Distribution and Medical Ecology of the Blow Flies (Diptera: Calliphoridae) of Peru1

Abstract

The altitudinal distribution and medical ecology of 26 species of blow flies along an Andean transect in central Peru are given, based on ca. 25,000 flies collected in 1979, 1980, and 1981. Five species are reported for the first time from Peru: Hemilucilia hermanlenti Mello, Phaenicia eximia (Wiedemann), Phaenicia ochricornis (Wiedemann), Phaenicia sericata (Meigen), and Sarconesia versicolor Bigot. In the wet season, when flies are most abundant, and on the eastern slope of the Andes, species richness was greatest at 1,800 m at eusynanthropic and hemisynanthropic sites, and at 200 m at asynanthropic sites. Although the western slope had fewer species, richness was maximum near the same altitude. In general, species diversity was greater near human habitats than in the wild. Ten species showed an upward shift of 300 to 600 m in their range in the wet season, with few species invading another biotic zone. The synanthropic indices of 13 species at 200, 1,000, 2,500, and 4,000 m in wet and dry seasons are given. Three of five species showed increased synanthropy with elevation and two of eight species increased synanthropy in the dry season. The bait preferences of 20 species, the propensity of 14 species to enter homes, and the diurnal activity curves of 9 species are presented. Based on this study, the medically most important blow flies in Peru are Cochliomyia macellaria (F.), P. eximia, Phaenicia ibis (Shannon), Sarconesia magellanica (LeGuillou), Sarconesia chlorogaster (Wiedemann), and Compsomyiops spp., with a combined range from tropic to alpine zones. The ecological niches of 26 species are defined according to altitude, synanthropy, food preferences, endophily/exophily, and diurnal flight patterns.