Atomaria pusilla (Paykull, 1798)

Majka, Christopher, Johnson, Colin & Langor, David, 2010, Contributions towards an understanding of the Atomariinae (Coleoptera, Cryptophagidae) of Atlantic Canada, ZooKeys 35 (35), pp. 37-63 : 54

Atomaria pusilla (Paykull, 1798)

NOVA SCOTIA: Cumberland Co.: Wentworth Park , July 12, 1993, J. & T. Cook, car net (2, JCC) ; Yarmouth Co.: Carleton: Perry Rd. , July 18, 1993, J. & T. Cook, car net (1, JCC) ; Coldstream Rd. E of Quinan, July 19, 1993, J. & T. Cook, car net (2, JCC). NEW BRUNSWICK: Albert Co.: Mary’s Pt. , August 9, 2002, C.G. Majka, coniferous forest, decaying Russula virescens (1, CGMC) ; Westmorland Co.: Shediac , September 30, 1972 (1, MMUE) .

Atomaria pusilla is newly recorded in New Brunswick and Nova Scotia (Fig. 15). In North America it has been recorded in Alaska, British Columbia, Connecticut, Idaho, Indiana, New York, Ohio, Oregon, Québec, and Washington ( Blatchley 1910; Britton 1920; Notman 1920; Hatch 1961; Bousquet 1991; Williams et al. 1995; Downie and Arnett 1996). Blatchley (1910) referred to it as a “European” species and Bousquet (1991) listed it as “probably introduced” in North America. In the Palaearctic region it is found throughout Europe (including Turkey), across North Africa, and in central Asia in Iran, Afghanistan, and Kazhakhstan, northeast to Mongolia and the Russian Far East ( Johnson et al. 2007). Blatchley (1910) reported it from the borders of a sphagnum marsh and in other damp vegetable debris. In New Brunswick it was found in a coniferous forest on a decaying gill fungus. Johnson (1993) reported that it was, “a grassland species which is found especially around farms and gardens and only rarely elsewhere, It has been collected in man-made heaps of refuse, cut vegetation, hay, grass, and compost heaps.

Description: Body (dorsally and ventrally) uniformly reddish-yellow. Antennae and legs uniformly yellow-colored. Head very finely and sparsely punctate. Pronotum widest at midpoint, constricted basally and apically. Pronotum moderately finely and closely punctate, interspaces 1.0 times the diameter of punctures; pronotal base with a complete fine marginal line running along the bottom of the basal impression. Elytral punctation similar to pronotum (Fig. 8). Antennae: antennomere 1 short, straight, not or slightly expanded at apex, slightly longer than wide, approximately as long as antennomere 2; 3 slightly shorter than 2; 4–8 short and bead-like; antennal club distinct; antennomeres 9 and 10 transverse (Fig. 1.8). The smallest species of the genus; body width/length ratio, 0.40; length, 1.0–1.2 mm.