Observations on the diversity, flight periods, emergence, swarming, and microdistribution of crane‐flies at Salem creek, Ontario (Diptera: Tipulidae, ptychopteridae, and trichoceridae)

Abstract

Abstract The present study is based on 2542 specimens of crane‐fly adults collected at Salem Creek, Ontario, in 1977. The fauna consisted of two species of Ptychopteridae, one of Trichoceridae and 86 of Tipulidae. Eight species were aquatic, 22 semi‐aquatic and 59 terrestrial. The peak flight period of crane‐flies was highest in May, decreased gradually in May‐September and dropped suddenly in October‐December. Six groups of species were designated according to their seasonal flight periods. 94% of the species were univoltine. The most abundant species, Antocha saxicola (aquatic), comprising 48.5% of the crane-fly fauna, and Limnophila aprilina (semi-aquatic), 8.5%, were both bivoltine. Swarming was observed in only six species; each swarm was composed of two to three species of crane-flies. All aquatic forms lived in riffles, while semi-aquatic species colonised sand and mud flats. Comparisons were made between sampling techniques used. Malaise and emergence traps were more efficient when compared to swe...