Seeversiella microphthalma Gusarov

Gusarov, Vladimir I., 2003, A revision of the genus Seeversiella Ashe, 1986 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 142, pp. 1-102 : 83-86

24. Seeversiella microphthalma Gusarov , sp. n. ( Figs. 331­343 )

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: 8, same data as the holotype ( KSEM).

Diagnosis. Seeversiella microphthalma can be distinguished from other species of Seeversiella by having uniformly brown body; small eyes (temples 4.0­4.3 times as long as eyes); elytra much shorter than pronotum; reduced wings (shorter than elytra); by lacking clear medial emargination at the posterior margin of male tergum 8 ( Fig. 331 ); tergum 8 with four pairs of macrosetae; by the distinct shape of aedeagus ( Figs. 335­340, 342­ 343 ) and spermatheca ( Fig. 341 ).

Seeversiella microphthalma differs from S. impressicollis in having less asperate pronotal punctation; in males pronotum without medial impression, posterior angles of male tergum 3 projecting as spines; lateral diverticula of internal sac without long spiniform sclerites ( Figs. 343 ; 316, 318); L­shaped spermatheca with larger distal portion ( Fig. 341 ).

Seeversiella microphthalma differs from S. sulcicollis in having larger body, less asperate pronotal punctation; in males pronotum without medial furrow, posterior angles of male tergum 3 projecting as spines; lateral diverticula of internal sac without strong denticulate sclerites ( Figs. 343 ; 326­328).

Seeversiella microphthalma differs from S. geostiboides in having pubescence in the lateral portions of pronotum directed towards the midline and obliquely posteriorly; in wider apex of median lobe (in parameral view) ( Figs. 335­336 ; 348­349); and different shape of the distal portion of spermatheca ( Figs. 341 ; 355).

Seeversiella microphthalma differs from S. flavida and S. adusta in having abdominal tergum 8 with four pairs of macrosetae.

Seeversiella microphthalma differs from S. paramoana in having concave but not emarginate apex of median lobe (in lateral view) ( Figs. 338­339 ; 379­380).

Description. Length 2.5­2.8 mm. Body brown.

Head surface glossy, with fine and weak isodiametric microsculpture, with fine and asperate punctation, distance between punctures equals 1­2 times their diameter. Temples 4.0­4.3 times as long as eyes. Antennal article 2 as long as 3, article 4 subquadrate, 5­10 transverse.

Pronotum slightly transverse, 1.2 times as wide as head, width 0.46­0.50 mm, length 0.43­0.47 mm, width to length ratio 1.1, surface glossy, with fine isodiametric microsculpture, with fine and asperate punctation, distance between punctures equals 1­2 times their diameter. Elytra wider and much shorter (measured from humeral angle) than pronotum (pronotal length to elytral length ratio 1.4), 1.8 times wider than long, glossy, with poorly visible microsculpture, with fine and asperate punctation, distance between punctures equals 1­1.5 times their diameter, punctures stronger than on pronotum. Wings reduced to short vestiges, shorter than elytra.

Abdominal terga glossy, terga 3­5 with microsculpture consisting of transverse meshes, and with fine punctation, distance between punctures equals 2­4 times their diameter; tergum 7 with microsculpture consisting of transverse meshes and with fine and sparse punctation, distance between punctures equals 3­5 times their diameter. Apical margin of tergum 7 without white palisade fringe. Tergum 8 with four pairs of macrosetae ( Figs. 331, 333 ).

In the only known male the posterior angles of tergum 3 projecting as sharp spines half as long as tergum (measured medially); tergum 7 in front of posterior margin with medial carina half as long as the tergum; posterior margin of tergum 8 without clear medial emargination ( Fig. 331 ).

Aedeagus as in Figs. 335­340, 342­343 . Apex of paramere narrow, proximal seta approximately as long as the other three setae ( Fig. 337 ).

Spermatheca as in Fig. 341 .

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

Natural History. Seeversiella microphthalma 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 331 ­ 334. Abdominal segment 8 of Seeversiella microphthalma Gusarov, sp. n. (331 ­ 332, holotype; 333 ­ 334, paratype from Villa Mills, Costa Rica). 331 – male tergum 8; 332 – male sternum 8; 333 – female tergum 8; 334 – female sternum 8. Scale bar 0.2 mm.

FIGURES 335 ­ 343. Genitalia of Seeversiella microphthalma Gusarov, sp. n. (335 ­ 340, 342 ­ 343, holotype; 341, paratype from Villa Mills, Costa Rica). 335 – median lobe, parameral view; 336 – apex of median lobe, parameral view; 337 – apex of left paramere; 338 – median lobe, lateral view; 339 – apex of median lobe, lateral view; 340 – details of internal sac retracted into median lobe, abparameral view; 341 ­ spermatheca; 342 ­ 343 – details of internal sac retracted into median lobe, lateral view. Scale bar 0.2 mm (335, 338, 340, 342 ­ 343), 0.1 mm (336 ­ 337, 339, 341).