Somoleptus guianensis, Irmler, 2024

Irmler, Ulrich, 2024, Additions to Neotropical species of the genera Lithocharodes Sharp, 1881 and Somoleptus Sharp, 1881 (Coleoptera, Staphylinidae), Contributions to Entomology 74 (1), pp. 13-34 : 13

Somoleptus guianensis sp. nov.

Figs 14a-d , 21B

Material examined.

Holotype: FRENCH GUIANA male; Roura ; 8.4 km SSE; 200 m elevation; 4°40'0"N, 52°13'0"W; flight intercept trap; 29 May-10 Jun 1997; J. Ashe, R. Brooks leg. FG1AB97 182.

Paratypes: FRENCH GUIANA 1 female; same data as holotype 1 KNHM ; 1 female; same data as holotype UIC ; 1 male; Roura ; 18.4 km SSE; 240 m elevation; 4°36'38"N, 52°13'25"W; flight intercept trap; 25-29 May 1997; J. Ashe, R. Brooks leg. KNHM FG1AB97 081 ; 1 female; same location but; 29 May-10 Jun 1997; J. Ashe, R. Brooks leg.; KNHM FG1AB97 180 ; 1 female; same data; UIC ; 1 female; Saül; 7 km N, 3 km NW; Les Eaux Claires; Mt. La Fumée; 490 m elevation; 3°30'46"N, 53°13'19"W; flight intercept trap; 1-8 Jun 1997; J. Ashe, R. Brooks leg.; KNHM FG1AB97 162 ; 1 female; same location but; 7 km N; 0.5 km ESE; 300 m elevation; flight intercept trap; 4-8 Jun 1997; J. Ashe, R. Brooks leg.; KNHM FG1AB97 164 ; 1 female; Cayenne ; 33.5 km S and 8.4 km NW of Hwy D5; 30 m elevation; 4°48'18"N, 52°28'41"W; flight intercept trap; 1-8 Jun 1997; J. Ashe, R. Brooks leg.; KNHM FG1AB97 171 .

Diagnosis.

According to the structure of the paramere and the position of the apical process at inner side of the aedeagal orifice, S. guianensis must be placed into the S. struyvei sub-group of the S. laevis -group. Amongst the Neotropical Somoleptus species, S. guianensis resembles S. struyvei Irmler, 2022 of the same sub-group according to the total size and eye size. However, S. struyvei is slightly longer with 4.9 mm length and eyes are slightly larger with PS:E ratio 2.4, in S. guianensis , PS:E ratio is 2.6. Moreover, the parameres of the aedeagus are distinctly shorter and the processes at the inner side of the aedeagal orifice are more strongly sclerotised.

Description.

Length: 4.5 mm; Colouration: completely black; legs light brown; antennae darker brown.

Head: 0.59 mm long, 0.51 mm wide; eyes slightly prominent; moderately large; PS:E ratio 2.6; postocular sides slightly convex; in posterior half, sides combined with posterior edge semi-circular; inter-antennal furrows indistinct; setiferous punctation moderately deep and sparse; on average, interstices between punctures at least twice as wide as diameter of punctures; surface without microsculpture; shiny; antennae with first antennomere elongate; distinctly longer than half-length of head; second and third antennomere conical; longer than wide; combined half as long as first antennomere; following antennomeres approximately twice as wide as long; anteriad increasing in width. Pronotum: 0.72 mm long, 0.48 mm wide; widest in anterior third; sides approximately parallel; posterior margin obtuse; posterior margin slightly convex; setiferous punctation moderately deep and sparse; on average, interstices twice as wide as diameter of punctures; surface without microsculpture; shiny. Elytra: 0.68 mm long, 0.62 mm wide; humeral angles obtuse; sides slightly divergent posteriad; posterior angles sub-rectangular; posterior margin straight; at suture with short incision; setiferous punctation finer than on pronotum, but as sparse; on average, interstices between punctures at least twice as wide as diameter of punctures. Abdomen with punctation fine and sparse; without microsculpture; shiny; sternite VII and tergite VII of male with straight posterior margin; meso- and meta-tibia with 3 ctenidia each. Aedeagus oval; apically with obtuse prominence; dorsal plate covering nearly total central lobe; endophallus sack-like; weakly sclerotised; apical process with long setae; translocated to inner side of orifice; one third as long as central lobe; parameres extremely long; slender; as long as total length of central lobe; in apical third, slightly curved; in apical half, with several sensillae.

Etymology.

The species name is derived from the Guiana region in north-east South America, where it was collected.

Geography.

French Guiana.

Ecology.

Lowland-forest floor up to 500 m elevation from May to June.

Figures

Figure 21. A. Fore-body of Somoleptus densiceps; B. S. guianensis; C. S. luteicornis; D. S. paramocola; E. S. puntarenae; F. S. umicola. Scale bars: 0.5 mm.

Figures 13 - 16. 13. Somoleptus densiceps; 14. S. guianensis; 15. S. luteicornis; 16. S. paramocola. a. Aedeagus; b. Paramere; c. Sternite VII; d. Tergite VII. Scale bars: 0.5 mm (a, c, d); 0.1 mm (b).