Notagonum angusticolle, 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 : 434-435

Notagonum angusticolle sp. nov. Baehr

Figs 6 , 7 , 15

Holotype ♂, “ TIMOR LESTE 7 k E Laclubar on Manatuto Rd 8°44'39"S 125°58'29"E grassy bog/stunted E uro [phylla]/ Melastoma 1180m 4.vi.2012 C. Reid TL2012/108/600” K402608 ( AMS) . Paratype: 1 ♂, “ TIMOR LESTE 2.7 k N Aileu 8°47'28"S 125°33'46"E coffee/ Paraserianthes 950m 1.vi.2012 C.Reid TL2012/101/587 sweeping” K402616 ( CBM) .

Etymology. The name refers to the narrow pronotum.

Diagnosis. A medium sized, reddish-piceous species, distinguished from both other species recorded from Timor by the narrow, barely punctate prothorax, the distinct denticle at the apex of the elytra, and a distinct angle at the apex of the 3rd stria; further distinguished from N. pleurale ( Jordan, 1894) , by slightly lesser body size, impunctate thoracic and abdominal sterna, and almost similarly sized lobes of the 4th tarsomere of the metatarsus; and from N. reidi sp. nov. bY longer elYtra, slenderer antenna, and different structure of the internal sac of the aedeagus.

Description. Measurements. Body length: 7.75–7.8 mm; width: 2.95–3.0 mm; ratios: width/length of pronotum: 1.19– 1.21; width widest diameter/base of pronotum: 1.17–1.19; width base/apex of pronotum: 1.38–1.39; width pronotum/ head: 1.31; length/width of elytra: 1.68–1.72; length/width of 6th antennomere: 3.8–3.9.

Colour ( Fig. 6 ). More or less dark piceous, lateral margins of the pronotum conspicuously and rather widely pale red, margin of elytra not perceptibly paler. Labrum, mandibles, and palpi piceous, antenna piceous, but three basal antennomeres slightly paler than the rest. Frons with two large though indistinct, more or less dark red spots. Legs dark red to piceous, outer surface of the tibiae slightly darker. Epipleura of prothorax and elytra more or less pale red, lower surface reddish-brown.

Head ( Fig. 6 ). Of average size, dorsal surface moderately convex. Eye large, laterad moderately protruded; orbit short, oblique, slightly less than one third of length of eye. Labrum anteriorly straight; mandibles of normal size and shape; palpi elongate, impilose. Mentum with acute, unidentate tooth and two elongate setae. Submentum quadrisetose. Antenna very elongate, median antennomeres almost 4 × as long as wide, densely pilose from middle of 4th antennomere. Frons regularly convex, frontal furrows linear, rather shallow, slightly outturned. Neck with shallow but distinct transverse sulcus. Surface glabrous, without microreticulation except on labrum, without perceptible punctures.

Pronotum ( Fig. 6 ). Comparably narrow, widest at or slightly in front of middle, dorsal surface gently convex. Base rather wide, wider than apex. Apex well excised; apical angle protruded and widely rounded at tip; lateral margin gently convex to base, near base not sinuate. Base in middle straight, laterally rather oblique. Basal angle obtuse, at tip even shortly rounded, c. 110°. Apex and base completely margined. Lateral margin and channel in apical half narrow, but deep, basad widened and explanate. The anterior transverse sulcus rather shallow, narrow, the posterior sulcus deeper; median line distinct, well impressed, almost complete. The anterior marginal seta situated slightly in front of middle, the posterior seta situated very slightly in front of the basal angle. Disk irregularlY transverse, with verY superficial strioles. Lateral margin and base barely punctate. Disk without perceptible microreticulation and apparently impunctate, surface very glossy.

Elytra ( Fig. 7 ). Rather elongate, slightly widened apicad, widest slightly behind middle, dorsal surface moderately depressed. Humerus wide, slightly produced but widely rounded, lateral margin in basal half almost straight but slightly oblique, in apical half regularly convex, with rather shallow, not angulate excision near apex; at level of 3rd stria with an obtuse but distinct, angle, and with a short, distinct sutural denticle. Lateral margin very narrow. Striation complete and well impressed, all striae extended to apex, impunctate. Intervals depressed. The anterior discal puncture situated at basal fourth and attached to the 3rd stria, the median puncture situated about at apical third, the third puncture about at apical sixth, both, median and posterior punctures attached to the 2nd stria. Setae fairly elongate. Marginal series consists of 18 punctures that less dense in middle. Surface with extremelY fine traces of verY transverse microreticulation, very glossy, slightly iridescent.

Lower surface. Surface, including abdomen, impilose and almost impunctate, except the narrow mesepisternum which is punctate. Surface glossy throughout. Metepisternum elongate, slightly> twice as long as wide at apex . Terminal sternum in male bisetose.

Legs. Of normal shape and structure. Tarsi sulcate on both sides. 4th tarsomere of metatarsus little excised, the outer lobe little longer than the inner one. 1st–3rd tarsomeres of the male protarsus widened and biseriately squamose.

Male genitalia ( Fig. 15 ). Genital ring rather narrow, almost parallel-sided, with asymmetric, obtusely triangular apex and very narrow base. Aedeagus rather narrow and elongate, straight, depressed, lower surface, apart from near base, almost straight. Apex rather elongate, straight, depressed, obtusely triangular. Folding of internal sac rather simple, but in middle of bottom with a short, sclerotized piece and another, curved, narrow, sclerotized rod. Both parameres comparatively short and compact, the right stouter, both with obtusely triangular apex.

Female gonocoxites. Unknown.

Variation. Very little variation noted,

Distribution. Upland areas in western part of Timor Leste.

Collecting circumstances. One specimen was collected at 1180 m in a grassy bog beside stunted eucalypt woodland with grass and Melastoma , the other was collected at 950 m in a plantation of coffee shaded bY Paraserianthes , by sweeping.

Remarks. In body shape and colouration both new species are quite similar to the other described Timorese species, N.

pleurale. However, both differ in some respects from that species: e.g. in body size and little or not punctate thoracal and abdominal sterna. With respect to the wide and laterally punctate pronotum and the almost unarmed apex of the elytra, N. reidi comes closer to N. pleurale , whereas N. angusticolle is more distinct, mainly in view of the distinctly denticulate elytral apex. Comparison of both new species with almost all described, similarly sized and structured species of the genus from New Guinea andAustralia corroborates their taxonomic distinctness. The same applies for those species of Notagonum that are recorded from neighboring areas, e.g. Sulawesi, the southern Lesser Sunda Islands, and the Moluccas.

Presumably the genus Notagonum is a Papuan, or even an Australian, faunal element, because the few species that occur in Australia lack any special character states that are present in a couple of species in New Guinea: e.g. angulate or spined elytral apex, very narrow body shape, pilose abdominal sterna, small, but laterad markedly protruded eyes, and others. Although in Australia and in large parts of New Guinea Notagonum species are lowland dwellers, and many species are widely distributed, the high taxonomic and morphological diversity of the genus in New Guinea may be caused by the remarkably dissected surface of the central part of New Guinea with its very high mountains and deep valleys. Such a landscape strongly supports rapid speciation events.

The species of Notagonum on Timor belong to the Papuan-Australian fauna and thus show the close relation of part of the Carabid fauna of Timor to the Australian and Papuan fauna.

Figures

Figure 6. Notagonum angusticolle sp. nov., head and prothorax.

Figure 7. Notagonum angusticolle sp. nov., apex of the elytra.

Figure 15.Notagonum angusticolle sp.nov.male genitalia:aedeagus left side, parameres, genital ring. Scales 0.5 mm.