THE MIRID (HEMIPTERA) FAUNA OF SOLIDAGO CANADENSIS (ASTERACEA) IN SOUTH-EASTERN ONTARIO

Forty-six species of adult Miridae were recorded from Solidago canadensis L. in south-eastern Ontario. Major resident (breeding) species were determined on the basis of the relative abundance of nymphal and adult populations recorded from six plot-years. Although the composition of the mirid fauna varies temporally, over 90% of the Miridae belong to the following group of seven species: Slaterocoris breviatus (Kngt.), S. atritibialis (Kngt.), Lygus lineolaris (Beauv.), L. vanduzeei Kngt., Plagiognathus cuneatus Kngt., P. politus Uhl., and Polymerus venaticus (Uhl.).Total nymphal abundance is seasonally bimodal, relating to species differences in overwintering stage. The Lygus species overwinter as adults, and nymphs are abundant primarily in August, The remaining five species overwinter as eggs and their nymphs are present primarily during May to mid-July. In contrast to the bimodal phenology exhibited by nymphs, adults are temporally grouped in the mid- to late season, with adults of both overwintering classes overlapping. The adults, however, follow a characteristic sequence of initial occurrence, from early to late season, of: S. atritibialis, P. venaticus, L. vanduzeei, S. breviatus, P. politus, P. cuneatus, and L. lineolaris.