Western-montana
Guides
Cuterebra approximata
bot fly, rodent bot fly
Cuterebra approximata is a New World skin bot fly (family Oestridae) whose natural host is the deer mouse (Peromyscus maniculatus). First instar larvae enter the host through the external auditory meatus and migrate to the dorsal body region, where they form subcutaneous warbles. Larvae develop through three instars from July through September before exiting to pupate in soil. Adults are extremely short-lived, lacking functional mouthparts, and are active for approximately two weeks in late June to early July.