Effects of temperature, quality of manure, and intraspecific competition on the development and survival of immature stages of the horn fly, Haematobia irritans irritans

Abstract

A series of experiments was conducted to determine the effect of temperature on development and mortality of the horn fly , Haematobia irritans irritans (L .). Rates of development were determined for 11 constant temperatures from 13°C to 37°C; resultant data were fitted to a thermodynamic model. Alternate low and 24°C temperature regimes were used to estimate rates of development at 4 °, 6 °, 8° and 10°C (temperatures below the survival threshold). Resulting estimates were found to agree closely with those predicted by the thermodynamic model. Horn fly immatures were unable to survive at constant temperatures above 37°C, indicating much less tolerance of high temperatures than face fly, Musca autumnalis DeGeer. Various low and high alternate temperatures were used to determine lethal temperatures under field conditions. Larvae could not survive daily 6-h exposures at 42°C nor could pupae survive daily 6-h exposures at 44°C. It was also shown that temperatures in dung pats could exceed these lethal temperatures during the summer months. Some immatures survived daily 8-h exposures at -2°C. ...