Notes on sugar feeding and selected wild mammalian hosts of black flies (Diptera: Simuliidae) in Newfoundland.

Abstract

This study, done on the Avalon Peninsula, Newfoundland, identified selected wild mammalian hosts and quantified the incidence of sugar feeding for several species (species complexes) of black flies. Female flies were taken from fox, snowshoe hare, lynx, caribou, and human baits. Simulium truncatum/venustum complex females took blood from fox, lynx, rabbit, and caribou and were frequently taken in sweep net collections around humans. Blood-fed females of the Simulium rostratum/verecundum complex were collected only from caribou, were rarely attracted to the other mammalian baits, and were not attracted to humans. Although most females had sugar-free before seeking a host, significant interspecific differences in the incidence of fructose-positive females were found among the four species (species complexes) examined (Prosimulium mixtum, 92.9%; S. truncatum/venustum complex, 87.4%; Stegopterna mutata (triploid cytospecies), 83.3%; Simulium vittatum complex, 67.4%). No significant differences were found in the proportion of sugar-fed flies among three habitats examined (forest, scrubland, and pasture) for either P. mixtum or the S. truncatum/venustum complex. However, the percentage of sugar-fed S. truncatum/venustum complex females was significantly higher in the evening than in the morning. Time of day did not influence the incidence of sugar-fed P. mixtum.