Indocarterus, Kаtаev & Wrаse, 2018

Kаtаev, Boris M. & Wrаse, Dаvid W., 2018, Notes on Ditomina, with description of two new genera and a new species (Coleoptera, Carabidae) from the Middle East and India, Zootaxa 4459 (2), pp. 350-368 : 354-355

Indocarterus gen. n.

Type species Indocarterus inexspectatus sp. n.

Diagnosis. Most similar in combination of characters (see key) to the genus Eocarterus Stichel, 1923 , but distinguished by having head relatively wider, mentum without median tooth, labrum more deeply concave anteriorly, pronotum not cordate, its sides largely rounded, with very short and shallow sinuation just before basal angles. From the species of subgenus Baeticocarus Jeanne, 1971, the member of the new genus additionally differs in complete basal elytral border ( Eocarterus s. str. has incomplete basal border as in Indocarterus gen. n.).

Description. Dorsum ( Figs 5, 6 ) and venter rather densely punctate and setose.

Head large, slightly narrower than pronotum, constricted behind eyes, with only one long seta near inner margin of eyes on each side. Lateral margin of frons ( Fig. 7 ) above insertion of antennae angularly rounded anteriorly. Labrum deeply concave anteriorly. Clypeus along anterior margin without convex smooth bead, rather deeply arcuately emarginate, and membranous base of labrum exposed. Genae wide. Mentum ( Fig. 10 ) without median tooth, separated from submentum by complete transverse suture. Ligular sclerite not widened at apex, without ventral plate, and with several rather long, visible in ventral view, dorsal setae in addition to two ventral distal setae. Paraglossae rather narrow, glabrous at margins. Terminal maxillary and labial palpomeres more or less cylindrical, narrowed distally.

Pronotum ( Fig. 8 ) not cordate, its sides not serrate, largely rounded, with very short and shallow prebasal sinuation sharply delimited anteriorly (see remarks).

Mesothorax and extreme base of elytra narrowed forming a very short neck-like constriction with scutellum above. Elytra not serrate at sides, basal border complete, strongly bent and raised near scutellum.

Three penultimate abdominal sternites, in addition to short and dense pubescence, only with two obligatory long setae along posterior margin.

Metacoxa without posteromedial setigerous pore. Profemur not denticulate along inner margin. Metatrochanter short, about a third as long as metafemur, rounded at apex. Protibia without long, finger-like acute apical process, with three or four preapical spines on outer margin, densely setose on ventral surface. Tarsi densely setose dorsally. Protarsus and mesotarsus of male not dilated and without ventral adhesive vestiture. Protarsomeres 1, 2 and 3 (sometimes also 4) each of both sexes with a short acute spine in middle of ventro-apical margin ( Fig. 9 ). Metatarsomere 1 scarcely shorter than 2+3.

Etymology. The genus name is a combination of the name of the country India and the name of the carabid genus Carterus .

Composition and distribution. The genus includes only one species, I. inexspectatus sp. n., from western India ( Fig. 24 ).

Remarks. It is possible that the short and shallow prebasal sinuation of pronotal sides ( Fig. 8 ) is actually a lateral part of pronotal base as in the members of the subgenus Philochtus Stephens, 1825 (genus Bembidion Latreille, 1802 ). In this case the pronotal sides of Indocarterus gen. n. are rounded to basal angles, but the base inside them is sinuate and the basal pronotal angles are correspondingly shifted from the base anteriad.

Figures

FIGURE 24. Geographical range of the subtribe Ditomina.

FIGURES 5, 6. Indocarterus inexspectatus sp. n., habitus. 5, male holotype; 6, female paratype. Scale bar = 1.0 mm.

FIGURES 7–9. Indocarterus inexspectatus sp. n. (paratypes: 7, 8 female; 9, male). 7, anterior part of head; 8, pronotum; 9, protarsus and apical part of protibia. 7, 8, dorsal view; 9, lateral view. Scales bars = 1.0 mm (A, C: Figs 7, 9; B: Fig. 8).

FIGURES 10–17. Indocarterus inexspectatus sp. n. (paratypes). 10, labium; 11, apex of median lobe; 12, 13, median lobe; 14, left paramere, inner surface; 15, left paramere, inner surface; 16, stylus, 17, right laterotergite and stylus. 10, 17, ventral view; 11, 13, dorsal view; 12, 14–16, lateral view. Scale bars: A = 1.0 mm (Fig. 10), B = 0.5 mm (Figs 11–16).