FECUNDITY, OVARIAN DEVELOPMENT, AND PHYSIOLOGICAL AGE IN ADULT BLACK-FLIES (SIMULIIDAE) WITH SOME OBSERVATIONS ON VERTICAL DISTRIBUTION

Abstract

<p>Reproductive potential and its seasonal fulfillmentwas studied in several mammalophilic and ornithophilic black-flies near Hamilton and in Algonquin Park, Ontario.In all species examined there was variation in adult female size. A relationship was established between both potentialand actual fecundity, and fly size.</p> <p>In autogenous species there was variation in thestage of ovarian development at emergence, but the stage was consistently more advanced than that in newly emerged anautogenous species. In anautogenous species, some ovarian development occurred after emergence until a resting stage, considered to be stage Ila.</p> <p>Changes in the proportion of parous flies in onemammalophilic and three ornithophilic species was monitored for two seasons and other conditions such as mating, stage of ovarian development, and relict eggs were recorded.</p> <p>Studies of vertical distribution of Simulium venustum females in an open spruce canopy demonstrated fly movementsfrom the canopy to ground, level during the day until lateafternoon and subsequent movements back up to the canopy inthe evening.</p>