File:CSIRO ScienceImage 115 The Tip of a Screw Worm Fly Larvae.jpg

English: This image shows the tip of a the screw worm fly larvae. This insect is a pest species. Wounding is usually a prerequisite for SWF strike. This may be wounding that occurs naturally such as the navels of newborn animals, or as a result of husbandry practices such as branding or castrating. It can even be from wounds as minor as tick bites. In sheep the fly can strike in the absence of a wound. In sheep the inner corner of the eye and the crutch are common sites for flystrike. The female fly lays her eggs on the edges of a wound and the larvae hatch within 12-20 hours. The larvae burrow deeply into tissue and feed causing extensive destruction. Wounds heal if treated rapidly but if left untreated may become reinfested causing persistent lesions, weight loss and occasionally death. Struck wounds have a strong, offensive odour and animals lick the wounds frequently. The greatest loss of animals is in newborns suffering from navel strike. Also available, electron microscope scan. See File:CSIRO ScienceImage 52 Screw Worm Fly Larvae Through Electron Microscope.jpg.