Seeversiella lativentris Gusarov

Gusarov, Vladimir I., 2003, A revision of the genus Seeversiella Ashe, 1986 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 142, pp. 1-102 : 68-70

19. Seeversiella lativentris Gusarov , sp. n. ( Figs. 265­277 )

Type material. Holotype ,, COSTA RICA: San Jose: 2 km S Villa Mills, 3000 m, ridgetop oak forest litter (R.Anderson), 10.ii.1996 ( KSEM).

Paratypes: COSTA RICA: San Jose: 78 specimens, same data as the holotype ( KSEM).

Diagnosis. Seeversiella lativentris can be distinguished from other species of Seeversiella by having brown body with lighter pronotum and elytra; temples 1.5­1.8 times as long as eyes; elytra much shorter than pronotum; reduced wings (shorter than elytra); by lacking clear medial emargination at posterior margin of male tergum 7 ( Fig. 265 ); tergum 8 with three pairs of macrosetae; by the distinct shape of aedeagus ( Figs. 269­276 ) and spermatheca ( Fig. 277 ).

Seeversiella lativentris differs from S. curtipennis in having stronger basal constriction of the apex of median lobe (in parameral view) ( Figs. 269­270 ; 251­252).

ML – medial lamellae.

Seeversiella lativentris differs from S. luridicollis and S. micralymma in having matte pronotum with strong isodiametric microsculpture; tergum 8 with three pairs of macrosetae; medial lamellae of internal sac long ( Fig. 274 ), the apices of lamellae protruding from retracted sac ( Fig. 269 ); different shape of the median lobe ( Figs. 269­270 ; 282­283; 295­ 296) and L­shaped spermatheca with large umbilicus ( Fig. 277 ).

Description. Length 2.0­ 2.6 mm. Head and abdomen brown to dark brown; pronotum reddish brown; elytra reddish brown or yellowish brown; antennae and legs brown.

Head surface matte, with fine and dense isodiametric microsculpture, and fine and poorly visible punctation. Temples 1.5­1.8 times as long as eyes. Antennal article 2 as long as 3, article 4 transverse (ratio 1.2), 5­10 strongly transverse (ratio 1.5­2.0).

Pronotum slightly transverse, 1.2 times as wide as head, width 0.41­0.47 mm, length 0.34­0.43 mm, width to length ratio 1.1, surface matte, with fine and dense isodiametric microsculpture, and fine and poorly visible punctation. Elytra wider and much shorter (measured from humeral angle) than pronotum (pronotal length to elytral length ratio 1.3), 1.7 times wider than long, matte, with fine and weak isodiametric microsculpture, and fine punctation, distance between punctures equals ½­1 time their diameter. Wings reduced to short vestiges, shorter than elytra.

Abdominal terga glossy, with fine microsculpture consisting of transverse meshes, with fine punctation, distance between punctures equals 1­4 times their diameter on terga 3­5 and 3­5 times on tergum 7. Apical margin of tergum 7 without white palisade fringe. Tergum 8 with three pairs of macrosetae ( Figs. 265, 267 ).

In large males posterior angles of tergum 3 projecting as spines up to half as long as tergum 3 (measured medially); tergum 7 with medial carina along midline, the carina up to ½ as long as tergum length; posterior margin of tergum 8 without clear emargination ( Fig. 265 ).

Aedeagus as in Figs. 269­276 . Apex of paramere narrow, proximal seta approximately as long as the other three setae ( Fig. 273 ).

Spermatheca as in Fig. 277 .

Distribution. Known from Cerro de la Muerte, Costa Rica ( Fig. 389 ).

Natural History. Seeversiella lativentris was collected in forest litter at altitude of 3000 m.

Figures

FIGURE 389. Geographical distribution of eleven species of Seeversiella (with very short elytra) in the high mountains of Costa Rica. Isohypses 1000 m, 2000 m and 3000 m are shown. Areas above 2000 m are grey and those above 3000 m are solid black.

FIGURES 265 ­ 268. Abdominal segment 8 of Seeversiella lativentris Gusarov, sp. n. (paratypes from Villa Mills, Costa Rica). 265 – male tergum 8; 266 – male sternum 8; 267 – female tergum 8; 268 – female sternum 8. Scale bar 0.2 mm.

FIGURES 269 ­ 277. Genitalia of Seeversiella lativentris Gusarov, sp. n. (paratypes from Villa Mills, Costa Rica). 269 – median lobe, parameral view; 270 – apex of median lobe, parameral view; 271 – median lobe, lateral view; 272 – apex of median lobe, lateral view; 273 – apex of left paramere; 274 – everted internal sac, parameral view; 275 – everted internal sac, lateral view; 276 – details of internal sac retracted into median lobe, lateral view; 277 ­ spermatheca. Scale bar 0.2 mm (269, 271, 274 ­ 276), 0.1 mm (270, 272 ­ 273, 277).