Tachyusa gracillima LeConte, 1863

Pa ṡnik, Grzegorz, 2006, A revision of the World species of the genus Tachyusa Erichson, 1837 (Coleoptera, Staphylinidae: Aleocharinae), Zootaxa 1146, pp. 1-152 : 50-53

Tachyusa gracillima LeConte, 1863 ( Figs. 33–35)

Tachyusa gracillima LeConte, 1863: 29 .

Tachyusa smithi Casey, 1906: 206 .

Tachyusa virginica Casey, 1911: 172 .

Tachyusa gracillima: Casey, 1906: 206 ; Klimaszewski, 1986: 61 (as valid species).

Tachyusa (s. str.) gracillima: Fenyes, 1920: 172 ; Bernhauer & Scheerpeltz, 1926: 585 (as

valid species).

Tachyusa (s. str.) smithi: Bernhauer & Scheerpeltz, 1926: 585 (as synonym of T. gracillima ). Tachyusa (s. str.) virginica: Bernhauer & Scheerpeltz, 1926: 585 (as synonym of T.

gracillima).

Type material. Tachyusa gracillima LeConte. Lectotype: ♂: T. gracillima Lec. , Type 6249 ( MCZ).

Tachyusa smithi Casey. Lectotype (here designated): ♂: New York, Catskill Mts. , type USNM 38941 ( USNM); Paralectotypes: 3♂♂ and ♀: New York, type USNM 38941 ( USNM).

Tachyusa virginica Casey. Holotype: ♀: Virginia, Fredericksburg , type USNM 38942 ( USNM).

Additional material. UNITED STATES. Arkansas: Franklin Co., Shores Lake, Ozark National Forest , 19.V.1986, J. M. Campbell, 3 exx ( CNC) ; Pulaski Co., Pinnacle Mt. State Park, Base Trail , 11.V.1986, J. M. Campbell, 2 exx ( CNC) ; Washington Co. , 2 mi W of Elkin, IX.1967, 2 exx ( AMNH) ; 1 ex ( ISEA). California: Applegate , 1 ex ( CAS) . Florida: Jaksonville , II.1937, 2 exx ( BMNH) ; 12–17.III.1937, 6 exx ( MCZ) ; 12– 17.III.1937, 1 ex ( FMNH) ; III.1937, 1 ex ( MNHN) ; Bierig , 3 exx ( FMNH) ; 25.VI.1988, 3 exx ( VAPC) . Georgia: Valdosta , 7.II.1948, L.D. Beamer, 1 ex ( SEMC) . Illinois: Cook Co., Palos Hills , 6.V.1984, L. E. Watrous, 2 exx ( FMNH) ; 6 exx ( MCZ); Cook Co., Skokie Harms Woods , 19.VI.1988, Ashe, 14 exx ( SEMC) ; Livingston Co., W of Cornell Wagner Farm , 25.VII.1967, 2 exx ( MCZ) ; PuPage Co., Palos Park , 15.VII.1945, along stream bank, 4 exx ( FMNH) ; Thornton , 19–20.VI.1944, Seevers, 9 exx ( FMNH) ; Union Co., 1 mi E Wolf Lake , 8.V.1976, Smetana, 3 exx ( CNC) ; Union Co., Pine Hills, near Pine Hills Campground , 7.V.1976, Smetana, 2 exx ( CNC) . Kansas: Douglas, 3.2 km N Baldwin, Breidenthal Reserve , 29.V.1996, M. Panaras, 1 ex ( SEMC) ; Douglas Co., 5 km S Lawrence , 31.V–6.VI.1985, R. W. Brooks, 2 exx ( SEMC) ; Douglas Co., 7.2 km S Lawrence , 12.V.1991, Ashe, 14 exx ( SEMC) ; 17.V.1992, Ashe, 10 exx ( SEMC) ; Douglas Breidenthal Nature Preserve , 270 m, 2.VIII.1997, Ashe, 1 ex ( SEMC) ; Leavenworth Co., VII.1933, Blackwelder, 2 exx ( AMNH) . Kentucky: Cumberland Co., Crocus Creek , 17.V.1969, T. E. Brooks, 12 exx ( SEMC) ; Sanborn , 1 ex ( MCZ) ; Trigg Co., Land Between The Lakes National Recreation Area, Devils Elbow , 6.V.1986, J.M. Campbell, 3 exx ( CNC) . Louisiana: Calcasieu Pa. , 4 mi W Starks, 19.IV.1976, Smetana, 40 exx ( CNC) ; 3 exx ( ISEA); Rapides Pa., Magnolia Recreation A, 12 mi SW Alexandria, 28.IV.1976, Smetana, 1 ex ( CNC) ; Rapides Pa., Magnolia Recreation Area , 15 mi SW Alexandria, 4.X.1973, A. Newton, 8 exx ( FMNH) . Maryland: Baltimore , VII.1910, F. E. Blaisdel, 3 exx ( CAS) ; VII.1912, 1 ex ( CAS) ; VII.1915, 2 exx ( CAS) ; VII.1916, 1 ex ( CAS) ; VII.1919, 1 ex ( CAS) . New Jersey: Ridgeway , 12.VI.1892, A. Bierig, 1 ex ( FMNH) . New York: Mosholu, 1 ex ( AMNH) . North Carolina: Rockingham Co., Reidsville , 27.IV.1979, Ashe, 1 ex ( SEMC) . Ohio: Hocking Co., 4 mi W Rockbridge , 8.V.1976, 2 exx ( MCZ) . Oklahoma: Latimer Co., IV.1988, Karl Stephan, 1 ex ( SEMC) ; VII.1988, 1 ex ( SEMC) ; Latimer Co., 5 mi W Red Oak , VIII.1986, Karl Stephan, 1 ex ( SEMC) . Pennsylvania: Bucks Co., 2 mi E Jamison , 5.VII.1969, J. & W. Ivie, 2 exx ( AMNH) ; Easton , 7 exx ( CAS) ; Lancaster Co., Kirkwood , 2.IX.1976, L. Watrous, 3 exx ( MCZ) . Texas: Brazos Co., College Station , 22.VI.1975, Ashe, 14 exx ( SEMC) ; Columbus , 1 ex ( FMNH) ; Houston Co., 11 mi E Ratcliff , 24.IV.1976, Smetana, 6 exx ( CNC) ; Montgomery Co., 17.2 km N Montgomery , 17.V–17.VI.1987, R. Anderson, 1 ex ( SEMC) . Virginia: Clarke Co., 3 mi E Berryville, Shenandoah River , 24.VII.1977, L. & N. Herman, 3 exx ( AMNH) ; 1 ex ( ISEA); Faugiers Co., 20 mi SSE Warrenton , 29.IV.1986, L. Herman, 2 exx ( AMNH) ; 1 ex ( ISEA); White Sulphur , 2 exx ( FMNH) .

