Seasonal occurrence of, development of, and the influences of selected environmental factors on the larvae of Prosimulium and Simulium species of blackflies (Diptera: Simuliidae) found in the rivers of southwestern Alberta

Abstract

Larval development of Simulium arcticum Malloch (IIL-3), S. defoliarti Stone and Peterson (IIS-14.15), and S. tuberosum Lundström (FG) was documented for four rivers in southwestern Alberta from 1982 to 1984. Simulium arcticum (IIL-3) and S. tuberosum (FG) had seven instars; these two species were multivoltine with two or three generations per year, while S. defoliarti (IIS-14.15) was univoltine. Water temperature, river discharge, and turbidity were the only environmental factors of five parameters measured that were significantly correlated with the seasonal development of larvae of S. arcticum (IIL-3), S. defoliarti (IIS-14.15), S. vittatum Zetterstedt complex, S. tuberosum (FG), and Prosimulium onychodactylum Dyar and Shannon complex. Also, we speculate on the effect that food quality and quantity have on larval growth and development of blackfly species that breed in mountain rivers.