The term “green fly” usually refers to the Common Green Bottle Fly, a highly common insect drawn to decomposing materials. These flies are not seeking fresh food but rather the specific byproducts of decay where their offspring can thrive. Understanding what attracts this scavenger is the first step in managing its presence around homes and businesses.
Identifying the Common Green Fly
The insect most people encounter and refer to as a “green fly” is typically the Common Green Bottle Fly (Lucilia sericata). This species is a type of blow fly, easily recognizable by its brilliant, metallic, blue-green or copper-green coloration and its size, which is slightly larger than a house fly. The common name “green fly” can sometimes confuse it with greenfly, which are actually small, soft-bodied plant pests called aphids. Aphids are sap-sucking insects. The Green Bottle Fly is a robust, fast-flying insect with large, reddish compound eyes. For homeowners, the metallic, buzzing blow fly is the true pest.
The Powerful Scents That Draw Them In
Green Bottle Flies are drawn to sources over long distances using highly developed chemoreceptors that detect volatile organic compounds (VOCs) released during decomposition. Their attraction is primarily driven by the need for a suitable place to lay their eggs, as the larvae, or maggots, feed exclusively on decaying matter. The main attractant categories all involve the breakdown of proteins and carbohydrates.
Decaying organic matter, such as dead animals or rotting meat, is the primary attractant. It provides an ideal, protein-rich nursery for the fly larvae. The specific odors that signal this material are sulfur compounds and indole, which are byproducts of putrefaction. Female flies are strongly compelled to locate the source of these compounds to ensure the survival of their young.
Another powerful lure is waste matter, including animal feces and garbage containing meat scraps. These materials emit odors like ammonia and various sulfides as bacteria break them down, signaling a viable food source for the next generation of flies. Adult flies will also feed on nectar and pollen from flowers, but they are driven to the unsanitary sources for breeding purposes.
Practical Steps for Source Removal
Effective management of Green Bottle Flies focuses on sanitation and eliminating their preferred breeding grounds. Since their presence indicates a nearby source of decomposition, the immediate action is to locate and remove the decaying material. This often involves checking behind appliances, in wall voids, or under structures for dead rodents or other small animals.
All outdoor and indoor garbage containers should be sealed with tight-fitting lids to contain odors and block access. Any meat or food waste should be bagged securely before placing it in the trash to prevent flies from laying eggs directly on the material. Regularly cleaning garbage cans with a solution containing an odor eliminator, such as borax, can remove residual scents that continue to attract the flies.
Pet waste must be removed from the yard immediately, as animal feces is a common breeding site for these flies. Home entry points also need attention. Repairing any tears in window screens or sealing cracks around doors will block the adult flies from entering the home. By removing the source of the attractive odors, the entire life cycle of the Green Bottle Fly is interrupted, preventing infestations.