Proditomus Schauberger, 1934

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 : 360

Proditomus Schauberger, 1934

Proditomus Schauberger, 1934b: 232

Type species Proditomus mirus Schauberger, 1934 , by original designation.

Diagnosis. Proditomus is similar to Dixus Billberg, 1820 in head wide, without neck constriction and mentum with long median tooth, but differs in having anterior margin of clypeus deeply concave, labrum with deep emargination anteriorly, bilobed, and sides of pronotum not bordered basally.

Description. Body ( Fig. 28 ) punctate, superior surface very convex, covered with very fine, scattered setae, obviously most of them rubbed off (as a very old specimen), and hence difficult to observe. Punctation on head and pronotum coarse and rather dense, on elytra fine and sparse. Head large, as wide as pronotum, without neck constriction and with only one long seta (supraorbital setigerous pore) near inner margin of eyes on each side. Lateral margin of frons above insertion of antennae somewhat roundly widened forming an angulate projection on each side before eye. Eyes small, noticeably removed from buccal fissure ventrally. Tempora long, slightly convex, evenly curved to neck. Labrum with deep emargination anteriorly, bilobed. Аnterior margin of clypeus deeply concave at middle. Mentum ( Fig. 25 ) with large median tooth, without setae. Epilobes wide, prolonged medially up to tooth apex where they connect with each other. Ligular sclerite very wide, long, its sides roundly converging anteriorly and apex shortly sharpened, apicad distinctly deflexed; dorsal side with numerous rather long setae, ventrally unsetose. Paraglossae very small and narrow, much shorter than ligular sclerite, glabrous. Basal palpomere not carinate. Mandibles long, evenly curved, with acute apices only slightly blunted at tips. Аntennae slender, with antennomeres narrow, much longer than wide. Pronotum cordate, strongly narrowed posteriorly, almost parallel-sided in apical third and before almost right basal angles, with apical angles acute, projecting anteriad. Pronotal apical and basal margins not bordered, sides very narrowly bordered in apical half only. Mesothorax and extreme base of elytra narrowed forming a short neck-like constriction with scutellum above. Elytral base not bordered, sides border beginning from base of stria 7. Metacoxa without a posteromedial setigerous pore, punctate. Profemur not denticulate along inner margin. Protibia with prominent outer angle and with a transverse row of strong ventroapical setae. Metatrochanter short, about 0.3 times as long as metafemur. Metatarsomere 1 approximately as long as 2+3.

Composition and distribution. Includes only one species, Proditomus mirus , from “Turkestan”.

Remarks. Re-examination of the holotype confirmed Schauberger’s opinion (1934) that this taxon is closest to Dixus Billberg, 1820 and warrants separate generic status.

Figures

FIGURES 25–29. Proditomus mirus Schauberger, 1934 (holotype). 25, labium; 26, right laterotergite and stylus; 27, stylus; 28, habitus; 29, left metepisternum. 25, 26, 29, ventral view; 27, lateral view; 28, dorsal view. Scale bars = 1.0 mm (A: Fig. 25, 29; C: Fig. 28), 0.5 mm (B: Figs 26, 27).