Cattle grubs (Hypoderma lineatum and Hypoderma bovis) are obligate parasites that cause myiasis in cattle in the Northern Hemisphere. Larval stages, migrating within the host body and in subdermal warbles, cause marked economic losses and increased susceptibility to other diseases. Macrocyclic lactones are highly effective against all larval stages, and the use of these drugs in timed treatment regimens has almost eradicated cattle grub infestations in several countries.
Hypodermiasis of cattle in the Northern Hemisphere is due to infection with the larvae of botflies or warble flies (cattle grubs) of Hypoderma spp (order Diptera, family Oestridae). In Central and South America, larvae (tropical warbles) of Dermatobia hominis (order Diptera, family Cuterebridae) are important parasites affecting cattle.