Incidental myiasis = occasional parasitism of atypical hosts by obligate
myiasis – producing flies
Cattle grub on horses, sheep nose bot in human
iii. Site Categorization
Gastrointestinal – can be accidental (larvae in fruit) or obligatory (horse bots)
Urogenital – invasion of urethra or genitalia by fly larvae, exposed openings
or infection attracting flies
Ocular-invasion of eye tissues, often by sheep nose bot, occasionally by
Nasopharyngeal – nasal and deep oral cavities, often associated with
infections, but some specialize
Auricular – invasion of ears, usually by blow flies and flesh flies
Cutaneous – blow flies, flesh flies, screwworms, some bot flies, traumatic
myiasis, when the skin is broken.
Overwintering – cuterebrids, - long pupal period, other bots, long larval stage
Adult longevity – few days for stomach bots, adults don’t feed, 1-2 weeks for
other bots, 1 month for muscids, calliphorids, sarcophagids
iii. Egg development
- nose bots and flesh flies – retain fertilized eggs, larviposit.
Others fertilize eggs as they oviposit, requires development.
at nest burrows,
on other flies, others on host.