Chrysomya

Distinguish from other Calliphoridae by the combination of metallic coloration, thick setae on the meron, and plumose arista. Separate from Lucilia by meron setae arrangement and thoracic spiracle coloration. C. rufifacies is distinguished from C. megacephala by pale anterior thoracic spiracle (versus dark) and three faint thoracic stripes; C. megacephala has a larger head and prominent red eyes. Larval identification relies on tubercle presence (C. rufifacies) versus spiracle hair thickness (C. megacephala).

Associated with carrion, decaying organic matter, and human dwellings. Larvae develop in decomposing animal remains, fish, feces, and discarded organic materials. Some species occupy forests (normal form of C. megacephala), while others are synanthropic and abundant in urban environments.

Native to the Old World (Asia, Africa, Australia, Pacific Islands). C. rufifacies now established in southern United States (California, Arizona, Texas, Louisiana, Florida), Central America, and recently detected in Ontario, Canada. C. megacephala widespread in Asia, South Africa, South America, and established in southern United States.

Activity patterns vary by species and climate. C. rufifacies is primarily active in summer months. C. megacephala prefers higher temperatures and peaks during afternoon heat periods. P. regina overlaps seasonally with Chrysomya species in spring and fall, though warming climates may extend seasonal overlap.

Adults feed on decaying matter, excreta, and flowers. Larvae feed on carrion and decomposing organic material. C. rufifacies larvae are facultative predators of other dipteran larvae and may become cannibalistic when resources are scarce. C. albiceps feeds on diseased host tissue.

• Carrion/decomposing vertebrate remains - breeding substrateprimary oviposition site for most species
• Live mammals - oviposition siteC. bezziana lays eggs exclusively on live mammals, causing myiasis
• Cattle - hostmain host for C. bezziana myiasis
• Humans - hostmyiasis caused by several species, particularly C. bezziana
• Other domestic animals - hostmyiasis in various species

Holometabolous with four stages: egg, larva, pupa, adult. Eggs are approximately 1 mm, yellowish-white, laid in masses of 50–200 eggs (thousands in group oviposition). Eggs hatch in 8+ hours depending on temperature. Larvae progress through three instars, with post-feeding third instars dispersing to pupate in soil. Pupation lasts 7–12 days. Complete cycle: 190–598 hours depending on temperature. Adult lifespan approximately 6 weeks. C. rufifacies females oviposit approximately 5 days after mating.

Adults are attracted to carrion immediately upon death, with some species colonizing within minutes to hours. Larvae exhibit post-feeding dispersal behavior, moving away from carcasses to find pupation sites; C. megacephala disperses farther and buries deeper than C. albiceps. C. albiceps and C. rufifacies larvae are aggressive predators, attacking other maggot species during dispersal. C. rufifacies third instars can expel other maggots from feeding sites using fleshy tubercles. C. albiceps maintains aggregated dispersal patterns regardless of photophase or species presence; C. megacephala shifts from aggregated to random distribution when C. albiceps is present.

Primary colonizers of carrion, facilitating decomposition. Predatory species (C. rufifacies, C. albiceps) regulate populations of other blow fly species through intraguild predation, potentially altering carrion insect community composition and succession patterns. Mechanical vectors of pathogens due to association with filth and human dwellings.

Critical to forensic entomology for postmortem interval estimation due to predictable developmental rates and early colonization of corpses. C. bezziana is a major cause of myiasis in livestock and humans in the Old World. C. megacephala serves as fish bait in India. Potential disease vectors through mechanical transmission. C. rufifacies was historically used to treat osteomyeliasis through maggot therapy.

• LuciliaSimilar metallic coloration and carrion association; distinguished by meron setae and spiracle characteristics
• PhormiaOverlapping forensic significance and carrion ecology; Phormia regina has delayed oviposition compared to Chrysomya species
• CochliomyiaSimilar blow fly morphology and ecology; Chrysomya rufifacies predation significantly reduces Cochliomyia macellaria survivorship

The common name 'hairy maggot blow fly' for C. rufifacies refers to fleshy tubercles, not true hairs. Not all Chrysomya species conform to the 10–12 mm body size guideline. The genus is not exclusively Old World in distribution due to recent introductions to the Americas.

• forensic entomology
• blow fly
• carrion
• myiasis
• decomposition
• Old World
• invasive species
• predatory larvae
• metallic coloration
• medico-criminal

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Chrysomya rufifacies Archives - Entomology Today
• How Blow Flies Compete (or Not) for Decomposition Duties
• Uncategorized | Blog - Part 21
• Dead body feeding larvae useful in forensic investigations | Blog
• Three Blow Fly Species - Entomology Today
• Dispersal and Predation Behavior in Larvae of Chrysomya albiceps and Chrysomya megacephala (Diptera: Calliphoridae)
• Chrysomya rufifacies: Developmental Analysis Over Range of Temperature
• Dispersal and Burial Behavior in Larvae of Chrysomya megacephala and Chrysomya albiceps (Diptera, Calliphoridae)
• Effect of carcass model on maggot distribution and thermal generation of two forensically important blowfly species, Chrysomya megacephala (Fabricius) and Chrysomya rufifacies (Macquart)
• The Blowfly Chrysomya megacephala as a Vector of Pathogens Associated with Infectious Diseases.