Acrotona avia ( Casey, 1910 )

Majka, Christopher, Klimaszewski, Jan & Lauff, Randolph, 2008, The coastal rove beetles (Coleoptera, Staphylinidae) of Atlantic Canada: a survey and new records, ZooKeys 2 (2), pp. 115-150 : 123

Acrotona avia ( Casey, 1910)

NOVA SCOTIA: Antigonish Co.: Pomquet Beach , IV.1996, R.F. Lauff, sand dunes, leaf litter, (1 female; 1 male, NSMC) .

Acrotona avia ( Fig. 1 ) is newly recorded in Canada ( Fig. 12 ). Acrotona avia was described by Casey (1910) on the basis of specimens collected in Rhode Island. The bionomics of the species are unknown, however, it appears that A. avia could be associated with sandy, seacoast environments. Pomquet Beach (45°39’27”N, 61°49’18”W) is a coastal barrier beach that lies between Pomquet Harbour and St. Georges Bay on the Gulf of St. Lawrence in Nova Scotia. The specimens from that locale were collected in a coastal sand dune environment adjacent to a “slack” (a temporary water body lying between two dune crests). Saunderstown (Rhode Island) is located near the mouth of Narragansett Bay where it opens up onto Long Island Sound. The Casey family farm (41°30’44”N, 71°25’23”W), where T.L. Casey lived and carried out collecting ( Sikes 2004), is located 0.35 km from the seacoast, immediately adjacent to a barrier beach and coastal lagoon environment very similar to the Pomquet Beach site in Nova Scotia. Although there is no specific information that Casey collected the type specimens from precisely this site, it appears probable that A. avia is associated with such coastal environments. Cercyon litoralis (Gyllenhal, 1808) [ Hydrophilidae ] and Stenus erythropus Melsheimer, 1844 [ Staphylinidae ] were collected together with A. avia at Pomquet Beach.

Until this present report from Nova Scotia the species has not otherwise been reported from outside Rhode Island. It is likely that it is not as restricted in distribution as these limited records would appear to indicate, but rather as Sikes (2004: 10) pointed out, “…even in well-studied, temperate regions, a great deal of basic taxonomic work remains to be done”.

Gusarov (2001 -2003) listed this name as a junior synonym of Acrotona subpygmaea Bernhauer, 1909 . However, we have specimens at hand from New Brunswick (see Klimaszewski et al. 2005: 14, 15, 34) examined by him and identified as A. subpygmaea Bernhauer , which clearly belong to a different species. For this reason we provisionally retain A. avia as a distinct species until proper revisionary studies are finalized. We confirm however, that A. puritana ( Casey, 1910) [originally Colpodota ] is a junior synonym of A. avia (Casey) . We were able to examine four syntypes of A. avia from Rhode Island, Boston Neck, housed in the Casey collection in Washington (USNM). We designate here the female bearing the following labels as the lectotype: “R.I., a via -3, paralectotype USNM, 38993, Casey bequest 1925”, and Gusarov’s unpublished paralectotype label: “ paralectotypus, Colpodota avia Casey , female, V.I. Gusarov des. 2000” (USNM) [genital structures well preserved]. The remaining three specimens then become paralectotypes: R.I., Casey bequest 1925, avia -2, paratype USNM 38993, paralectotypus, Colpodota avia Casey , male, V.I. Gusarov des. 2000 (USNM) male [aedeagus missing in the attached vial]; R.I. same labels as the lectotype except, avia -1, Type USNM 387993, Gusarov’s unpublished lectotype designation label 2000 (USNM) 1 female; and R.I., avia -4 (USNM) 1 female. We have designated a female specimen as a lectotype because the female of this species may be easily distinguished by having the apical margin of sternite eight deeply emarginate ( Fig. 11 ) and by the shape of the spermatheca ( Fig. 9 ), and because the male genital structures were missing in the only male specimen in the type series. To avoid potential confusion in identification of this species in the future we provide for the first time the images of the body and the genital structures ( Figs. 1 , 5-11 ). The body and the genital structures of A. subpygmaea (Bernhauer) are published in Figs. 25, 116-119 in Klimaszewski et al. (2005), based on V.I. Gusarov’s identification.

Figures

Figs 1-4. Dorsal habitus: Fig. 1, Acrotona avia; Fig. 2, Oligota parva; Fig. 3, Strigota ambigua; Fig. 4, Myrmecopora vaga.

Fig. 12. The distribution of Micralymma marinum, Aleochara litoralis, Oligota parva, Acrotona avia, and Strigota ambigua in Atlantic Canada.

Figs 5-11. Genital structures of Acrotona avia: 5-8 male: Fig. 5, median lobe of aedeagus in dorsal view, and Fig. 6 in lateral view; Fig. 7, tergite VIII, and Fig. 8 sternite VIII; figures 9-11 female: Fig. 9, spermatheca; Fig. 10, tergite VIII; Fig. 11, sternite VIII.