NOVA SCOTIA: Cumberland County: Parrsboro, 12 August 1947, R. McDunnough, 9 specimens, CNC; Halifax County: Halifax, 26 August 1945, D.C. Ferguson, NSMC; Port Wallis, 24 May 1953, D. Gray, NSMC; Kings County: Evangeline Beach, 22 November 1953, D.C. Ferguson, NSMC.
This adventive Palearctic species was first reported in Nova Scotia by Chapin (1956). The above records establish its presence in the province as early as 1945. It was accidentally introduced to North America and first recorded in 1912 in Massachusetts (Schaeffer 1912). Since then it has spread along the American seaboard and the St Lawrence River waterway from Ohio to the Maritimes Provinces and Newfoundland. Watson (1979) and Wheeler & Hoebeke (1981) both document its changing distribution and discuss the role of the St. Lawrence Seaway and the railway system in facilitating its dispersion.