Warble fly is a name given to the genus Hypoderma, large
flies which are
parasitic on
cattle and
deer. Other names include "heel flies", "bomb flies", and "gad flies", while their larvae are often called "cattle grubs". Common species of warble fly include Hypoderma lineatum and
Hypoderma bovis. The fly will lay eggs on the foreleg of the affected cattle. These will be ingested by licking, and be swallowed. Internal cycle involves the passing
oesophagus muscles and
spinal cord before subcutaneous re-emerging.When they re-emerge, the larvae cause many swellings ("warbles") under the skin, causing some harm to animals, but not as a general disease. It doesn't burrow into the flesh, but stays under the skin (hence, its scientific name Hypoderma). Nevertheless, when accidentally destroyed by pressure, the larvae can cause large
purulent swellings.
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