Perigona (Trechicus) timorensis, Baehr & Reid, 2017

Baehr, Martin & Reid, Chris A. M., 2017, On a Collection of Carabidae from Timor Leste, with Descriptions of Nine New Species (Insecta: Coleoptera, Carabidae), Records of the Australian Museum 69 (6), pp. 421-450 : 436-437

Perigona (Trechicus) timorensis sp. nov. Baehr

Figs 8 , 16

Holotype ♂, “ TIMOR LESTE gorge 1k NE Laclubar 8°44'47"S 125°54'54" E uro/siamweed above gorge, at mv light 1030m 3.vi.2012 C. Reid TL2012/107/598” K402525 ( AMS) . Paratypes (4): 2 ♂♂, 1♀, same data as holotYpe, K402521, K402524 (♂, ♀ AMS) , ♂ K402523 ( CBM) ; 1♂, “ TIMOR LESTE Mt Laritame. 8,69178S 126.38719E water tank, edge moss forest, 1150m TL2012/011/016 mv bucket trap 31.v.2012 ” K402522 ( AMS) .

Etymology. The name refers to the occurrence of this species on the island of Timor.

Diagnosis. A medium sized species with wide subapical channel, very wide aedeagus, and a pattern of various narrow, sclerotized rods in the internal sac ( Fig. 16); distinguished from most similarly shaped species by combination of wide prothorax with comparatively narrow base, and absence of regularly coiled structures in the internal sac. Further distinguished from the nearest related species P. punctatostriatus Baehr, 2013 and P. moluccensis Baehr, 2013 by pale latero-apical angles of the pronotum, longer elytra, the wide, pale margin of the elytra, greater number of deeplY impressed elYtral striae, and the different structure of the internal sac of the aedeagus.

Description. Measurements. Body length: 3.65–3.75 mm; width: 1.7–1.75 mm. Ratios. Width/length of pronotum: 1.43–1.48; width of widest diameter/base of pronotum: 1.21–1.24; width apex/base of pronotum: 0.93–0.95; width pronotum/head: 1.25–1.31; length/width of elytra: 1.37–1.40.

Colour ( Fig. 8 ). Black, apical angle of the pronotum widely pale yellow, also the lateral part of the elytra, about from 5th stria laterad, widely pale red. Clypeus and labrum, palpi, and antenna yellow to pale red. Femora pale yellow, tibiae and tarse slightly darker, pale red. Under surface more or less dark piceous, but lateral parts of thorax, and the whole abdomen paler, light brown to reddish-brown.

Head ( Fig. 8 ). Of average size, dorsal surface fairly depressed. Eye large, laterad markedly protruded; orbit very short. Labrum in middle slightly incised; mandibles elongate, straight; palpi elongate, maxillary palpus sparsely pilose. Mentum with acute, unidentate tooth and two elongate setae. Antenna short, median antennomeres slightly longer than wide. Posterior supraorbital seta situated at posterior margin of eye. Frons slightly convex, frontal furrows wide, fairlY deep, irregularlY curved. Surface with extremelY fine and sparse punctures which are only visible at very high magnification, with traces of verY superficial irregularlY transverse microreticulation, glossy.

Pronotum ( Fig. 8 ). Rather wide, widest slightly in front of middle, dorsal surface fairly depressed. Base rather wide. Apex well excised; apical angle protruded and widely rounded at tip; lateral margin gently convex, in basal third oblique and straight; basal angle obtusely rounded; base laterally slightly convex, in middle straight. Apex and middle of base not margined, lateral parts of base faintly margined. Lateral margin and channel anteriorly narrow, widened and explanate basad. Both transverse sulci shallow, median line distinct, slightly impressed, abbreviated on both ends. Anterior marginal seta situated at apical sixth, posterior marginal seta situated at basal angle. Extremely fine and sparse punctures barelY recognizable even at high magnification; surface in middle without microreticulation, in the apical, lateral, and basal parts with extremelY fine and superficial traces of microsculpture that is composed of transverse lines, very glossy.

Elytra ( Fig. 8 ). Rather short and wide, widest slightly behind middle, dorsal surface moderately depressed. Humerus wide, slightly produced but widely rounded, lateral margin slightly convex throughout, apex regularly convex, slightly incurved towards suture. Lateral margin rather narrow, behind humerus extremelY finelY denticulate and sparselY setulose; subapical sulcus rather wide.At least five, in some specimens also six, median striae deeply impressed and almost complete, rather coarsely punctate. The anterior discal puncture situated at basal third, the median puncture behind middle, the third puncture far removed from the apex. The subapical marginal sulcus with sparse and very short pilosity. Surface apparently impunctate, without microreticulation, very glossy, slightly iridescent.

Male genitalia ( Fig. 16). Genital ring moderately wide, almost parallel-sided, with wide, oblique, asymmetric apex and very narrow base. Aedeagus very compact, very wide in middle; lower surface gently bisinuate. Apex straight, short, wide, almost symmetric, triangular. Internal sac with several narrow, variously coiled sclerotized rods and folds. Both parameres large and comparatively elongate, with oblique-convex apex.

Female gonocoxites. Very similar to that of P. drumonti Baehr, 2013 as figured in fig. 66 in Baehr (2013): Gonocoxite 1 large, without any setae at the apical rim. Gonocoxite 2 triangularly curved, with slightly obtuse apex; with one elongate ensiform seta in middle of the ventro-lateral margin, a large ensiform set in middle of the dorso-median margin, and two attached nematiform setae originating from a groove in the apical third of the median margin.

Variation. Very little variation noted.

Distribution. Central part of Timor Leste.

Collecting circumstances. The species was sampled at light and in “bucket trap” in open Eucalyptus woodland with weeds, and at the edge of moss forest, both localities being slightly above 1000 m.

Remarks. This is the first species of Perigona explicitly recorded from Timor. However, apart from the widely distributed P. nigriceps (Dejean) which was also present in the examined material, other species are likely to occur on Timor, but have not yet detected as a consequence of the limited exploration of this island.

The new species in its external as well genitalic morphology is very similar to P. punctatostriata Baehr, 2013 from Sulawesi, less so to P. moluccensis Baehr, 2013 from the Moluccas. The close relationship to P. punctatostriata is best seen in the similarly shaped aedeagus and rather similarly structured internal sac. But also body shape, striation of the elytra, and surface structure are very similar, though the colouration is quite different. ApparentlY the new species forms a group with both mentioned species, which would suggest that it is a southern Oriental faunal element.

Perigona sp. — 1♀ ex. “Valu Sere Resort, opposite Jaco Is 8.40931S 127.29875E vine thicket on Is, 5mTL2012/004/019 mv bucket trap 26.v.2012 ”K402668 ( AMS). The specimen is quite similar to P. sumatrensis Baehr, 2013 , but for a reliable identification of these verY similarlY shaped and structured species the male genitalia are needed .

Figures

Figure 8. Perigona timorensis sp. nov. (body length 3.7 mm).