Vol. 91, No. 5, November & December 1980 155 TWO AGGREGATIONS OF CALOSOMA FRIGIDUM (COLEOPTERA: CARABIDAE) IN ONTARIO DURING 1976 1 William J. Crins 2 ABSTRACT: Two aggregations of the carabid, Calosoma frigidum Kirby, are described from Ontario. Large populations in Algonquin Park during June 1976 occurred concurrently with large populations of a prey species, Operophtera bruceata (Hulst).-> Observations about movements of the beetles within areas of high density are presented, and a high degree of flight activity was particularly significant. The second aggregation involved a mass flight of C. frigidum, and evidence is provided which suggests that meteorological factors were partly responsible for the flight. The Frigid Calosoma (Calosoma frigidum Kirby) is a large ground beetle of wooded habitats (Gidaspow 1959). It is widespread throughout southern Canada and the United States, occurring from Newfoundland to British Columbia, and south to Georgia and Texas (Burgess and Collins 1917, Gidaspow 1959). In spite of the wide range occupied by this species, little has been written regarding its movements or other aspects of its natural history. This is surprising in light of the fact that this species, and members of the genus Calosoma in general, are voracious predators of the larvae and pupae of many forest Lepidoptera and, as such, are potentially important as biological control agents. Poulin and O'Neil (1969) have shown that C. frigidum may be an important predator of the introduced pestiferous slug, Arion ater (L.). The present note describes some of the features related to two separate aggregations of C. frigidum in Ontario. The first involves an apparent close relationship with a concurrent outbreak of a prey species; the second is related to mass migration (cf. Johnson 1969). 1 . The Algonquin Park Aggregation During the period of 4-1 2 June 1 976, large numbers of C. frigidum were observed in woodlands in Peck and Canisbay Townships, Algonquin Provincial Park, Nipissing District, Ontario. The forests in which they were found were generally dry mesic, sugar maple (Acer saccharum Marsh. )-dominated woodlands over thin, loamy soils. These forests were being 1 Received June 6, 1980 Department of Biology, Erindale College, University of Toronto, Mississauga, Ontario. Canada L5L 1C6. '(Lepidoptera: Geometridae) ENT. NEWS 91(5): 155-158
BioStor
