Stethusa klimschi ( Bernhauer, 1909 )

Gusarov, Vladimir I., 2003, A revision of the Nearctic species of the genus Stethusa Casey, 1910 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 239, pp. 1-43 : 21-25

Stethusa klimschi ( Bernhauer, 1909)

( Figs. 21 , 43­57 )

Atheta (s. str.) klimschi Bernhauer, 1909: 523 .

Atheta (Stethusa) klimschi: Casey, 1910: 5 (as valid species).

Atheta sulcata Blatchley, 1910: 355 .

Atheta (Hypatheta) klimschi: Fenyes, 1920: 207 (as valid species). Atheta sulcata: Fenyes, 1920: 227 (as valid species of doubtful systematic position). Atheta (Hypatheta) klimschi: Bernhauer & Scheerpeltz, 1926: 653 (as valid species). Atheta (Earota) sulcata: Bernhauer & Scheerpeltz, 1926: 655 (as valid species). Atheta (Stethusa) klimschi: Moore & Legner, 1975: 364 (as valid species). Atheta (Earota) sulcata: Moore & Legner, 1975: 375 (as valid species). Stethusa klimschi: Seevers, 1978: 267 (as valid species).

Earota sulcata: Seevers, 1978: 271 (as valid species).

Atheta klimschi: Gusarov, 2002b: 14 (as valid species).

Atheta sulcata: Gusarov, 2002b: 14 (as synonym of At. klimschi ).

Type material. Lectotype of Atheta klimschi (designated by Gusarov (2002b)), UNITED STATES: Louisiana: St. Landry Parish: ɗ, Opelousas, vi; paralectotype of Atheta klimschi , UNITED STATES: Louisiana: ɗ, Opelousas, vi ( FMNH).

Lectotype of Atheta sulcata (designated by Gusarov (2002b)), UNITED STATES: Indiana: Posey Co.: ɗ, 22.iv.1909 ( PURC).

Additional material. United States: Louisiana: St. Landry Parish: 2ɗɗ, Opelousas, v (Klimsch) ( FMNH); Mississippi: Warren Co.: 2ɗɗ, 3ΨΨ, "·Miss." [Vicksburg (according to Casey locality Code (FitzGerald 1962))] ( NMNH (Casey collection)).

Diagnosis. Stethusa klimschi differs from S. dichroa in the following characters: the lack of subbasal impressions of the terminal antennal article; the apex of median lobe is narrower in ventral view ( Figs. 48­49 ; 29­30) and straight in lateral view ( Figs. 50­51 ; 31­ 32); the lack of the distal spines of the internal sac ( Figs. 54 ; 38­39); the shape of the spermatheca ( Figs. 57 ; 41­42); and the lack of a female accessory sclerite.

Stethusa klimschi differs from S. spuriella in having a larger body size; straight apex of the median lobe (in lateral view; Figs. 50­51 ; 65­66); and a longer spermatheca ( Figs. 57 ; 70).

Description. Length 3.2­3.5 mm. Head dark brown, pronotum and abdomen reddish brown to brown, segments 5­6 darker than the rest of the abdomen; elytra brownish yellow with darker area around scutellum and epipleura, legs brownish yellow, mouthparts and antennae brown, two basal antennal segments yellowish.

Head surface glossy, with weak isodiametric microsculpture, with fine punctation, distance between punctures equals 2 times their diameter. Eyes very large, 3.5­5 times as long as temples. Antennal article 2 is 1.1 times as long as article 3, articles 4­6 subquadrate, 7­10 slightly transverse, article 11 as long as articles 9 and 10 combined.

Pronotum transverse, 1.3 times as wide as head, width 0.69­0.77 mm, length 0.54­0.61 mm, width to length ratio 1.3; glossy, with weak isodiametric microsculpture; punctation as fine as on head but denser, distance between punctures equal to 1­2 times their diameter. Elytra much wider (0.86­0.96 mm) and longer (0.67­0.74 mm; measured from humeral angle) than pronotum (elytral length to pronotal length ratio 1.2), 1.3 times wider than long, surface glossy, with poorly visible microsculpture; punctation fine and slightly asperate, distance between punctures equals 1­2 times their diameter.

Abdominal terga glossy, with weak microsculpture consisting of transverse waves; with fine punctation, distance between punctures equals 1­3 times their diameter on terga 3­5 and 3­6 times on terga 6­7. Apical margin of tergum 7 with white palisade fringe.

Male tergum 7 with elongate medial tubercle in front of posterior margin. Posterior margin of male tergum 8 with two blunt medial projections and two lateral denticles ( Figs. 43, 45 ).

Aedeagus as in Figs. 48­56 , internal sac without distal spines ( Fig. 54 ).

Female without accessory sclerite. Spermatheca as in Fig. 57 .

Discussion. In my earlier paper ( Gusarov 2002b) I argued that S. klimschi did not belong to Earota because of the narrower mesosternal process, and tentatively placed this species in Atheta . Although in S. klimschi the mesosternal process is indeed narrower than in Earota it is still broader than in Atheta . Stethusa klimschi can be distinguished from Atheta based on additional characters listed in the diagnosis of Stethusa .

Distribution. Stethusa klimschi is known from Louisiana, Mississippi and southern Indiana ( Fig. 111 ).

Natural History. No information is available.

Figures

FIGURE 111. Geographical distribution of Stethusa klimschi (Bernhauer) and S. spuriella (Casey). The exact locality in Ohio is unknown.

FIGURES 18 ­ 21. Details of Stethusa dichroa (Gravenhorst) (male (18) and female (19), Eddyville, Illinois), S. spuriella (Casey) (male, 18 km SSE Lawrence, Kansas (20 )), and S. klimschi (Bernhauer) (male, Opelousas, Louisiana (21 )). 18 – pronotum; 19 ­ 21 – meso­ and metathorax, ventral view. Scale bar 0.4 mm.

FIGURES 43 ­ 47. Abdominal segment 8 of Stethusa klimschi (Bernhauer) (male (43 ­ 45) and female (46 ­ 47) from Vicksburg, Mississippi). 43 – male tergum 8; 44 – male sternum 8; 45 – apex of male tergum 8; 46 – female tergum 8; 47 – female sternum 8. Scale bar 0.4 mm (43 ­ 44, 46 ­ 47), 0.2 mm (45).

FIGURES 48 ­ 52. Aedeagus of Stethusa klimschi (Bernhauer) (lectotype (48 ­ 51); and male from Vicksburg, Mississippi (52 )). 48 – median lobe, parameral view; 49 – apex of median lobe, parameral view; 50 – median lobe, lateral view; 51 – apex of median lobe, lateral view; 52 – apex of left paramere. Scale bar 0.1 mm (49, 51 ­ 52), 0.2 mm (48, 50).

FIGURES 53 ­ 57. Aedeagus and spermatheca of Stethusa klimschi (Bernhauer) (lectotype (53 ­ 54); male (55 ­ 56) and female (57) from Vicksburg, Mississippi). 53 – details of retracted internal sac, abparameral view; 54 – details of retracted internal sac, lateral view; 55 – copulatory piece, lateral view; 56 – copulatory piece, abparameral view; 57 – spermatheca. Scale bar 0.2 mm (53 ­ 54), 0.1 mm (55 ­ 57).