Pachystilicus quadriceps ( LeConte, 1880 )

Żyła, Dagmara, Tokareva, Alexandra & Koszela, Katarzyna, 2022, Phylogenetic position of genera Acrostilicus Hubbard and Pachystilicus Casey (Staphylinidae, Paederinae) and their redescription, European Journal of Taxonomy 819 (1), pp. 1-22 : 12-13

Pachystilicus quadriceps ( LeConte, 1880)

Fig. 3

Stilicus quadriceps LeConte, 1880: 178 (original description, key, notes).

Pachystilicus quadriceps – Casey 1905: 227 (redescription). — Leng 1920: 104. — Lucas 1920: 475 (genotype fixed). — Blackwelder 1952: 285 (notes). — Moore & Legner 1979: 112. — Poole & Gentili 1996: 370. — Newton et al. 2001: 387 (comment on taxonomic status). — Bousquet et al. 2013: DwC-A database.

Diagnosis

Differs from P. hanhami by longer and denser setae covering body, longitudinal carina of basisternum more elevated. Additionally, median emargination of posterior margin of sternite VIII is deeper and broader than in P. hanhami , depth of emargination of ca ¼ of sternite length.

Type material

Lectotype (designated here) USA • ♂; “ Cal. / ♂ / Type 6584 / S. quadriceps Lec. / J.L. LeConte Collection ”; MCZ.

Additional studied material

CANADA – British Columbia • 1 spec.; “ Mts. Between Hope and Okanagan B. C. Sept. 90 / F C Bowditch Coll. / Stilicus quadriceps Lec ”; MCZ .

USA – California • 1 spec.; “Cala / Coll Hubbard and Schwarz / quadriceps Lec ”; NMNH . – Massachusetts • 1 spec.; “ Brookline Mass 4-14-88 / F. C. Bowditch Coll ”; MCZ .

Redescription

MEASUREMENTS. Body length: 5 mm; forebody length: 2.75–2.90 mm. COLOURATION. Dark brown to reddish brown; head darker, legs and antennae reddish brown ( Fig. 3A ).

HEAD. As in generic description (HL: 0.95–1.00 mm; HW: 1.0– 1.1 mm), with antennomere 1 elongate, widest at tip; antennomeres 2–4 elongate; antennomere 5 weakly elongate; antennomeres 6–10 gradually becoming transverse; antennomere 11 elongate, 1.5 × as long as antennomere 10.

THORAX. As in generic description (pronotal size: PL: 0.8–0.9 mm; PW: 0.8–0.9 mm; elytra size: EL: 1 mm; EW: 1.1–1.2 mm).

ABDOMEN. As in generic description; sternite VII with apical margin straight.

Distribution

The species has previously been recorded from the following US states: California, Massachusetts, and Missouri ( Newton 2018). We newly report this species from the Canadian province of British Columbia.

Figures

Fig. 3. Pachystilicus quadriceps (LeConte, 1880), habitus photograph and drawings of the apical abdominal sternite and genital structures. A. Habitus, lectotype, ♂ (MCZ). B. Male sternite VIII. C. Aedeagus, parameral view. D. Aedeagus, lateral view. Scale bar = 0.5 mm.