Tachyusa americanoides Pa, 2006

Pa ṡnik, Grzegorz, 2006, A revision of the World species of the genus Tachyusa Erichson, 1837 (Coleoptera, Staphylinidae: Aleocharinae), Zootaxa 1146, pp. 1-152 : 137-139

Tachyusa americanoides Pa ś nik, sp. n. ( Figs. 141–143)

Type material. Holotype: ♂: [ Canada], N.W.T. [Northwest Territories], Hwy 10 mi SE Fort Simpson , 18.VI.72, A. Smetana ( CNC) ; Paratypes: ♂: [ Canada], 5 mi SW Shilo, Man. [Manitoba], 16.VI.1958, R. B. Madge ( CNC) ; ♂: [ Canada], St. Lawrence Is. Nat. Park, Ont., Grenadier Is. W., 27.VI.1975, A. Dawies ( CNC) ; ♀: [ Canada], St. Lawrence Is. Nat. Park, Ont., Grenadier I. Centre , 27.VI.1975, J. M. Campbell ( ISEA) ; 2♀♀: [ Canada], B.C. [British Columbia], 8 mi W Creston , 10.VI.1968, Campbell & Smetana ( CNC) ; 2♀♀: [ Canada], Man. [Manitoba], Spruce Woods Prov. Pk., Assiniboine River , 2–19.VI.1973, J. Redner & C. Starr ( CNC) ; ♀: [ Canada], St. Lawrence Is. Nat. Park, Ontario, Grenadier I. Centre , 26.VI.1975, A. Smetana ( CNC) ; ♀: [ Canada], Ontario, Ottawa, Brittaria Bay , 16.VI.1978, D. Maddison ( CNC) ; ♀: [ Canada], Nova Scotia, Halifax , Sackville, 20.V.51, Lindroth ( CNC) ; ♀: [ Canada], Gananoque , Ontario, 24.V.1976, Kiteley ( CNC) ; ♀: [ Canada], Wakelield , Quebec, 4.VI.1930, W.J. Brown ( CNC) ; ♀: Alta., Bruderheim , 1.VII.1982, A. Davies ( ISEA) ; ♂: Mont., Basin , 7.VII.1976, J.M. Campbell ( ISEA) ; ♂: [ United States], Frmghm., Mass., Frost ( CAS) ; 2♂♂ and ♀ [ United States], Mt. Pocono , 4.VI.1933, Pa., J.W. Green ( CAS) ; ♂: [ United States], Lk. Placid , 25.VII.1936, N.Y., Green ( CAS) ; ♂: [ United States], Wind Gap , 25.VI.1932, J.W. Green ( CAS) ; ♀: [ United States], Deer Creek, Can, Col. , 13.VII.1938, Green ( CAS) ; ♀: [ United States], Squam Lk. , 10.VII.1937, NH., J.W. Green ( CAS) ; ♂: [ United States], West Sprgs. , Illinois, 26.VI.1944, H. Dybas ( FMNH) ; ♂: [ United States], Royalton , Vermont, 3.VI.1985, G.J. Kiteley ( CNC) .

Description. Body. Length 2.7–3.2 mm, convex, parallel­sided, glossy; body colour pitchy brown to black; abdomen black with three basal tergites reddish brown, legs reddish brown, antennae brown with antennomeres 1–3 red.

Head circular in outline, convex, glossy, narrower than pronotum, widest across eyes; eyes relatively small, moderately protruding from lateral contours of head, length of each seen from above slightly shorter than postocular region; surface of head without microsculpture; puncturation fine and moderately dense; pubescence short and moderately dense, directed inward. Antennae short, clearly increasing in width apically, antennomeres 2 and 3 subequal in length, antennomeres 4–7 longer than wide, antennomeres 8–10 sexually dimorphic, quadrate in male and slightly transverse in female, antennomere 11 nearly conical.

Pronotum quadrate, convex, glossy, widest in apical third, lateral sides rounded in front, gradually narrowed in straight line to obtuse hind angles; before base with small and shallow transverse impression; surface lacking microsculpture; puncturation fine, dense and asperate; pubescence at midline directed posteriorly.

Elytra longer than wide, slightly wider than pronotum, lateral sides arcuate, at suture as long as pronotal length at midline; surface lacking microsculpture; puncturation fine, dense and asperate.

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 moderately dense, punctures moderately small and well visible, surface without microsculpture.

Male. Aedeagus as in Figs. 141–142.

Female. Spermatheca as in Fig. 143.

Remarks. Externally, T. americanoides is extremely similar to T. americana Casey,

1906, but differs in the following characters: the antennomeres 2 and 3 subequal in length; the elytra longer than wide; elytral length at suture as long as pronotal length at midline; and particularly the distinct shape of the aedeagus.

Etymology. The name refers to the habitus similar to that of T. americana .

Distribution. Tachyusa americanoides is known so far from several localities in Canada and United States.