Lucilia spp. Robineau-Desvoidy, 1830

Green bottle fly

Metallic-green carrion flies, one species' sterile maggots are used in hospitals to clean wounds.

Order: Diptera
Family: Calliphoridae
Group: Flies
Ontario status: Established, common

Why it matters

Germ carrier from waste to food. Remarkably, sterile larvae of Lucilia sericata are medical tools, maggot debridement therapy cleans dead tissue from wounds in hospitals.

Origin

Native across the northern hemisphere; the common green bottle (Lucilia sericata) is nearly worldwide.

Behavior

Fast, metallic-green fliers, active by day. Indoors, sudden numbers point to a dead animal or neglected garbage, same as blue bottles.

Living conditions

Breeds in carrion, garbage, and pet waste. Outdoors it is also the sheep blowfly, its maggots can infest living sheep (flystrike), a major livestock problem.

Signs of presence

Metallic green flies indoors in numbers
Maggots in garbage or near a decay odour
Loud buzzing localized to one area

Weaknesses

Same carrion dependence as blue bottles, remove the breeding material
Maggots need moisture; drying ends the cycle
Exclusion and waste management break it completely

Myths and facts

Myth All maggots in wounds are dangerous.
Reality Wild maggots in a wound signal neglect, but hospitals deliberately use sterile Lucilia sericata larvae to clean wounds, the context and the sterility make the difference.

Research notes

Morphology

Adult 8-10 mm; metallic green to coppery-bronze. Basicosta (wing-base scale) yellow to pale, the key separation from Calliphora (dark basicosta). Arista plumose to tip. Three postsutural dorsocentral bristles (a key character in the genus).

Diagnostics

Confirm by: 8-10 mm metallic green, yellow basicosta, arista feathered full length. Smaller and greener than Calliphora.

Easily confused with

Blue bottle fly, Calliphora spp. Yellow basicosta at the wing base means Lucilia; dark basicosta means Calliphora. Colour alone can mislead in poor light.

Life cycle

Egg: Batches on carrion or soiled wool; hatch within a day in warmth
Nymph or larva: Maggots feed on carrion; L. sericata also causes myiasis (flystrike) in sheep; 3 instars
Adult: Several weeks; feeds on nectar, carrion fluids, waste
Egg to adult: Approximately 10-14 days at 25 °C; longer in cool weather
Generations per year: Multiple; roughly 5-8 in warm regions, fewer in Ontario

Development

Complete metamorphosis: egg → larva (maggot, 3 instars) → pupa → adult.

Reproduction

High fecundity on carrion; rapid colonization, often co-dominant with Calliphora on carcasses.

Distribution

Native range: Holarctic; L. sericata now cosmopolitan
Ontario: Common; L. sericata abundant in urban and agricultural settings
Global: Temperate and subtropical regions worldwide

Ecology

Carrion, garbage, pet waste; L. sericata is the primary sheep-strike blowfly in many regions. Forensically important alongside Calliphora. Overwinters as pupae or adults.

Resistance

Documented in L. sericata sheep-blowfly populations: organophosphate resistance historically significant in Australia; some pyrethroid tolerance reported.

IPM implications

Same carcass-centred logic as blue bottles: find and remove the breeding material, sanitize, exclude. In livestock contexts, the biology (strike-susceptible soiled wool in warm humid weather) drives preventive shearing and crutching schedules, management follows the life cycle, not the adult fly.

Chemical ecology

Carrion sulfur volatiles drive long-range attraction; oviposition also cued by moisture and bacterial volatiles on the substrate.

Genetics and DNA

Reference genome of Lucilia sericata published 2021 (Davis et al., Genomics 113:3978-3988; 565.3 Mb, 14,704 predicted protein-coding genes).

Taxonomy

Diptera: Calliphoridae. Genus Lucilia Robineau-Desvoidy, 1830. Ontario species include L. sericata, L. illustris, L. coeruleiviridis.

Open questions

Competitive partitioning between Lucilia and Calliphora on Ontario carcasses across seasons.

References

Byrd & Castner (2010), Forensic Entomology (CRC Press)
Wall & Shearer (2001), Veterinary Ectoparasites (Blackwell), blowfly strike
Fischer, Lucilia sericata development data, primary literature