Atheta (Datomicra) celata (Erichson)

Majka, Christopher G., Klimaszewski, Jan & Lauff, Randolph F., 2006, New Coleoptera records from owl nests in Nova Scotia, Canada, Zootaxa 1194, pp. 33-47 : 37-42

Atheta (Datomicra) celata (Erichson) [= Datomicra wrangeli Casey, 1911 . syn nov.]

These specimens represent the first North American report of this apparently Palearctic species ( Figures 1­5 ). It is widely distributed throughout Europe, east throughout eastern and western Siberia, and south to the North African coast ( Löbl and Smetana, 2004). In Europe it is known to inhabit the nests of mammals and birds ( Bickhardt 1907, Heinemann 1910, Strand 1967).

The distribution and status of A. celata clearly warrants further investigation to determine the extent of its distribution in Canada and to shed light on whether it is an adventive Palearctic or a Holarctic species (see below). It is noteworthy that the species was found in both a boreal owl nest on the Cheticamp River in the central Cape Breton highlands and in a northern saw­whet owl nest at Donnelly's Lake in Guysborough County on the mainland of Nova Scotia: two different host species at sites that are circa 130 kilometers apart. This suggests that this species may be widely distributed in Nova Scotia in suitable situations.

Casey (1910) described Datomicra wrangeli from Fort Wrangel, Alaska. The second author examined two syntypes of Casey’s specimens and found no important and consistent morphological differences between A. celata from Europe, A. celata from Nova Scotia, and A. wrangeli (Casey) from Alaska. American specimens of A. celata have slightly more pronounced granulation of the forebody, a difference we attribute to infraspecific variation. Therefore, we regard all these specimens as belonging to the same species of A. celata and consequently regard A. wrangeli (Casey) syn. nov. as a synonym of A. celata ( Erichson 1837) .

Atheta irrita Casey ( Figures 6­11 ) was described from specimens collected in Nevada (Esmeralda County) and to date it is known only from this jurisdiction ( Casey 1911). Con­ sequently its discovery in Nova Scotia is a very substantial range extension (~ 4,800 km) for this species, and its discovery in an owl's nest represents the first bionomic information about it. As in the case of A. celata , it is noteworthy that the species was found in nests of two different host species at sites that are circa 130 kilometers apart, on both the mainland and Cape Breton Island, also suggesting that this species may be widely distributed in Nova Scotia in suitable habitats.

Examination of materials in the Laurentian Forestry Center has revealed 12 additional specimens of this species, all collected in Québec at St.­Jacques­de­Leeds, Erabliére in Lindgren funnel traps [9 June 1993, 1 female; 25 June 1993, 2 males; 9 June 1993, 2 females; 7 July 1993, 1 female; 16 July 1993, 1 male; 19 July 1993, 1 female; 26 July 1993, 3 females; 28 July 1993, 1 male] indicating that this species readily disperses aerially.

Atheta pseudocrenuliventris Klimaszewski was recently described by Klimaszewski et al. (2005) and was known only from 11 specimens collected in the Acadia Research Forest in New Brunswick, Canada. Specimens there were collected in pitfall traps mainly in mixed spruce ( Picea spp.)­deciduous forests. Its discovery in a boreal owl nest is the first bionomic information about the species, perhaps indicating that it is a regular inhabitant of these specialized micro­environments.

Bisnius cephalotes (Gravenhorst) is an adventive Palearctic species found throughout Europe, north to Iceland, east across Russia to Mongolia, south to Kazakhstan and west through Syria and Turkey to Egypt and Algeria in North Africa ( Herman 2001). The first reports from North America were from 1884 from Massachusetts and the "middle states", and from Washington State in 1882 ( Smetana 1995). It was first collected in Canada in 1917 in Manitoba and is now found scattered across much of the continent ( Smetana 1995). In Europe it has often been reported from bird and rodent nests ( Horion 1965) and in North America it has been reported from buzzard, squirrel, and fox nests ( Smetana 1995) and pigeon, stork, and buteo nests ( Hicks 1962, 1971). Krištofík et al. (2003) found it in Tengmalm's owl ( Aegolius f. funereus ) nests in Europe, however in the present study it was collected from a northern saw­whet owl nest.

Philonthus carbonarius (Gravenhorst) is an adventive Palearctic species found throughout Europe, south to North Africa, east through Turkey, the Caucasus and Iran to India and Nepal, and north through Central Asia to Russia ( Herman 2001). The earliest records from North America are specimens collected in Newfoundland in 1905. The species was then found in Nova Scotia; in Queens County (1909), Port Medway (1910), and Truro (1912) ( Smetana 1995). It is now widely distributed in eastern North America from Newfoundland south to West Virginia, and west to Illinois and Minnesota; on the west coast from British Columbia, Washington, Oregon, and Idaho; and at scattered localities in the central part of the continent, north to the Yukon, and south to Louisiana ( Smetana 1995).

Philonthus carbonarius is found in a wide variety of mostly open habitats in various ground debris, leaf litter, and under stones; also in various decaying matter, horse and cow dung, compost, and in flood debris ( Smetana 1995). Osella & Zanetti (1975) recorded it from mammal nests in Italy. In this study P. carbonarius was recorded in a boreal owl nest.

Philonthus politus (Linné) is an adventive Palearctic species found throughout Europe, south to North Africa, east through Turkey, the Caucasus, Iran and Central Asia to Mongolia and China; north to Russia, and south to India ( Herman 2001). It was first reported in North America by Kirby (1837) from specimens collected by Captain Basil Hall in Nova Scotia. It is now widely distributed throughout much of North America ( Smetana 1995). It is found in all kinds of decaying organic matter and has frequently been reported in the nests of various species of birds ( Hicks 1959, 1971) and mammals ( Smetana 1995). In this study P. politus was recorded in a boreal owl nest.

Figures

FIGURE 1. Habitus photograph of Atheta (Datomicra) celata (Erichson).

FIGURES 2­5. Genitalia and terminalia of Atheta (Datomicra) celata (Erichson): 2, median lobe of aedeagus in dorsal view; 3, median lobe of aedeagus in lateral view; 4, male tergite VIII; 5, spermatheca in lateral view.

FIGURE 6. Habitus photograph of Atheta irrita Casey.

FIGURES. 7–11. Genitalia and terminalia of Atheta irrita Casey: 7, median lobe of aedeagus in dorsal view; 8, median lobe of aedeagus in lateral view; 9, male tergite VIII; 10, 11, spermatheca in lateral view.