Eunausibius Grouvelle

Halstead, David G. H., 2020, New and little known Coleoptera (Silvanidae: Silvaninae) from Central and South America, Insecta Mundi 2020 (842), pp. 1-37 : 26-27

Eunausibius Grouvelle

Eunausibius Grouvelle 1913: 314 .

Discussion. Two species originally described in Eunausibius by Parsons (1974) are transferred to Nausibius as follows: Nausibius lophius (Parsons) new combination (= Eunausibius lophius Parsons ) and Nausibius salutaris (Parsons) new combination (= Eunausibius salutaris Parsons ) and Eunausibius wheeleri Schwarz and Barber , is placed in Coccidotrophus (see above in this paper). The description of one new species discovered during this study makes a total of three within Eunausibius .

Diagnosis. Body elongate, moderately cylindrical, total length within species belonging to the genus can show considerable variation; for E. jatahyensis new species, the range of the eight specimens examined (the type series) is 3.71–9.60 mm, and that of seventeen of E. elongatus 3.00– 5.43 mm. Head with deep convergent antennal grooves beneath ( Fig. 101 ). Antenna short with first antennomere hidden beneath genal margin and a gradually to more obviously developed club of four segments. Pronotum with anterior angles not strongly developed but lateral limit either defined by an inward expansion of the lateral pronotal rim joining a short impressed line ( Fig. 91 , 98–99 ) or just a small impression on the lateral rim. Males of the three known species with a small metafemoral tooth (see Fig. 103 ) and metatibiae striate on proximal side. Elytra each with 9 rows of punctures forming striae or punctate striate. Striae terminating before elytral apex, 6 and 7 of equal length and shorter than rest. Eunausibius and Coccidotrophus are similar genera, for comparisons see the genus diagnosis for the latter.

Figures

Figures 98–102. Eunausibius jatahyensis, new species, types. Dots on pronotal disc show position of narrow, medial impunctate region. 98) Habitus, holotype male (Jatahy). 99) Habitus, paratype female (Jatahy). 100) Head, paratype female with smaller eyes dorsal view (Minas Gerais). 101) Head of holotype, ventral view to show eyes plus deep antennal grooves. 102) Elytron, small part enlarged (margin of suture on left) to show strial punctures, also very short, fine setae. Scale lines = 2.0 mm.

Figures 91–97. Eunausibius spp. 91–94) E. tenebrionoides (Grouvelle), male holotype. 91) Habitus, inset enlarged view of metafemoral spine. 92) First abdominal ventrite. 93–94) Genitalia and associated sternites. 93) Sternites 8–9. 94) Parameres and median lobe. 95–97) E. jatahyensis, new species, male holotype. 95) First abdominal ventrite. 96–97) Genitalia and associated sternites. 96) Sternites 8–9. 97) Parameres and median lobe. Scale lines for Figures 91, 92 and 95 = 2.0 mm, for Figures 93–97 (94 and 97 to same scale) = 0.5 mm.

Figures 103–110. Eunausibius elongatus (Grouvelle), male. 103) Habitus, dots on pronotal disc show position of narrow, medial impunctate region. An example of the pronotal puncturation is included. 104) First abdominal ventrite. 105) Elytron, small part enlarged (margin of suture on left) to show strial punctures with associated comparatively long, conspicuous setae, each above a strial puncture and similar setae in a line on interstriae. 106) Antenna, enlarged. 107) Pronotal punctures, an enlargement of some of those near the anterior margin to show their setae. 108–110) Genitalia and associated sternites. 108) Genitalia without internal sac. 109) Internal sac. 110) Sternites 8–9. Scale lines for Figure 103 (104 also to same scale) = 2.0 mm, for Figures 108–110 = 0.2 mm.