Tachyusa ornatella Casey, 1906

Pa ṡnik, Grzegorz, 2006, A revision of the World species of the genus Tachyusa Erichson, 1837 (Coleoptera, Staphylinidae: Aleocharinae), Zootaxa 1146, pp. 1-152 : 49-50

Tachyusa ornatella Casey, 1906 ( Fig. 32)

Tachyusa ornatella Casey, 1906: 211 .

Tachyusa (s. str.) ornatella: Fenyes, 1920: 173 ; Bernhauer & Scheerpeltz, 1926: 585.

Type material. Holotype: ♀: Texas, Del Rio, July 23–24, 955 ft., H. F. Wickham, type USNM 38955 ( USNM).

Redescription. Body. Length 2.7 mm, convex, parallel­sided, glossy; head brownish red, pronotum reddish­brown, elytra yellowish brown with posterior margin yellow, abdomen black with two basal tergites red, legs and antennae yellowish red.

Head circular in outline, convex, eyes moderately large, weakly protruding from lateral contours of head, length of each seen from above subequal to that of postocular region; surface of head without microsculpture; puncturation fine and scattered. Antennae short, clearly increasing in width apically, antennomere 3 shorter than 2, antennomeres 4– 6 longer than wide, antennomeres 7–8 quadrate, antennomeres 9–10 slightly transverse, antennomere 11 nearly conical.

Pronotum slightly transverse, lateral sides gradually narrowed in straight line to obtuse hind angles; before base with small and shallow transverse impression; surface without microsculpture; puncturation very fine, relatively scattered and weakly asperate; pubescence at midline directed posteriorly.

Elytra subquadrate, at suture as long as pronotal length at midline; surface lacking microsculpture; puncturation fine, dense and weakly 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 scattered, punctures very small and scarcely visible, surface without microsculpture.

Female. Spermatheca as in Fig. 32.

Male unknown.

Remarks. Tachyusa ornatella is similar to T. gracillima LeConte, 1863 , from which it differs by the paler body colour, the transverse pronotum, the finer and sparser puncturation of head and pronotum, the less convex pronotum and by the tergite 8 without microsculpture.

Distribution. The species is known so far only from its type locality in Texas.