# Black soldier fly (Hermetia illucens) > A harmless, wasp-like fly whose larvae rapidly break down organic waste and are used as high-protein feed and composters. Source: https://insectscanner.com/species/black-soldier-fly/ (updated 2026-10-10) ## Is it dangerous? **Non-toxic.** Adults do not bite or sting and are not venomous. Larvae do not pose a bite risk. Gloves are sensible when handling larvae or compost to avoid contamination. Standard hygiene after handling is sufficient. **Pets:** Larvae are safe and widely used as pet food (reptiles, fish, poultry, chickens). Live larvae may stimulate foraging in pets. Ensure larvae are produced hygienically; avoid feeding wild-collected larvae to pets due to possible contaminants. ## Quick facts - Scientific name: Hermetia illucens - Also called: BSF, Black soldierfly, Soldier fly - Order: Diptera (Flies) - Family: Stratiomyidae (Soldier flies) - Size: 15-20 mm body length (wingspan ~20-25 mm) - Colours: Black, Metallic blue-black, Brown (larva), Cream (young larva) - Habitat: Near decaying organic matter: compost, manure, food-waste bins, agricultural waste sites, and warm, sheltered areas. - Range: Native to the Neotropics but now cosmopolitan in tropical and warm temperate regions worldwide; established in North America, South America, Africa, Asia, Europe (in warm locales) and Australia. - Active: Most active in warm months and warm climates; adults fly during daylight hours, especially in warm, sunny conditions. - Lifespan: Adults live about 7-14 days; larvae develop for 2-8 weeks depending on temperature and food quality. - Effect on plants: Composter - Pest: no ## Overview Hermetia illucens, the black soldier fly, is a medium-sized soldier fly native to the Americas and now established worldwide in warm regions. Adults look wasp-like but do not bite or sting and are not considered pests; their main ecological role is reproduction and egg-laying. The larvae are voracious decomposers of organic material and are widely used in composting, waste management and as livestock and pet feed because of their high protein and fat content. Adults live only a short time (typically about 1-2 weeks) and focus on mating and laying eggs near decaying plant and food waste. Larvae feed and grow for several weeks to months depending on temperature and food, then pupate and emerge as adults. They are important in recycling nutrients and reducing organic waste volume, and have become economically important in insect farming worldwide. ## How to identify it Adult black soldier flies are 15-20 mm long, slender and mostly black with a faint metallic sheen. They have a narrow 'waist' and a wasp-like silhouette; wings fold flat over the back when at rest. Two distinctive translucent 'windows' (pale patches) are visible near the base of the abdomen. Antennae are relatively long and flattened toward the tips. Larvae are maggot-like, thick, cylindrical, cream to tan when young and darken to brownish or reddish-brown as they age; mature larvae reach about 20-30 mm long and have a tough, leathery appearance. - Wasp-like black fly with narrow waist and folded wings; adults 15-20 mm long. - Two distinctive translucent pale 'windows' near the base of the abdomen. - Long antennae compared with common house flies. - Larvae are stout, tapered at one end, leathery, and 20-30 mm when mature. ## Lookalikes - **Other soldier flies** (Various Stratiomyidae): Other soldier flies are similar in shape but often differ in size, wing venation and the presence/absence of the translucent 'windows' at the base of the abdomen. Expert examination of wing veins and body details distinguishes them. - **House fly** (Musca domestica): House flies are smaller, more compact, with shorter antennae and different wing venation; they lack the wasp-like silhouette and translucent abdominal windows of BSF. - **Hoverflies (flower flies)** (Syrphidae spp.): Hoverflies often mimic wasps and hover near flowers and have different wing venation and eye placement; many hoverflies have bright yellow markings unlike the uniformly dark BSF. ## Life cycle - **Egg:** Females lay clusters of pale eggs in crevices near decomposing organic matter; eggs hatch in about 4 days in warm conditions. - **Larva (maggot):** Larvae feed on decaying organic material, growing through multiple instars over 2-8 weeks depending on temperature and food supply. - **Pupa:** Larvae pupate in a dry location; pupal stage lasts about 1-2 weeks before adults emerge. - **Adult (fly):** Adults emerge, mate and the females lay eggs; adults typically do not feed (they may sip water or nectar) and live about 1-2 weeks. ## Diet and predators - Young eat: Decaying organic matter: fruit and vegetable waste, manure, kitchen scraps, compost, brewery and food-industry waste. - Adults eat: Adults feed little; may take water or dilute nectar but do not feed on fresh food and do not bite. - Predators of the young: Birds, reptiles, amphibians, predatory insects, nematodes and microbial pathogens in waste substrates. - Predators of adults: Birds, spiders, predatory insects and some small mammals. ## Effect on plants and gardens Black soldier fly larvae break down decaying plant and animal matter; they do not feed on living plants and are not plant pests. ## Where and when to find it Look for adults around compost piles, manure, food-waste bins and warm sunny spots near decaying organic matter. Find larvae in the moist, decomposing layers of compost, manure heaps, or food-waste containers. - Best time: Warm months and during daylight hours; larvae are most active in warm, moist substrates and are easiest to find when digging into compost. - Tips: Keep a low angle and photograph adults perching on vegetation or near compost; for larvae, open a small section of compost and scan sifted material. Use gloves when handling larvae or substrate. ## Fun facts - Black soldier fly larvae can convert large amounts of organic waste into protein- and fat-rich biomass useful as animal feed. - Adults have mouthparts that are poorly developed for feeding; they live only long enough to reproduce. - BSF larvae produce antimicrobial compounds and can reduce populations of some harmful bacteria in waste substrates. - Industrial insect farms use BSF to recycle food-industry byproducts into feed, oils and compost. ## Frequently asked questions ### Are black soldier flies dangerous? No. Adults do not bite or sting and are not venomous. Larvae are not harmful when handled properly. ### Do black soldier flies spread disease? They are not major disease vectors like house flies. However, larvae and waste substrates can carry microbes, so handle with good hygiene. ### Why are black soldier flies in my compost or kitchen? Females lay eggs near decaying organic matter. If you have accessible food waste, compost piles or uncovered bins, BSF will be attracted to lay eggs. ### How do I get rid of black soldier flies? Reduce breeding sites: seal food-waste, keep compost covered and dry at the surface, remove wet decaying material, and use fine mesh on vents. For large problems, remove and properly compost or dispose of the infested material. ### Are black soldier fly larvae good for chickens and fish? Yes. BSF larvae are high-protein feed commonly used for chickens, fish and reptiles; source them from reputable suppliers or farms to ensure hygiene. --- More about this species: [iNaturalist](https://www.inaturalist.org/taxa/82177), [Wikipedia](https://en.wikipedia.org/wiki/Hermetia_illucens). Identify insects and spiders from a photo with the Insect Scanner iPhone app: https://apps.apple.com/app/id1543946563?pt=126685406&ct=web-markdown&mt=8 Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.