myiasis is the infestation of flesh of living animals by arthropods. "lucilia illustris" has been implicated as a myiasis agent in sheep in northerly palaearctic regions. "l. illustris" is also capable of infesting other wildlife and domesticated livestock which, along with sheep infestations, poses a potential economic problem. "l. illustris" is a facultative myiasis agent, which means that it does not depend on infestation of living animals to survive. it primarily feeds on necrotic tissue when attacking living hosts, which is thought to be part of the reason myiasis evolved as an extension of the normal feeding behavior of "l. illustris".