Redescription. Body. Length 2.7–3.2 mm, convex, parallel­sided, glossy; body colour brownish red, abdomen black with two basal tergites red to brownish red, legs testaceous to brownish red, antennae brown with antennomeres 1–3 red.

Head circular in outline, convex, eyes large, moderately protruding from lateral contours of head, length of each seen from above subequal to that of postocular region; surface of head with fine isodiametric mesh microsculpture; puncturation fine and moderately dense. Antennae long, clearly increasing in width apically, antennomere 3 shorter than 2, antennomeres 4–8 longer than wide, antennomeres 9–10 quadrate, antennomere 11 nearly conical.

Pronotum quadrate, lateral sides gradually narrowed in straight line to obtuse hind angles; before base with moderately small and shallow transverse impression, broadly and shallowly impressed medially; surface without or with obsolete isodiametric mesh microsculpture; puncturation fine, dense and asperate; pubescence at midline directed posteriorly.

Elytra subquadrate, at suture slightly shorter than pronotal length at midline; surface lacking microsculpture; puncturation fine and moderately dense.

Abdomen parallel­sided, bases of tergites 3–5 each with deep transverse impression, impressions with 7–8 longitudinal ridges and distinct median carina, tergal puncturation fine and relatively scattered, punctures very small and weakly visible, tergite 7 with isodiametric mesh microsculpture.

Male. Aedeagus as in Figs. 33–34.

Female. Spermatheca as in Fig. 35.

Taxonomic notes. My comparison of the types, particularly the genitalia, showed that Tachyusa smithi Casey and Tachyusa virginica Casey are conspecific with Tachyusa gracillima LeConte and consequently a junior synonym of the latter.

Remarks. Tachyusa gracillima can be easily distinguished from the other Nearctic species by the very glossy body, the scattered abdominal puncturation, the distinct microsculpture of tergite 8 and by the shape of genitalia.

Distribution. Tachyusa gracillima is widespread in eastern United States.

The gemma group

The gemma group includes eight species restricted in distribution to Africa and the Oriental Region. The group is characterized by the following combination of characters: puncturation of tergites 3–5 very sparse, punctures minute, pinprick­like or invisible; puncturation of tergites 6–7 similar to that of tergites 3–5; tergal transverse impressions with longitudinal ridges connected by short transverse ridges in the shape of honeycomb; tergite 5 distinctly elongate, 1,30–1,40 times longer than tergite 4; pronotal pubescence very short and sparse; abdominal pubescence long, sparse and semierect; and abdomen strongly glossy.