Atheta (Microdota) pseudopittionii 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 : 58-59

Taxon classification Animalia Coleoptera Staphylinidae

Atheta (Microdota) pseudopittionii Klimaszewski & Larson sp. n. Figs 21-28

Holotype (male).

Canada, Saskatchewan, Larson Ranch, Hwy 21, 16 km S Maple Creek, 7-IX-2010, ex Lepiota rhacodes , D. Larson (LFC). Paratypes. Canada, Saskatchewan, Larson Ranch, Hwy 21, 16 km S Maple Creek: 25-VI-2008, carrion trap, D. Larson (CNC) 1 male, 1 female; 8-VII-2013, mushrooms, D. Larson (CNC, LFC) 1 male, 3 females; 15-VII-2014, decaying polypore mushroom, D. Larson (DLC, LFC) 2 females; 6-VIII-2013, ex Lepiota rhacodes , D. Larson (DLC, LFC) 3 males; 7-IX-2010, ex Lepiota rhacodes , D. Larson (DLC) 1 male, 2 females.

Etymology.

The species name pseudopittionii derived from the prefix pseudo- (false) and the specific name of European species Atheta pittionii Scheerpeltz, to which it is similar externally and has similar genitalia.

Diagnosis.

Body narrowly subparallel (Fig. 21), length 1.9-2.0 mm, uniformly black with tarsi yellowish; head, pronotum and elytra finely and sparsely punctate and pubescent, punctures small; integument strongly glossy, more so on abdomen, with meshed microsculpture; pronotum transverse, distinctly narrower than elytra, with pubescence directed obliquely anteriad anteriorly and obliquely posteriad posteriorly from median line of disc (Fig. 21); elytra at suture distinctly longer than pronotum (Fig. 21); abdomen subparallel. MALE. Tergite VIII truncate apically and slightly emarginate (Fig. 24); sternite VIII rounded apically (Fig. 25). Median lobe of aedeagus with large oval bulbus, and short and broadly triangular tubus in dorsal view (Fig. 23), in lateral view tubus arcuate with base near bulbus sinuate (Fig. 22); internal sac structures as illustrated (Figs 22, 23). FEMALE. Tergite VIII truncate apically (Fig. 26); sternite VIII broadly arcuate apically (Fig. 27); spermatheca with spherical capsule bearing narrow apical invagination, stem narrow, and with a small coiled apex (Fig. 28).

This species is very similar to European Atheta pittionii Scheerpeltz, from which it differs by broader and more elongate elytra, larger bulbus of median lobe of aedeagus in dorsal view (Fig. 23), more sinuate base of tubus of median lobe of aedeagus in lateral view (Fig. 22), and differently shaped complex structures of the internal sac (Figs 22, 23). For genitalia of Atheta pittionii , see Brundin (1948) [under the name of Atheta parvicornis ].

Distribution.

Adults are known only from SK.

Natural history.

Most adults of this species were collected from Shaggy parasol mushrooms, Chlorophyllum rhacodes (= Lepiota rhacodes ), from unspecified mushrooms, and from carrion.