Blue Bottle Fly

Calliphora vomitoria — the blue bottle fly — is one of the most familiar large flies in temperate human environments and a centerpiece species of two scientific disciplines: forensic entomology and medical maggot therapy. Adults are 10-14 mm with brilliant metallic blue-black bodies and red eyes. Females are attracted to fresh decomposing animal matter (carrion, raw meat, animal feces) by olfactory cues including sulfur volatiles released by decay; she lays clusters of 100-300 eggs at the substrate edge. Eggs hatch in 12-24 hours; larvae develop through three instars over 5-10 days; pupae develop in soil for 7-14 days; adults emerge and the cycle repeats. The precision of larval development timing (which depends on temperature in well-characterized ways) makes the species the gold-standard organism in forensic entomology: investigators collect maggots from a body, identify the species and instar, account for ambient temperature history, and calculate the post-mortem interval (often to within hours for bodies in the first 1-2 weeks). The species is also the foundational organism in medical maggot debridement therapy. The closely related Lucilia sericata (the green bottle fly) is the clinically-approved species (FDA-cleared in 2004) — sterile lab-reared larvae are placed in non-healing chronic wounds (diabetic ulcers, pressure sores, post-surgical wounds), where they consume dead tissue, secrete antimicrobial compounds that kill MRSA and other bacteria, and stimulate granulation and healing. The technique was used informally for centuries (Civil War surgeons noticed wound healing improved when maggots colonized wounds) and was reintroduced into modern medicine in the 1990s. The species' Latin name 'vomitoria' references the documented habit of regurgitating digestive saliva to liquefy solid food before extracting it through the spongy labellum.