Obligate Myiasis
Definition
Myiasis caused by species whose larvae must develop in living tissue to complete their life cycle. The New World screwworm (Cochliomyia hominivorax) and Old World screwworm (Chrysomya bezziana) are the key examples; their presence alone indicates active parasitism.
- Definition
- Myiasis requiring living tissue for larval development
- Key species
- Cochliomyia hominivorax (New World screwworm)
- Key species (Old World)
- Chrysomya bezziana
- Forensic significance
- Presence alone indicates active parasitism
Common questions
How does obligate myiasis differ from facultative myiasis in forensic significance?+
Facultative species normally breed in carrion or decaying matter and only infest living tissue opportunistically, usually where a wound or neglect condition already exists. Obligate species cannot complete development anywhere except living tissue, so finding them is direct evidence the host was alive when infestation began, which matters in neglect and elder-abuse investigations.
Why are screwworm species particularly significant compared to other myiasis-causing flies?+
Screwworm larvae actively feed on healthy living tissue rather than only necrotic material, causing progressive and often severe wound enlargement. Their geographic distribution is also more restricted than common facultative species, so identifying them narrows the possible location and timeframe of the infestation.
Can obligate myiasis larvae be used to estimate a minimum period of neglect?+
Yes, because the larvae require living tissue and develop through known instar stages at temperature-dependent rates, their developmental stage can be used, similarly to postmortem interval estimation, to establish a minimum duration the wound was left untreated.
Related terms
- Background Infestation
- Pre-existing insect activity in a property unrelated to the victim. The entomologist must distinguish insect evidence directly linked to the victim (on...
- Duty of Care Failure
- In neglect prosecutions, the legal standard requires showing that a carer had a duty to the victim, failed to meet it, and...
- Facultative Myiasis
- Myiasis caused by species that normally breed in carrion or organic debris but can infest living tissue, particularly necrotic wounds. Lucilia sericata,...
- Infestation Age
- The minimum period an infestation has been established, back-calculated from the oldest (most developed) larval stage present using accumulated temperature data. Gives...
- Myiasis
- Infestation of a living human or other vertebrate by the larvae of flies, which feed on living or necrotic tissue, body fluids,...