314 Cruz et al. Revista Brasileira de Entomologia 53(2): 314–317, junho 2009

Bot flies of the genus Cuterebra are restricted to the New World and are distributed throughout most of the temperate and tropical areas. Their larvae are obligatory parasites of mammals, producing myiasis in dermic and subdermic tissues of these animals (Catts 1982; Pape 2001). There is almost 70 species of Cuterebra and these flies are one of the most highly studied groups of insect parasites of New World wild mammals (Slansky 2007). However, the knowledge available on the ecology and natural history of most species comes from studies carried out in temperate regions (e.g. Wolf & Batzli 2001; Alcock & Kemp 2004; Jaffe et al. 2005). In the Neotropical region, the studies concerning the prevalence and dynamics of bot fly larval parasitism in wild mammals are scarce and have been carried out mainly with rodents. These studies have showed higher prevalence of bot fly larval parasitism in warm-wet season of the year, although few longitudinal studies Prevalence of larvae of the bot fly Cuterebra simulans (Diptera, Oestridae) on Gracilinanus microtarsus (Didelphimorphia, Didelphidae) in southeastern Cerrado from Brazi