Blood-feeding blackfly adults are among the most serious pests in the world, spreading serious human diseases (Merritt and Cummins 1996) and killing livestock by toxemia. They also feed on a great variety of wild hosts. Larvae require flowing water where they filter food from the passing current with unique fans while they are attached by silk and hooklets at the tip of the abdomen to clean stones or plants.
Fredeen (1981,1985) spent many years studying the biology and control of prairie blackflies, and Jarvis (1987) recently studied the biology of blackflies in the river. The following is from Fredeen and Jarvis. One hundred fifty species are known from North America. Six genera and 31 species are recorded from Saskatchewan, many being restricted to the northern Boreal., and the prairie flowing water fauna include 15 species from the Saskatchewan River system. These are Ectemnia taeniatifrons (Enderlein) (feeds on mammals) , Metacnephia saskatchewana Shewell and Fredeen, and many mammalophic species of Simulium, some of which are serious livestock pests ., these being Simulium arcticum Mallokc (seius pest of livestock) , S. bivitattum Malloch, S. decorum Walker, S. duplex Shewell and Fredeen, S. euryandminiculum Davies (feeds on birds), S. griseum Coquillet, S.luggeri Nicholson (serious pest of livestock), S. meridionale Riley, S rugglesi Nicholson and Mickel, S. tuberosum (Lundstroem), S. venustum Say, S. vittatum Zetterstedt, and S. verecundum Stone.
Below, University News, University of Saskatchewan, Saskatoon. August 1987. ** Blackfly control best in a quarter of a centrury, Lehmkuhl and his students credited by Saskatchewan Agriculture, new method of monitoring and control developed, blackflies virtually non-existant this year**