Omolabus megalomus Hamilton

HAMILTON, ROBERT W., 2005, Omolabus Jekel in north and central America (Coleoptera: Attelabidae), Zootaxa 986 (1), pp. 1-60 : 52-53

Omolabus megalomus Hamilton , new species

( Figs. 1 , 20 , 68, 69, 70 & 71)

Type locality. Columbia, Leticia

Type holder. United States National Museum ( USNM)

Type material. The type series consists of eight specimens. The holotype male [dissected] is labeled as follows: Columbia, Leticia , vii­1970, Eugenia, G Vogt ( USNM). The allotype female is labeled the same as holotype. The sex and label data of the paratypes are as follows: 3 females, Costa Rica, Turialba, 900 m, A Heyne ( ZMHB); 1 female [distinctly smaller than allotype] (labeled same as primary types) ( USNM); 1 female, Amazonas, Brazil, Benjamin Constant, Rio Javary, March­1942, A Rebaut collector ( AMNH); 1 female, Peru, Loreto, Callicebus Res. Station, Mishana, Rio Nanay, 25 km SW Iquitos, 120 mtrs. 10–17, I[January]­1980, tropical wet forest, JB Heppner ( USNM).

Size range. Male: 8.3 x 3.6 mm (n=1); Female: 7.1 x 3.0 to 8.6 x 4.0 mm (n=4).

Description. Body reddish­brown throughout. Head with minute shallow punctures; punctures more numerous near eyes and on frons; base with fine transverse strigae in male; frons with wide concavity; concavity extending into vertex; vertex flat; eyes reniform, not protuberant, flush with surface of the head. Rostrum subequal to head in length, about twice as wide as frons at apex; dorsal base smooth, flat; lateral base moderately punctured; dorsally beyond antennal insertions with minute punctures; postlabial area with pair of closely set blunt tipped projections in male. Antennae inserted near basal ¼ of rostrum in both sexes; club elongate­compact, distinctly shorter than funicle; middle and terminal club segments nearly subequal, basal segment slightly longer; funicular segment 1 globose, 2 length of scape; segment 2 strongly clavate, subequal in length to segment 1; segments 3 and 4 like 2 but 3 longer than 2 and 4 longer than 3; 5 and 6 like 2 but more robust apically; 7 like 5 and 6 but widened apically at union with club. Pronotum smooth, with sparse minute punctures, with pair of round weakly impressed fovea on either side of middle, with oblique line­like grooves on either side near base; sides minutely strigate; anterior collar indistinct. Scutellum wide, twice as wide as long, 4­sided, posterior margin broadly rounded, with some minute round shallow punctures. Elytra longer than wide, widest across humeri, in dorsal view distinctly narrowed posteriorly, with weak depression behind scutellum; humeri simple, rounded, moderately protuberant, with dorsal posthumeral hump­like protuberances; striae small, distinct throughout, larger and more deeply impressed in basal 1/3 of elytra; intervals distinctly convex at elytral base; becoming flat and wider beyond elytral base, with numerous minute punctures. Profemora in male with ventral bump­like minutely strigate protuberance; evenly swollen in female.

Distribution. ( Fig. 1 ). Three females from the ZMHB collection in Berlin were recorded from Turrialba, Costa Rica. The other specimens are from the South American countries of Columbia and Peru. This is primarily a South American species that ranges into lower Central America.

Comments. This is a distinct species recognized by the shiny reddish­brown color, non­protuberant eyes, smooth pronotum and the dorsal post­humeral protuberances (Figs. 68–71). Dorsal posthumeral protuberances also occur in O. callosus and O. quadratus but O. callosus is black in color and O. quadratus is much smaller and has unique pronotal sculpture. The male of O. megalomus is unique in having the profemur armed with a distinct strigate protuberance (Fig. 69).

Host plants. The host plant association for this species is unknown.

Name derivation. The specific name is in reference to the dorsal posthumeral protuberances and means large shoulders.

Figures

FIGURES 1 – 8. Distribution of Omolabus species: 1) Omolabus veracruensis (square), Omolabus spinipectus (circle), Omolabus megalomus (triangle), Omolabus fasciventris (open triangle) 2) Omolabus ligulatus (circle), Omolabus quadratus (open triangle) 3) Omolabus heterocerus (triangle), Omolabus angulipennis (circle) 4) Omolabus laesicollis 5) Omolabus corvinus 6) Omolabus sedatus (circle), Omolabus longiclava (triangle) 7) Omolabus callosus 8) Omolabus conicollis.

FIGURES 20 & 21. Male genitalia of Omolabus species, 64 X: a) tegmen, dorsal b) median lobe with endophallic sac and transfer apparatus in repose, ventral view 20 c) transfer apparatus, lateral view, 21 c) transfer apparatus, dorsal view 20) Omolabus megalomus, Columbia, Leticia 21) Omolabus conicollis, Costa Rica, San Jose.