Seeversiella mexicana Gusarov

Gusarov, Vladimir I., 2003, A revision of the genus Seeversiella Ashe, 1986 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 142, pp. 1-102 : 40-42

10. Seeversiella mexicana Gusarov , sp. n. ( Figs. 135­149 )

Type material. Holotype ,, MEXICO: Oaxaca: 4.6 km S Suchixtepec, 2150 m, leaf litter in riparian alder forest (R.S.Anderson), 23.vii.1992 ( KSEM).

Paratypes: MEXICO: Oaxaca: 2, 5, same data as the holotype;, 2, ditto but 5.1 km S Suchixtepec, oak, pine and alder forest litter, 25.vii.1992;, 4, ditto but 24.vii.1992; Guerrero: 3, 4, 71 km NE Atoyac de Alvarez, 1700 m, forest litter (J.S.Ashe), 25.vii.1992; 3,, 5.6 km SW Filo de Caballo, 2310 m, alder forest litter (R.S.Anderson), 13.vii.1992 (all ­ KSEM).

Diagnosis. Seeversiella mexicana can be distinguished from other species of Seeversiella by having brown body; temples 1.2­2.0 times as long as eyes; glossy pronotum with weak isodiametric microsculpture; elytra longer or a little shorter than pronotum (elytral length to pronotal length ratio 1.2­0.9); wings fully developed or reduced; tergum 8 with four pairs of macrosetae; the distinct shape of aedeagus ( Figs. 139­148 ) and spermatheca ( Fig. 149 ).

Seeversiella mexicana can be distinguished from S. globicollis and the other similar species (3, 5­8, 11­12) with long elytra and weak pronotal microsculpture by the combination of the following characters: distal sclerites of internal sac poorly sclerotized, not dentiform or hook­shaped and have strong spicules ( Fig. 146 ); apex of median lobe in lateral view widened subapically and not emarginate on parameral side ( Figs. 141­142 ), in parameral view narrow and with weak basal constriction ( Figs. 139­140 ); spermatheca Sshaped with umbilicus facing proximally ( Fig. 149 ).

Description. Length 2.2­2.8 mm, pronotal width 0.41­0.53 mm. Body brown to dark brown with lighter elytra, legs brown to yellowish brown.

In all character states S. mexicana is very similar to S. globicollis , but differs in the shape of the aedeagus and spermatheca as described in the diagnosis.

In large males posterior angles of male tergum 3 projecting as spines up to twice as long as tergum 3 (measured medially), tergum 7 with medial carina along midline, the carina up to 2/3 as long as tergum length.

Aedeagus as in Figs. 139­148 .

Spermatheca as in Fig. 149 .

DS – distal sclerite of internal sac.

Distribution. Known from Mexico ( Fig. 387 ). Natural History. Seeversiella mexicana was collected in forest litter at altitude of 1700­2310 m.

Figures

FIGURE 387. Geographical distribution of Seeversiella from Mexico to Honduras.

FIGURES 135 ­ 138. Abdominal segment 8 of Seeversiella mexicana Gusarov, sp. n. (paratypes from Filo de Caballo (135 ­ 136) and Suchixtepec (137 ­ 138), Mexico). 135 – male tergum 8; 136 – male sternum 8; 137 – female tergum 8; 138 – female sternum 8. Scale bar 0.2 mm.

FIGURES 139 ­ 142. Aedeagus Seeversiella mexicana Gusarov, sp. n. (paratypes from Filo de Caballo, Mexico). 139 – median lobe, parameral view; 140 – apex of median lobe, parameral view; 141 – median lobe, lateral view; 142 – apex of median lobe, lateral view. Scale bar 0.2 mm (139, 141), 0.1 mm (140, 142).

FIGURES 143 ­ 149. Genitalia of Seeversiella mexicana Gusarov, sp. n. (paratypes from Filo de Caballo (143, 145 ­ 148) Suchixtepec (144, 149), Mexico). 143 – everted internal sac, parameral view; 144 – medial lamellae, parameral view; 145 ­ 146 – details of internal sac retracted into median lobe, lateral view; 147 – copulatory piece, lateral view; 148 – apex of left paramere; 149 – spermatheca. Scale bar 0.2 mm (143, 145 ­ 146), 0.1 mm (144, 147 ­ 149).