Blowfly
Definition
Common name for Calliphoridae. The female lays eggs in moist orifices (mouth, nose, eyes, wounds); eggs hatch in 8 to 24 hours in warm weather.
- Family
- Calliphoridae
- Oviposition sites
- Moist orifices: mouth, nose, eyes, wounds
- Egg hatch time
- 8 to 24 hours in warm weather
- Forensic role
- Primary coloniser used in minimum PMI estimation
Common questions
Why are blowflies the first insects to arrive at a body and useful for PMI estimation?+
Blowflies are highly sensitive to the volatile odours released almost immediately after death and can arrive within minutes in favourable conditions. Because their life-cycle stages progress at temperature-dependent, well-studied rates, the developmental stage of the oldest larvae present gives a minimum time since colonisation, which anchors a minimum postmortem interval estimate.
What factors can make blowfly-based PMI estimates unreliable?+
Ambient temperature strongly affects development rate, so an inaccurate local temperature record skews the estimate. Access to the body also matters: if orifices are obstructed, if the body is indoors, wrapped, or submerged, or if insecticide is present, colonisation can be delayed or prevented in ways that make the observed larval stage underestimate true elapsed time.
Related terms
- Accumulated Degree Days (ADD)
- The sum of daily mean temperatures above a threshold (usually 0 °C) over a period of interest. Used as a measure of...
- Calliphoridae
- The blowfly family: metallic-coloured flies that are typically the earliest colonisers of exposed remains. Forensically important genera include Calliphora, Lucilia, Chrysomya, and...
- Carrion Succession
- The predictable, roughly sequential replacement of insect communities on a decomposing body, driven by changing chemical substrate. Not a strict relay with...
- Flesh Fly
- Common name for Sarcophagidae. Unlike blowflies, the female deposits first-instar larvae directly, so casework often shows live maggots without an egg stage...
- Forensic Entomology
- The application of insect biology to legal investigations, most commonly using the developmental stage and species of insects colonising human remains to...
- Larval Instar
- One of three larval stages (L1, L2, L3) separated by moults. Each instar has distinctive mouth-hook and posterior spiracle morphology that allows...
- Muscidae
- A large family including house flies (Musca domestica) and stable flies (Stomoxys calcitrans). Non-metallic, typically dull grey or brown. Secondary or later...
- Post-Mortem Interval (PMI)
- The time elapsed between death and discovery or examination of remains. PMI estimation draws on multiple disciplines: soft tissue decomposition stage, insect...
- Sarconecrophagous
- Insects that feed directly on the corpse tissue, such as blowflies and flesh flies. The primary first-wave colonisers of carrion.
- Sarcophagidae
- The flesh fly family. Grey or black with longitudinal thoracic stripes and a chequered abdomen. Larviparous (deposit live larvae), so colonisation appears...
- Sarcosaprophagous
- Insects that feed on the corpse and on the by-products of decomposition, including some Muscidae and dermestid beetles in later waves.