Lucilia silvarum

(Meigen, 1826)

common toad fly, Marsh Greenbottle Fly

Lucilia silvarum is a in the Calliphoridae, first described by Johann Wilhelm Meigen in 1826. are 4.5–10 mm with metallic green coloration and , making them difficult to distinguish from related green bottle flies. The has a Holarctic distribution across North America and Europe. Recent research has clarified its ecological role: it is primarily saprophagous on carrion and was identified as a primary colonizer of domestic cats in experimental studies, contradicting earlier assumptions that it was strictly associated with amphibian myiasis.

Lucilia silvarum by (c) Don Loarie, some rights reserved (CC BY), uploaded by Don Loarie. Used under a CC-BY license.

Lucilia silvarum by no rights reserved, uploaded by Uffe Harboe Nygaard. Used under a CC0 license.

Marsh Greenbottle Fly (Lucilia silvarum) - Guelph, Ontario 2020-07-26 by Ryan Hodnett. Used under a CC BY-SA 4.0 license.

Pronunciation

How to pronounce Lucilia silvarum: //luːˈsɪliə ˈsɪlvərəm//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Difficult to distinguish from other green bottle flies (Lucilia spp.) based on alone; accurate identification requires examination of specific morphological characters or molecular analysis; distinguished from L. sericata and L. cuprina by subtle differences in thoracic chaetotaxy and genitalia; historically confused with L. bufonivora, which is now recognized as the primary agent of anuran myiasis in North America rather than L. silvarum

Images

Habitat

Open grassy fields; areas with decomposing animal matter; warm-weather environments with temperatures between 24–29°C (75–85°F); associated with carrion, , and filth concentrations; saline conditions in California (incidental finding)

Distribution

Holarctic: widespread throughout North America and Europe; documented from British Columbia, Canada to southern Florida, USA; recorded in China, Denmark, Finland, southern Norway, Russia, and Canada; present in Vermont, USA; Sweden; Norway

Seasonality

Warm-weather fly; active during periods with temperatures between 24–29°C; presumably active spring through fall in temperate regions, with exact timing varying by latitude

Diet

Carrion; nectar and sweet liquids (); decomposing animal tissue; has been observed on domestic cat carcasses, rat carcasses, duck carcasses, and mice carcasses

Life Cycle

hatch in approximately one day; three larval instars: first instar at approximately 2 days, second instar at approximately 2.5 days, third instar at 4–5 days; prepupal wandering stage occurs 8–12 days after oviposition, with larvae reaching up to 12 mm; occurs after approximately 18–24 days depending on atmospheric conditions; development rates vary with temperature, humidity, and other environmental factors

Behavior

locate carrion by olfaction, attracted to sulfur-based and ammonium-rich volatile compounds; uses visual stimuli to supplement olfactory cues when locating decomposing remains; arrives at remains almost immediately after exposure; females oviposit on carrion; larvae exhibit post-feeding (wandering) before

Ecological Role

Primary colonizer of decomposing remains; contributes to decomposition and nutrient cycling; forensically relevant for estimating time of and minimum postmortem interval; part of initial wave of insects arriving at fresh remains; may prefer smaller carcasses or resources with low competition

Human Relevance

: important for estimating time of death in human and animal cases; one of the first to colonize corpses in the United States and Canada; empty indicates minimum postmortem interval of at least 20 days; relevant for animal cruelty investigations; NOT used in (medical debridement uses L. sericata, not L. silvarum)

Similar Taxa

Lucilia sericataSimilar metallic green appearance and size; both common green bottle flies; L. sericata is the used in medicinal and is more extensively studied forensically
Lucilia cuprinaSimilar metallic green coloration; Australian sheep ; introduced worldwide by human commerce
Lucilia bufonivoraHistorically confused with L. silvarum; now recognized as the true agent of fatal anuran myiasis in North America, not L. silvarum; subtle morphological differences require expert examination to distinguish
Phormia reginaBlack blow fly with different coloration but similar forensic importance; differs in being black or deep metallic blue-black rather than green; seasonal activity pattern differs (spring and fall vs. warm weather)

Misconceptions

Previously believed to cause fatal myiasis in anurans (frogs and toads) in North America; recent molecular and morphological evidence (2019–2020) demonstrates that L. bufonivora, not L. silvarum, is responsible for anuran myiasis in North America; L. silvarum appears to be strictly saprophagous in both Nearctic and Palearctic regions