Coccidotrophus socialis Schwarz and Barber

Halstead, David G. H., 2020, New and little known Coleoptera (Silvanidae: Silvaninae) from Central and South America, Insecta Mundi 2020 (842), pp. 1-37 : 17-19

Coccidotrophus socialis Schwarz and Barber

( Fig. 52–57 , 64–66 )

Coccidotrophus socialis Schwarz and Barber 1921: 189 (types examined).

Description. This description is based on two male paratypes and takes into account data from the original description. The illustration of half of the pronotum of a specimen of C. socialis , with sides very obviously narrowed to the middle ( Fig. 54 ), was made from a photograph showing all characteristics of the species. The specimen illustrated was collected in Ecuador with C. cordiae but has not been seen by the author. Length of the two specimens examined 4.1 and 4.3 mm, length to breadth ratios, 54 and 56:10, Schwarz and& Barber (1921) gave length as 3.5 – 4.5 mm, breadth 0.6 – 0.8 mm (i.e., presumably length to breadth ratio of 58 – 56:10); general appearance sub-cylindrical, dark to reddish brown, shining and glabrous.

Head. Slightly broader than long, tapering from in front of eyes to broad, v-shaped emargination, lateral margins (in front of eyes) moderately raised; shallow depressions present above antennal insertions, vertex with very shallow, longitudinal depression; basal half of head rugose and papillate, papillae minute, well separated and each bearing a short, fine (inconspicuous) seta, apical half with normal, sparser puncturation, punctures each with a short, fine seta; eyes in dorsal view rounded, small with small facets, dorsally separated by 8.6× or 10× breadth of eye in dorsal view; antennae robust, funicular segments strongly transverse, apical segments forming narrow club; antennal grooves (beneath head) relatively short ( Fig. 57 ).

Pronotum. Elongate, length to breadth ratio 14.5–15.0:10, slightly to obviously narrowed to middle ( Fig. 52, 54 ), all margins with narrow rim, apical rim less obvious than others, small depressions present by anterior angles; disc more or less flat; anterior angles only slightly developed, not produced in front (semi-lateral view Fig. 53 ); narrow, medial, longitudinal impunctate region extending to apical quarter, puncturation on rest of dorsal side with moderately dense puncturation consisting of elongate, elliptical punctures appearing to be derived mainly from pairs of punctures, some punctures in short rows (puncturation similar to that of C. trinidadensis , Fig. 85 ), interspaces shining.

Elytra. About 3× as long as broad with narrow rim along suture and sides; each elytron with 9 rows of punctures forming striae, a microscopic puncture bearing a minute seta present in front of each strial puncture and a regular interstrial row of these punctures ( Fig. 56 ).

Legs. Male tibiae all with a small apical spine on proximal margin, no other secondary sexual characters present on legs.

Abdomen. Femoral lines on first abdominal ventrite extending to about caudal half; male, last abdominal ventrite with broad depression (similar to although not as deep as that of C. cordiae Fig. 72 ), apical margin of depression with obvious rim.

Male genitalia. ( Fig. 64 – 66 ) Parameres broadest on basal half, moderately tapered to rounded apex, with 7 – 8 long, mainly apical setae but one long seta half-way along outer edge of one paramere in specimen dissected, a similar number of short, fine setae in a group on outer edge within basal half and some of variable size along inner edge and towards apical long setae; median lobe gradually tapered to broad apparently slightly emarginate apex (apex difficult to see in slide preparation); area towards ostium with about 20 rods on each side ( Fig. 64 ); internal sac ( Fig. 65 ) with long sclerite at apex; sternite 8 on each side of apical margin with a few long setae towards middle followed by many very short setae ( Fig. 66 ).

Material examined. Two male specimens examined, one dissected, “Kartabo. Bartica Distr. Brit. Guiana W M Wheeler 1920 / socialis Sz &B Paratype no 24070 USNM [red label]” (Additional type specimens are in the NHML and USNM).

Distribution and habitat. Guyana (types) and Ecuador. Associated with coccids in myrmecodermati on the anttree Tachigalia paniculata .

Figures

Figures 52–63. Coccidotrophus spp., all paratypes except figure 54. 52–57) C. socialis Schwarz and Barber, male. 52) Habitus. 53) Anterior pronotal angle, semi-lateral view. 54) Pronotum (left half), variant with strongly incurved sides. 55) Antenna, enlarged. 56) Elytron, small part including sutural margin enlarged to show rows of punctures. 57) Head, part of left side to show antennal groove. 58–63) C. wheeleri (Schwarz and Barber), male. 58) Habitus. 59) Anterior pronotal angle, semi-lateral view. 60) Antenna, enlarged. 61) Elytron, small part including sutural margin to show rows of punctures. 62) Hind leg enlarged, showing small femoral prominence etc. 63) Head, part of left side to show antennal groove. Scale line = 1.0 mm.

Figures 64–69. Coccidotrophus spp., paratypes, male genitalia and associated sternites. 64–66) C. socialis Schwarz and Barber. 64) Genitalia without internal sac. 65) Internal sac. 66) Sternites 8–9. 67–69) C. wheeleri (Schwarz and Barber). 67) Genitalia without internal sac. 68) Internal sac. 69) Sternites 8–9. Scale lines = 0.2 mm.

Figures 85–90. Coccidotrophus trinidadensis new species, male holotype. 85) Habitus, inset illustrations of a few paired head punctures, also antennomeres 1–2; other puncture illustrations given as examples of pronotal paired punctures and elytral strial punctures. 86) First and second abdominal ventrites. 87–90) Genitalia and associated sclerites. 87) Genitalia, without most of internal sac. 88) Paramere enlarged. 89) Internal sac. 90) Sternites 8–9. Scale lines for Figures 85–86 = 2.0 mm, for Figures 87, 89–90 = 0.2 mm.

Figures 70–74. Coccidotrophus cordiae Barber. 70) Habitus, male; Ecuador specimen. 71) antenna, enlarged. 72) Abdomen and base of metasternum of male. 73) Pronotum of female, form with more rounded sides. 74) Habitus male, holotype (Bolivia). Scale line = 2.0 mm.