Blow flies

Definition

Adult flies of the family Calliphoridae (order Diptera), characterized by metallic blue, green, or bronze coloration, robust bodies, and rapid larval development on carrion, wounds, or decomposing organic matter. The larvae (maggots) are facultative or obligate agents of myiasis and are widely used as fishing bait (called 'gentles') and in maggot debridement therapy. Adults are among the earliest colonizers of vertebrate remains and serve as primary indicators in forensic entomology for estimating minimum postmortem intervals.

Etymology

From 'to blow' (to lay eggs in or on flesh, from the bloated appearance of fly-blown meat) + 'fly'; compare Old English 'flēogan' (to fly). The family name Calliphoridae derives from Greek 'kallos' (beauty) + 'phoros' (bearing), referring to the attractive metallic sheen of many species.

Example

Phormia regina and Chrysomya rufifacies are common North American blow flies whose predictable developmental rates on carrion allow forensic entomologists to estimate time since death within hours.

Synonyms

• calliphorids
• bluebottles
• greenbottles

Related Terms

• Calliphoridae
• myiasis
• Forensic entomology
• carrion ecology
• maggot debridement therapy
• Diptera
• sarcosaprophagy
• postmortem interval

Usage Notes

The common name 'blow fly' applies to the family Calliphoridae, though some species in related families (notably Sarcophagidae, the flesh flies) share similar habits and are sometimes confused with blow flies. The family is currently recognized as polyphyletic, with ongoing taxonomic revision potentially splitting it into multiple families. 'Bluebottle' and 'greenbottle' traditionally refer to metallic-colored blow flies, especially Calliphora and Lucilia species, but usage varies regionally. In forensic contexts, distinguishing blow flies from flesh flies is critical: blow flies typically arrive within minutes to hours of death, while flesh flies may arrive slightly later and have different developmental trajectories.