Stethusa spuriella ( Casey, 1910 )

Gusarov, Vladimir I., 2003, A revision of the Nearctic species of the genus Stethusa Casey, 1910 (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 239, pp. 1-43 : 25-28

Stethusa spuriella ( Casey, 1910)

( Figs. 58­70 )

Atheta (s. str.) unigranosa Bernhauer, 1909: 521 (nec Bernhauer, 1908: 363), syn. nov.

Atheta (Stethusa) spuriella Casey, 1910: 8 .

Atheta (Stethusa) subdebilis Casey, 1910: 7 , syn. nov.

Atheta (s. str.) duplicata Fenyes, 1920: 213 (replacement name for At. unigranosa Bernhauer, 1909 , nec 1908), syn. nov.

Atheta (Hypatheta) spuriella: Fenyes, 1920: 207 (as valid species).

Atheta (Hypatheta) subdebilis: Fenyes, 1920: 207 (as valid species).

Atheta macrops Notman, 1920: 725 , syn. nov.

Atheta (s. str.) unigranosa: Bernhauer & Scheerpeltz, 1926: 642 (as synonym of At. duplicata ).

Atheta (Hypatheta) spuriella: Bernhauer & Scheerpeltz, 1926: 654 (as valid species).

Atheta (Hypatheta) subdebilis: Bernhauer & Scheerpeltz, 1926: 654 (as valid species).

Atheta (s. str.) duplicata: Bernhauer & Scheerpeltz, 1926: 642 (as valid species).

Atheta (s. str.) macrops: Bernhauer & Scheerpeltz, 1926: 645 (as valid species).

Atheta (s. str.) duplicata: Moore & Legner, 1975: 360 (as valid species).

Atheta (s. str.) unigranosa: Moore & Legner, 1975: 360 (as synonym of At. duplicata ).

Atheta (Stethusa) spuriella: Moore & Legner, 1975: 374 (as valid species).

Atheta (Stethusa) subdebilis: Moore & Legner, 1975: 374 (as valid species).

Xenota unigranosa: Seevers, 1978: 269 (as valid species).

Xenota duplicata: Seevers, 1978: 269 (as synonym of At. unigranosa ).

Xenota spuriella: Seevers, 1978: 269 (as valid species).

Xenota subdebilis: Seevers, 1978: 269 (as valid species).

Microdota macrops: Seevers, 1978: 265 (as valid species).

Type material. Lectotype of Atheta unigranosa (here designated): ɗ, "Newark, Del. [aware], 5­22.1905 [22.v.1905]", "7803", "Houghton", " unigranosa Bernh. Typus. Fenyes" (yellow label), "Chicago NHMus. M.Bernhauer Collection ( FMNH).

Lectotype of Atheta spuriella (here designated): ɗ, "N. Y. [New York, Catskill Mountains]", " spuriella Csy. ", " TYPE USNM 39439" (red label), " CASEY bequest 1925" ( NMNH).

Lectotype of Atheta subdebilis (here designated): ɗ (with missing aedeagus), "MO: [Missouri, St. Louis]", " subdebilis Csy. ", " TYPE USNM 39446" (red label), " CASEY bequest 1925" ( NMNH). Paralectotype: Ψ, "MO: [Missouri, St.Louis]", " subdebilis PARATYPE USNM 39446" (red label), " CASEY bequest 1925" ( NMNH).

Paratypes of Atheta macrops : UNITED STATES: Florida: 2ΨΨ, "Fla." (no locality data) ( AMNH, FMNH); Jefferson Co.: Ψ, Monticello, 4­8.x.1914 ( AMNH).

Additional material. UNITED STATES: Pennsylvania: Westmoreland Co.: ɗ, Jeannette (H.G.Klages) ( FMNH); Ohio: ɗ, without locality data (Frost) ( CASC); Indiana: Lawrence Co.: 2ɗɗ (W.S.Blatchley), 29.vii.1909 ( CASC); Georgia: Rabun Co.: 2ɗɗ, Clayton, 2000­3700' (Leng) ( CASC).

Diagnosis. Stethusa spuriella differs from S. dichroa in the following characters: a smaller body size; the lack of subbasal impressions of the terminal antennal article; the lack of the distal spines of the internal sac ( Figs. 68 ; 38­39); the shape of the spermatheca ( Figs. 70 ; 41­42); and the lack of a female accessory sclerite.

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

Description. Length 2.1­2.5 mm. Head and abdomen dark brown, abdominal segments 3­4 and apical half of segment 7 lighter, pronotum brown, elytra brownish yellow, in some with darker area around scutellum, legs yellow, mouthparts and antennae brown, two basal antennal segments yellow.

Head surface glossy, with weak isodiametric microsculpture, with fine punctation, distance between punctures equals 3 times their diameter. Eyes very large, 3.5­4.5 times as long as temples. Antennal article 2 is 1.1 times as long as article 3, articles 4­10 transverse, article 11 slightly longer than articles 9 and 10 combined.

Pronotum transverse, 1.2 times as wide as head, width 0.46­0.57 mm, length 0.36­0.44 mm, width to length ratio 1.3; glossy, with very weak isodiametric microsculpture (hardly visible at 70x); punctation as fine as on head but denser, distance between punctures equal to 1­2 times their diameter. Elytra much wider (0.59­0.73 mm) and longer (0.43­0.57 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 (at 70x) microsculpture; punctation as on pronotum, slightly asperate.

Abdominal terga glossy, with weak microsculpture consisting of transverse waves; with fine punctation, distance between punctures equals 2­4 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 weak elongate medial tubercle in front of posterior margin. Posterior margin of male tergum 8 with two blunt medial projections and two lateral denticles ( Figs. 58, 60 ).

Aedeagus as in Figs. 63­69 , internal sac without distal spines ( Fig. 68 ).

Female without accessory sclerite. Spermatheca as in Fig. 70 .

Discussion. The three species synonymized here with S. spuriella are identical with the types of that species in external characters and the shape of the aedeagus. Distribution. Apparently, S. spuriella is widely distributed in the eastern United States but its distribution is poorly documented ( 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 58 ­ 62. Abdominal segment 8 of Stethusa spuriella (Casey) (male, 18 km SSE Lawrence, Kansas (58 ­ 60); and female 9 km W Buffalo Gap, Virginia (61 ­ 62 )). 58 – male tergum 8; 59 – male sternum 8; 60 – apex of male tergum 8; 61 – female tergum 8; 62 – female sternum 8. Scale bar 0.2 mm (58 ­ 59, 61 ­ 62), 0.1 mm (60).

FIGURES 63 ­ 70. Aedeagus and spermatheca of Stethusa spuriella (Casey) (male, 18 km SSE Lawrence, Kansas (63 ­ 69); and female 9 km W Buffalo Gap, Virginia (70 )). 63 – median lobe, parameral view; 64 – apex of median lobe, parameral view; 65 – median lobe, lateral view; 66 – apex of median lobe, lateral view; 67 – details of retracted internal sac, abparameral view; 68 – details of retracted internal sac, lateral view; 69 – apex of left paramere; 70 – spermatheca. Scale bar 0.1 mm (64, 66, 69 ­ 70), 0.2 mm (63, 65, 67 ­ 68).