Peromyscus
Guides
Cuterebra fontinella
mouse bot fly
Cuterebra fontinella, commonly known as the mouse bot fly, is a New World oestrid fly that parasitizes small mammals, particularly the white-footed mouse (Peromyscus leucopus). Adults are short-lived, non-feeding, and resemble bumble bees in appearance. Females lay eggs on vegetation near host burrows; larvae enter through natural orifices or wounds, migrate internally, and develop subcutaneous warbles typically located in the inguinal region. The species exhibits bimodal seasonal activity with summer and autumn population peaks. Though primarily a rodent parasite, rare human cases of myiasis have been documented.
Cuterebra fontinella fontinella
mouse bot fly, white-footed mouse bot fly
Cuterebra fontinella fontinella is a subspecies of New World bot fly (family Oestridae) that parasitizes small mammals, primarily white-footed mice (Peromyscus leucopus). The adult flies are large, bumble bee-sized, and lack functional mouthparts, living only briefly to reproduce. Females lay eggs near host burrow entrances; larvae hatch in response to host body heat, enter through orifices or wounds, and develop subcutaneously for approximately one month before exiting to pupate in soil. Despite forming conspicuous warbles that can reach 5% of host body weight, infections appear to have minimal negative impact on host survival and may even correlate with increased longevity in some populations.