Seeversiella luridicollis Gusarov

Gusarov, Vladimir I., 2003, A revision of the genus Seeversiella Ashe, 1986 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 142, pp. 1-102 : 70-73

20. Seeversiella luridicollis Gusarov , sp. n. ( Figs. 278­290 )

Type material. Holotype ,, COSTA RICA: San Jose/Cartago: Cerro Buenavista, km 89 Int. Amer. Hwy., 9°33'00"N 83°45'30"W, 3200 m, leaf litter (R.Anderson), 18.vi.1998 ( KSEM).

Paratypes: COSTA RICA: San Jose/Cartago: 7, 7, same data as the holotype; Cartago: 13, 4, Cerro de la Muerte, Pan American Highway, km 89, 3300 m, elfin bamboo forest litter (R.Anderson), 10.ii.1996 (all ­ KSEM).

Diagnosis. Seeversiella luridicollis can be distinguished from other species of Seeversiella by having dark brown body with contrasting lighter pronotum and elytra; temples 1.4­2.1 times as long as eyes; elytra much shorter than pronotum; reduced wings (shorter than elytra); by lacking the medial emargination at the posterior margin of the male tergum 7 ( Fig. 278 ); tergum 8 with four pairs of macrosetae; by the distinct shape of aedeagus ( Figs. 282­289 ) and spermatheca ( Fig. 290 ).

Seeversiella luridicollis differs from S. curtipennis and S. lativentris in having glossy pronotum with weak microsculpture; tergum 8 with four pairs of macrosetae; medial lamellae of internal sac short ( Fig. 288 ), the apices of lamellae not protruding from retracted sac ( Fig. 282 ); the apex of median lobe in parameral view broad, without basal constriction ( Figs. 282­283 ); and S­shaped spermatheca ( Fig. 290 ).

Seeversiella luridicollis differs from S. micralymma in having wider apex of median lobe (in parameral view) ( Figs. 282­283 ; 295­296) and S­shaped spermatheca ( Fig. 290 ).

Description. Length 2.0­ 2.5 mm. Head and abdomen dark brown; pronotum reddish brown to brownish orange; elytra brown to brownish yellow; antennae, mouthparts and legs brown.

Head surface glossy, with fine and weak isodiametric microsculpture, and fine and poorly visible punctation, distance between punctures equals 2­3 times their diameter. Temples 1.4­2.1 times as long as eyes. Antennal article 2 as long as 3, articles 4­5 elongate, 6­7 subquadrate, 8­10 slightly transverse (ratio 1.5­2.0).

Pronotum slightly transverse, 1.1 times as wide as head, width 0.46­0.51 mm, length 0.40­0.47 mm, width to length ratio 1.1, surface glossy, with fine isodiametric microsculpture, and fine and poorly visible punctation, distance between punctures equals 2­3 times their diameter. Elytra wider and much shorter (measured from humeral angle) than pronotum (pronotal length to elytral length ratio 1.4), 1.6 times wider than long, glossy, with fine and weak isodiametric microsculpture, and fine punctation, distance between punctures equals 1­2 times 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 1­3 times their diameter on terga 3­5 and 2­4 times on tergum 7. Apical margin of tergum 7 without white palisade fringe. Tergum 8 with four pairs of macrosetae ( Figs. 278, 280 ).

In males posterior angles of tergum 3 not projecting; tergum 7 without medial carina or tubercle; posterior margin of tergum 8 without emargination ( Fig. 278 ).

Aedeagus as in Figs. 282­289 . Apex of paramere narrow, proximal seta approximately as long as the other three setae ( Fig. 289 ).

Spermatheca as in Fig. 290 .

Distribution. Known from Cerro de la Muerte, Costa Rica ( Fig. 389 ). Natural History. Seeversiella luridicollis was collected in forest litter at altitude of 3200­3300 m.

ML – medial lamellae; SLD – sclerite of lateral diverticulum of internal sac.

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 278 ­ 281. Abdominal segment 8 of Seeversiella luridicollis Gusarov, sp. n. (paratypes from Cerro Buenavista, Costa Rica). 278 – male tergum 8; 279 – male sternum 8; 280 – female tergum 8; 281 – female sternum 8. Scale bar 0.2 mm.

FIGURES 282 ­ 285. Aedeagus of Seeversiella luridicollis Gusarov, sp. n. (holotype). 282 – median lobe, parameral view; 283 – apex of median lobe, parameral view; 284 – median lobe, lateral view; 285 – apex of median lobe, lateral view. Scale bar 0.2 mm (282, 284), 0.1 mm (283, 285).

FIGURES 286 ­ 290. Genitalia of Seeversiella luridicollis Gusarov, sp. n. (286, 289, holotype; 287 ­ 288, 290, paratypes from Cerro Buenavista, Costa Rica). 286 – details of internal sac retracted into median lobe, lateral view; 287 – copulatory piece, lateral view; 288 – everted internal sac, parameral view; 289 – apex of left paramere; 290 ­ spermatheca. Scale bar 0.2 mm (286), 0.1 mm (287 ­ 290).