) male sternite VIII; (28-29) aedeagus in lateral and in ventral view. Scale bars: 24-25: 1.0 mm; 26- 29: 0.5 mm.

C o m p a r a t i v e n o t e s: The highly similar external and male sexual characters, particularly the similarly derived morphology of the aedeagus, suggest that P. tonsa is very closely related to, and probably the adelphotaxon of the sympatric P. nigerrima . It differs from this species by the paler coloration of the legs, by the different chaetotaxy of the male sternite VII (posterior margin without lateral tufts of black setae), and by the shape of the aedeagus, above all the shape of the apex of the ventral process.

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: Pseudolathra tonsa is currently known from two localities in the Himalaya, one in eastern Nepal and one in Darjeeling district, northern India (Map 5).