Taxon classification Animalia Coleoptera Staphylinidae

Atheta (Datomicra) nigra (Kraatz) Figs 9-15

Diagnosis .

Body narrowly elongate (Fig. 9), length 1.8-2.3 mm, dark brown to black, legs with at least tarsi reddish-brown; head, pronotum and elytra finely and densely punctate, punctures small; pubescence dense; integument strongly glossy; pronotum transverse, slightly narrower than elytra, with median line of disc well defined, pubescence directed laterad from median line; elytra at suture slightly longer than pronotum; abdomen subparallel. MALE. Median lobe of aedeagus with oval bulbus and narrowly elongate and pointed tubus in ventral view (Fig. 11), in lateral view tubus slightly sinuate and slightly pointed ventrally at apex (Fig. 10); internal sac structures not pronounced; tergite VIII with four small dents apically (Fig. 12); sternite VIII broadly rounded apically. FEMALE. Tergite VIII truncate and slightly concave apically (Fig. 14); sternite VIII broadly arcuate apically with shallow apical emargination (Fig. 15); spermatheca with narrowly elongate and angularly bent capsule bearing large and long apical invagination, stem narrow, and with a single posterior coil bearing swollen apical part (Fig. 13).

Distribution.

Natural history.

The single female in Saskatchewan was captured in horse manure in September.

Remarks.

This species is similar to our native Atheta (Datomicra) acadiensis Klimaszewski & Majka (2007) described from Nova Scotia but it is readily distinguishable by the morphology of genital structures. For illustrations of Atheta acadiensis, see Klimaszewski and Majka (2007).