Black Flies Attacking Livestock: Simulium arcticum Malloch and Simulium luggeri Nicholson & Mickel (Diptera: Simuliidae)

The livestock-attacking black flies, Simulium arcticum Malloch and Simulium luggeri Nicholson & Mickel, are important pests of cattle and wild ungulates in the northern great plains of Canada. Other black fly species are pests of vertebrates including humans in other parts of the world. Females of S. arcticum and S. luggeri are greyish or brownish with the dorsum of the thorax uniformly colored. They differ in appearance (the coloration of the tibia of the hind leg is entirely dark in S. luggeri, but the basal half is white in S. arcticum), and features of the genitalia.

Damage

Economic losses occur due to the massive attacks by female black flies seeking a bloodmeal needed for production of eggs. Dispersal in search of hosts may be 150 km from the rivers where emergence and oviposition take place. In parts of Saskatchewan and Alberta, black flies are limiting to cattle production. Cattle harassed by attacking black flies become frightened and bunch together to escape the blood-seeking...