Neocorimus thomasi Halstead, 2020

Halstead, David G. H., 2020, New and little known Coleoptera (Silvanidae: Silvaninae) from Central and South America, Insecta Mundi 2020 (842), pp. 1-37 : 8-10

Neocorimus thomasi Halstead , new species

( Fig. 18–27 )

Description. The following description is based on a single male specimen. Length 2.7 mm; ratio of length to breadth 22:10. Dark brown, moderately shining, lateral margins of elytra and appendages appearing slightly lighter than rest of body; pubescence short, recumbent and golden.

Head. Twice as broad as long; very slightly depressed on each side by eyes ( Fig. 18 ); front margin slightly raised; clypeus virtually straight; eyes of moderate size, about twice as long as broad, separated dorsally across head by about 7× breadth of eye in dorsal view; antenna short with very gradually developed club of five antennomeres, 9 shorter and more transverse than 10, 10 larger than other antennomeres, 11 slightly longer than 10 and with pointed apex, antennomere 1 and base of 2 hidden from above by margin of head ( Fig. 18–19 ); punctures fine (all setiferous) on frontal triangle, larger but shallow on each side towards eyes; deep, ventral antennal grooves present, inner margins of grooves almost straight and moderately convergent from base (behind eyes) to front ( Fig. 19 ); dense puncturation and long setae on submentum near mentum (without secondary sexual setiferous pit).

Pronotum. Transverse (ratio of breadth to length 15:10), strongly narrowed to apex, slightly narrowed to base ( Fig. 18 ), nearly as broad across base as base of elytra; anterior margin very slightly sinuate (raised on each side); anterior angles produced, lateral limit indicated by inconspicuous indentations; sides explanate, lateral margin gently curved medially, shallowly undulating before base; disc with shallow depression medially before base; base with narrow marginal rim; punctures dense but shallow becoming larger towards sides where puncturation is reticulate, large and oval on explanate margins (largest longer than twice an eye facet diameter); sides of prosternum strongly declivous on each side near middle, giving impression that prosternum is prolonged to apical third.

Elytra. Short, ratio of length to breadth 12:10; striae absent, only rows of setiferous tubercles present including 5 rows of closely aligned setiferous tubercles consisting of 1 row along suture plus 4 slightly raised rows on disc (latter apparently equivalent to raised interstriae such as are found in Metacorimus mroczkowskii Halstead and other Silvaninae ), 4 or 5 uneven rows ( Fig. 21 shows a small part of elytron, including mid-region of second and third raised rows) and 6 or 7 uneven rows between margin of disc and upturned explanate lateral margin; all setae directed caudally.

Legs. In male (female, unknown but characters given here are assumed to be secondary sexual ones), mesotrochanter with apex of trochanter (by inner side of femur) very slightly produced (inconspicuous); metatrochanter with apex slightly but obviously produced and recurved ( Fig. 22 ).

Male genitalia ( Fig. 23–27 ). Parameres curved, with two long apical setae plus a few short setae at apex, toothed prominence on apical third ( Fig. 23–24 ); area towards ostium with about 22 rods on each side; median strut short, apically broad; median lobe with point at apex, line of 6 short setae (3 on each side) across middle of ventral side; internal sac with many small caudally directed spines ( Fig. 25 ); sternite 8 with two long and 6 or 7 shorter setae on each side ( Fig. 26–27 ).

Material examined. Holotype male “N. VENEZUELA Estado Aragua P. Nac. Henri Pittier, Campo Experimental CENIAP Pozo del Diablo 400m / FOG 16. 11. v. 1990 Gallery forest . Cassia grandis J. G. Davies / Tray 16 / 355 / Bristol University Exped. Brit. Mus. Nat. Hist. 1992-6.” ( NHML).

Etymology. This species is named in honour of the late Dr. Michael C. Thomas. Michael was an excellent taxonomist whose beetle studies covered various families. He became primarily interested in some of the cucujoid families including the Silvanidae , Cucujidae , and Laemophloeidae , on which he published the results of several very important, major taxonomic studies.

Figures

Figures 18–22. Neocorimus thomasi new genus, new species, male holotype. 18) Habitus, closely aligned raised rows of tubercles indicated by dots on elytra. 19) Head, part, in latero-ventral view to show antennal groove. 20) Antenna, enlarged.21) Elytral disc, small part enlarged to show rows of tubercles on part of mid-region including second and third rows. 22) Hind leg. Scale line =1.0 mm.

Figures 23–27. Neocorimus thomasi new genus, new species, male holotype, genitalia and associated sternites. 23) Genitalia without internal sac. 24) Paramere, apex enlarged. 25) Internal sac. 26) Sternites 8–9. 27) Sternite 8, part enlarged. Scale lines = 0.2 mm.