Observations on the Spread of Cyzenis albicans (Fall.) (Tachinidae: Diptera), an Introduced Parasite of the Winter Moth, Operophtera brumata (L.), (Geometridae: Lepidoptera), in Nova Scotia

Extract

Cyzenis albicans (Fall.) has been introduced into Nova Scotia as a control measure against the winter moth, Operophtera brumata (L.). The parasite attacks the late larval stages of the winter moth, pupates within the host in the ground, and emerges in the spring. The first liberations were made at Oak Hill near Bridgewater and the dates of releases as well as the numbers released were reported by Graham (1958) as follows: 1954, 31; 1955, 1008; 1956, 1005; 1957, 250. Graham made recoveries of C. albicans from rearings of larvae collected at Oak Hill in 1956 and 1957 and found that parasitism was less than two per cent both years. While liberations have been made at other locations in the Province since 1957, no further releases have been made at or near Oak Hill.