Actenoncus foersteri (Andrewes) Andrewes, 2009

Tian, Ming-Yi & Deuve, Thierry, 2009, A review of the genus Actenoncus Chaudoir (Coleoptera: Caraboidea: Orthogoniini), Zootaxa 2135, pp. 57-64 : 63-64

Actenoncus foersteri (Andrewes) , new combination

( Figs. 4 , 7 and 10 )

Orthogonius foersteri Andrewes, 1931: 59 ; Lorenz, 2005: 391

Diagnosis. Small, right mandible with an evident median tooth, labrum slightly emarginated at frontal margin, head and pronotum sparsely punctate, elytral striae deep, striate-punctate; abdominal ventrite VII shallowly emarginated at apical margin in male.

Length: 12.5 mm, width: 5.0 mm.

Dark brown, shiny. Habitus as in Fig. 4 .

Surface smooth, head and pronotum sparsely punctate, elytral punctate-striate and lined. Microsculptural meshes densely isodiametric on elytra, but faint on head and pronotum.

Head as long as wide, eyes very large and extraordinary prominent, neck constricted, frons and vertex rather flat, labrum with frontal margin slightly emarginated or almost straight; frontal impressions deep and wide, not extending to the level of fore margins of eyes; clypeus bisetose, surface quite even; mandibles rather short, right mandible with an evident median tooth; ligula small and narrow, bisetose at apex; palpi rather stout, subcylindrical, maxillary palpomere 3 as long as 4, both glabrous; labial palpomere 2 slightly longer than 3, palpomere 2 asetose at subapex in inner margin; mentum without median tooth, asetose, submentum with a pair of setae; palpiger unisetose; antennae strongly stout and rather long, extending beyond basal onefourth of elytra; pubescent from basal one-third of antennomere 4; antennomere 2 wider than long, antennomere 1 as long as 4, slightly longer than 3, and twice as long as 2.

Pronotum strongly transverse, PW/PL=1.8, disc convex; sides evenly expanded, widest at a little before middle, lateral expanded margins well defined, wide and distinctly reflexed; fore and hind angles rounded; both fore and hind transversal impressions distinct, basal foveae large and deep.

Elytra elongate ovate, EL/EW=1.4, convex; base unbordered, widest a little behind middle, sides somewhat paralleled; apex broadly truncate, outer angles rounded, slightly but distinctly contracted near inner angle, making a denticle; elytral striae rather deep, punctate-striate and lined; intervals convex, subequal in width in middle, smooth and without setiferous pore.

Prosternal process unbordered at apex. Hind tarsomere 4 bilobed at apex. Abdominal ventrite VII with two pairs in male and female, that of male shallowly emarginated at apical margin ( Fig. 7 ).

Male genitalia. The median lobe of aedeagus rather slender, apical portion slightly bent, sharp at apex in profile, the apical lamella very short, and broad ( Fig. 10 ).

Remarks. According to Chaudoir (1871), the right mandible with or without an evident median tooth is a crucial character to distinguish Orthogonius Macleay and Actenoncus Chaudoir. Therefore, Andrewes placed this species into genus Orthogonius since there is an evident median tooth on its right mandible. But further comparisons showed that almost all other important generic character states of Actenoncus can be found in O.

foersteri apart from the teethed right mandible. Therefore, this species is transferred into Actenoncus . Within the genus, A. foersteri is most similar to A. wallacei n. sp., and the main differences between them have been pointed out above.

Distribution. Indonesia, occurring in Sumatra.

Materials examined. 1 female, the holotype, “Indrapoura, Sumatra, J. Weyers Collection, E. Ronsseau”, and “ Orthogonius försteri , Type, Andr., 1931 ” ( IRSNB); 1 male, a paratype, same data as the holotype ( IRSNB); 1 male, “Palembang, Sumatra” and “Museum Paris, Ex. Coll. M. Maindron, Coll. G. Babault, 1930”( MNHN).

Figures

FIGURES 1 – 4. Habiti of Actenoncus. 1. A. ater, male, 2. A. wallacei, n. sp., female, holotype, 3. A. punctatus, male, holotype, 4. A. foersteri, male. scale bar: 10.0 mm.

FIGURES 5 – 10. Male abdominal ventrite VII (Figs. 5 – 7) and median lobes of aedeagus, lateral and dorsal views (Figs. 8 – 10) of Actenoncus. 5, 8. A. ater, 6, 9. A. punctatus; 7, 10. A. foersteri. scale bar: 10.0 mm, A for Figs 5 – 7; B for Figs. 8 – 10.