Lucilia illustris

Distinguished from similar Lucilia species by the black bucca (cheeks) with gray pollinose, orange-tipped second antennal segment, and absence of a costal spine on the wing. The thorax shows silvery pollen and a dark dorsal line. The metallic blue-green coloration with bronze and purple reflections differs from the more uniformly green L. sericata and the copper-bronze L. cuprina. First instar larvae have difficulty determining spine dispersion due to unpigmented segments; second instar shows complete anterior spine bands on segments 2–9 with ventral-lateral spines only on segment 8; third instar has complete spine bands on segments 2–10 with five to six irregular rows on segment 11 and a smooth dorsal surface on segment 12. Posterior spiracles are large and darkly pigmented with six to eight relatively large branches on anterior spiracles.

Adults are 6–9 mm in length. The thorax is metallic blue-green with bronze and purple reflections; silvery pollen may appear on the dorsal surface with a dark longitudinal line. The bucca (cheeks) are black with gray pollinose and black hairs. Antennae: first segment black, second orange-tipped, third segment dark brown or black and approximately three times the length of the second. The arista is dark with long dark cilia. The back of the head is black with three to four rows of black cilia behind the eyes. Legs are black; wings are translucent without a costal spine. The abdomen matches the thorax in coloration but may appear slightly white in certain lights; the first segment has metallic and dark brown coloring, the second segment shows a slight central spot indication on the anterior margin, and the third and fourth segments bear long upright bristles with the fourth also having scattered hairs and a marginal row of bristles.

Associated with carrion in sunlit or bright areas. Adults visit flowering plants. Larval development occurs on decomposing animal matter, with a documented preference for cooler conditions compared to other blow fly species.

Recorded from Belgium, Denmark, Norway, and Sweden. The species has been documented in experimental studies involving hosts from South and Southeast Asia (India region), suggesting broader distribution in the Palaearctic region.

Active during cooler periods; at ambient temperatures around 7.7°C, L. illustris typically constitutes the largest maggot population on carcasses. Adult lifespan approximately three weeks.

Adults feed on flowers. Females require carrion protein for egg maturation. Larvae are carrion feeders; in experimental conditions, larvae fed first on brain tissue of living vertebrates before other soft tissues.

• Carrion - breeding substratePrimary oviposition site; females lay approximately 200 eggs per batch, up to 10 batches per lifetime
• Open wounds - occasional oviposition siteSecondary site for egg deposition
• Excrement - occasional oviposition siteRarely used for egg laying
• Clarias batrachus - experimental hostLarvae entered body and killed host; fed on brain first
• Bufo melanostictus - experimental hostLarvae entered body and killed host
• Rana tigrina - experimental hostLarvae entered body and killed host
• Hemidactylus fluviviridis - experimental hostLarvae entered body and killed host
• Columba livia - experimental hostLarvae entered body and killed host; warm-blooded host showed shortest larval development period
• Suncus murinus - experimental hostLarvae entered body and killed host; warm-blooded host showed shortest larval development period
• Sheep - facultative myiasis agentImplicated in myiasis in northerly Palaearctic regions; primarily feeds on necrotic tissue
• Pheasants - disease vectorLarvae mechanically vector Clostridium botulinum from infected carrion to live birds

Eggs hatch in approximately 24 hours at 25°C. Larvae pass through three instars, molting between each. First instar: segments 2–9 with full spine sets as anterior borders, segment 8 with lighter spines, segment 9 with nearly colorless reduced spines, segment 10 with several light rows, segment 11 with two to three dark rows posteriorly, segment 12 with tubercles. Second instar: segments 2–9 with complete anterior spine bands, segment 8 with ventral-lateral spines only, segments 9–12 with posterior spine bands, cephaloskeleton with dorsal cornua of consistent width. Third instar: complete spine bands on segments 2–10, segment 11 with five to six irregular rows, segment 12 smooth dorsally, large dark posterior spiracles. Larvae pupate underground after third instar. Adult emergence averages 10 days under ideal conditions. Development from egg to third instar can occur in as few as 14 days from time of death. Larval development is shorter on living tissue than on dead animals, shortest on living warm-blooded hosts.

Adults are rapidly attracted to carrion. Mating occurs near oviposition sites. Females aggregate in masses around egg-laying locations. Temperature strongly influences development rate. Larvae show tissue feeding preference for brain tissue in experimental parasitism conditions. Third instar larvae disperse from carrion to pupate underground. The species exhibits facultative myiasis behavior, primarily targeting necrotic tissue on living hosts.

Decomposer of animal remains. Facultative parasite capable of causing myiasis in necrotic tissue. Mechanical vector of Clostridium botulinum in avian populations. Competitor with other blow fly species on carrion, with temporal separation based on temperature preferences.

Primary forensic indicator species for estimating time and place of death due to predictable development and preference for sunlit carrion. Used in maggot debridement therapy because it causes myiasis only in necrotic tissue, making it safer than species that attack healthy tissue. Potential economic impact through sheep myiasis in northern Palaearctic regions and through vectoring avian botulism in pheasant production. First described by Johann Wilhelm Meigen in 1826; specific epithet means 'brilliant' in Latin.

• Lucilia sericataCommon green bottle fly; more uniformly green without bronze-purple reflections; has costal spine; second antennal segment not orange-tipped; bucca not black with gray pollinose
• Lucilia cuprinaAustralian sheep blow fly; copper-bronze coloration; introduced worldwide; causes primary myiasis in living sheep rather than facultative myiasis in necrotic tissue
• Phormia reginaBlack blow fly; black or deep metallic blue-black coloration; spring and fall activity period; delays oviposition compared to immediate egg-laying by Lucilia species
• Chrysomya rufifaciesHairy maggot blow fly; predatory on other maggot species; summer activity; introduced Australian native in southern United States

• blow fly
• green bottle fly
• forensic entomology
• carrion
• maggot debridement therapy
• myiasis
• decomposer

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Bohart Museum Features UC Davis Forensic Entomologist Bob Kimsey | Bug Squad
• Learning About the Importance of Blow Flies Through Maggot Art | Bug Squad
• How Blow Flies Compete (or Not) for Decomposition Duties
• Entomological Medicine: Working to Bring Maggot Therapy Into Wider Use
• Bug Eric: Zebra Jumper
• Bug Eric: What's on Dat Scat?
• Studies on the behaviour of Lucilia illustris Meigen as a parasite of vertebrates under experimental conditions