Acrotona pseudopygmaea Klimaszewski & Larson

Klimaszewski, Jan, Larson, David J., Labrecque, Myriam & Bourdon, Caroline, 2016, Twelve new species and fifty-three new provincial distribution records of Aleocharinae rove beetles of Saskatchewan, Canada (Coleoptera, Staphylinidae), ZooKeys 610, pp. 45-112 : 53-54

Taxon classification Animalia Coleoptera Staphylinidae

Acrotona pseudopygmaea Klimaszewski & Larson sp. n. Figs 8-15

Holotype (male).

Canada, Saskatchewan, Larson Ranch, Hwy 21, 16 km S Maple Creek, 24-VII-2010, sifted from old mouldy alfalfa hay, D. Larson (LFC). Paratypes. 1 male and 1 female, with same label and collection data as the holotype (CNC).

Etymology.

The name of this species derives from the Latin participle pygmaea -, meaning small, and the prefix pseudo-, false. The genital structures of this species are similar to those of Palaearctic Acrotona pygmaea (Gravenhorst).

Diagnosis.

Body narrowly elongate, moderately convex, uniformly dark brown to almost black except for paler legs (Fig. 8); punctation on forebody fine, dense and asperate on elytra; head narrower than pronotum, ratio of maximum width of head to maximum width of pronotum 0.6; pronotum moderately transverse, ratio of maximum width to length 1.4, about as wide as elytra (Fig. 8); elytra at suture about as long as pronotum (Fig. 8); abdomen slightly narrowed posteriad; body length 2.4 mm; antennal articles V-X subquadrate. MALE. Tergite VIII moderately elongate and truncate apically (Fig. 11); sternite VIII rounded apically (Fig. 12); median lobe of aedeagus broad and rounded apically in dorsal view (Fig. 10), and tubus straight with apex facing upward in lateral view (Fig. 9). FEMALE. Tergite VIII truncate and slightly concave apically (Fig. 13); sternite VIII slightly emarginate apically (Fig. 14); spermatheca with tubular capsule and long, thin and sinuate posteriorly stem (Fig. 15).

Distinguished from all other Acrotona by the shape of median lobe of aedeagus with apex turned dorsally in lateral view (Fig. 9), by the shape of spermatheca with thin, long, sinuate, and posteriorly looped stem (Fig. 15), and by the shape of tergite and sternite VIII, which have basal margin straight and not sinuate (Figs 11-14).

Distribution.

This species is known only from the type locality in SK.

Natural history.

The type specimens were sifted from old mouldy alfalfa hay.

Comments.

This species is similar to Palaearctic Acrotona pygmaea (Gravenhorst) from which it differs by subquadrate antennal articles VI-X, by apex of tubus of median lobe of aedeagus more angular, female sternite VIII emarginated apically and spermatheca with much longer and broadly looped stem. It is also genitally similar to Nearctic Acrotona actuella (Casey) and Acrotona egregiella (Casey), from which it differs by straight and not sinuate ventral margin of tubus of median lobe of aedeagus, by straight and not sinuate basal margin of male tergite VIII, and by differently shaped spermatheca with posterior loop of stem sinuate.