HOST, NEST, AND ECOLOGICAL RELATIONSHIPS OF SPECIES OF PROTOCALLIPHORA (DIPTERA, CALLIPHORIDAE)

A total of 4781 nests of 110 species of birds was examined for the presence of Protocalliphora in several localities in Ontario, Canada, and the intermountain region of northern Utah. Twenty species belonging to this genus were found in 1621 (33.8%) nests of 73 avian species. Some species, such as P. chrysorrhoea and P. halli, showed strong host preferences, whereas others, such as P. metallica and P. interrupta, preferred specific nest environments. The nests of birds that live in colonies and (or) return to the same site annually were more frequently and heavily infested than those of other birds. In Utah, where 17 species of Protocalliphora occurred, most species showed a degree of host preference, whereas in Ontario, where there were only 9 species, most species preferred specific nest sites. Of the 20 species of Protocalliphora collected during this study, 3 were found exclusively in Ontario and 11 in Utah, with 6 species common to both study areas.