A Study of the Population of Insects Emerging as Adults from the Dundas Marsh, Hamilton, Ontario, During 1948

The first recorded studies of insects from the Dundas Marsh concern the phalaenid moths, Arz(rna obliquata and A. diffusa, whose larvae drill in the leaves of aquatic plants. Moffat (1888, 1888a) reported collecting A. obliquata from reeds and stumps in the vicinity of the marsh and Johnston (1889) recorded the occurrence of both of these species in his collections. Moffat (1889) also reported collecting A. obliquata and Nonagria fodians from a cat-tail, Typha, sp. In 1946 a few species of insects were collected about the marsh and in 1947 a project was undertaken to determine the times of first and last emergence and the periocd of maximum emergence of various species which emetge as adults from the water. These studies are discussed by Judd (1947, 1949, 1949a, 1950a). In 1948 a study was made of the population of insects emerging from the marsh from March to November, the present paper