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

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Coccidotrophus socialis Schwarz and Barber


Coccidotrophus socialis Schwarz and Barber  

( Fig. 52–57 View Figures 52–63 , 64–66 View Figures 64–69 )

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 View Figures 52–63 ), 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 View Figures 52–63 ).

Pronotum. Elongate, length to breadth ratio 14.5–15.0:10, slightly to obviously narrowed to middle ( Fig. 52, 54 View Figures 52–63 ), 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 View Figures 52–63 ); 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 View Figures 85–90 ), 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 View Figures 52–63 ).

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 View Figures 70–74 ), apical margin of depression with obvious rim.

Male genitalia. ( Fig. 64 – 66 View Figures 64–69 ) 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 View Figures 64–69 ); internal sac ( Fig. 65 View Figures 64–69 ) 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 View Figures 64–69 ).

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   .


Natural History Museum, Tripoli


Smithsonian Institution, National Museum of Natural History














Coccidotrophus socialis Schwarz and Barber

Halstead, David G. H. 2020

Coccidotrophus socialis

Schwarz EA & Barber HS 1921: 189