Survival of First-Instar Larvae of Hypoderma Lineatum (Diptera: Oestridae) Implanted in Heterologous Murine Hosts1

First-instar larvae of the common cattle grub, Hypoderma lineatum , implanted in the backs of laboratory white mice usually migrated to the thoracic and abdominal cavities where they were encapsulated by fibrous tissues of the host. These larvae did not grow but some survived at least 10 months. Mice died as a consequence of myiasis only during the first 3 weeks after the implantation. Apparently, migrating larvae frequently caused lethal lesions in the host's vital organs.