Entomopathogens
Fungi, bacteria, nematodes and viruses that invade insects, kill them and use them as a substrate to grow. Their effects can be seen with the naked eye: cadavers covered with white mycelium or green spores, orange clubs, hanging caterpillars… Here are the ten main ones, each with a freely licensed photo.
🎬 Reports: entomopathogens on video ⚖️ Making, using, selling: what the law says by country
Status of on-farm production, use and sale of products based on insect fungi, bacteria or viruses (and Trichoderma). Checked every week.
| Country | Make on the farm | Use | Sell |
|---|---|---|---|
 European Union | ⛔ Forbidden without authorisation | 🏷️ Registered products only | 🏷️ Registered products only |
| Any micro-organism-based product used to protect crops must be approved (active substance) and authorised (product) under Regulation (EC) 1107/2009. A farmer may not multiply Beauveria, Metarhizium, Bt or Trichoderma for that purpose, even for their own farm. Checked on 01/11/2026 — Commission européenne – Micro-organismes en protection des plantes | |||
 United States | ⚠️ Under conditions | 🏷️ Registered products only | 🏷️ Registered products only |
| Microbial pesticides must be registered with the EPA (FIFRA) to be sold or distributed; micro-organisms are not on the exempt minimum-risk list. Production for own use, without distribution, depends on each state: some regulate it. Checked on 01/11/2026 — NPIC – Pesticides exemptés d'enregistrement (FIFRA) · Maine BPC – Production de pesticides pour usage personnel | |||
 Brazil | ⚠️ Under conditions | ✅ Allowed | 🏷️ Registered products only |
| Law 15.070 of December 2024 allows on-farm production of bio-inputs for own use without registration, under conditions (good practice, no sale of that production). Sale requires registration with the Ministry of Agriculture (MAPA). Its implementing rules are still under discussion. Checked on 01/11/2026 — Lei 15.070/2024 – Capítulo IV, produção para uso próprio · Câmara dos Deputados – Lei 15.070, de 23 de dezembro de 2024 | |||
 Colombia | 🔎 Not settled / to check | 🏷️ Registered products only | 🏷️ Registered products only |
| Agricultural bio-inputs must be registered with the ICA to be produced and marketed. The texts consulted set no specific rules for production intended only for the farm's own use: check with the ICA. Checked on 01/11/2026 — ICA – Circular externa n.º 4 del 21 de agosto de 2020 (bioinsumos) | |||
 Argentina | 🔎 Not settled / to check | 🔎 Not settled / to check | 🏷️ Registered products only |
| Commercial bio-inputs are registered with SENASA. SENASA is working on distinguishing small-scale bio-preparations from industrial bio-inputs; the rules for on-farm production are not yet settled. Checked on 01/11/2026 — Bichos de Campo – Le SENASA veut distinguer biopréparations et bio-intrants | |||
 Cuba | ✅ Allowed | ✅ Allowed | 🔎 Not settled / to check |
| A public network of Centres for the Reproduction of Entomophages and Entomopathogens (CREE) produces beneficial insects and micro-organisms locally for the country's farms. Checked on 01/11/2026 — SourceWatch – Centers for Production of Entomophages and Entomopathogens (Cuba) | |||
Other countries: being researched, added as they are documented.
Soil fungus found worldwide. Its spores germinate on the insect's cuticle and pass through it; after death the body becomes covered with a powdery white felt, like icing sugar, which releases new spores.
Soil fungus that also lives near roots. It mainly invades soil-dwelling larvae (white grubs) and locusts: the hardened cadaver is covered first with white mycelium, then with an olive-green powder of spores.
Fungus of temperate woods and meadows that develops inside buried moth caterpillars and pupae. In autumn, one or more bright orange clubs, 2 to 8 cm tall, grow from the mummified pupa and rise above the soil.
Tropical-forest fungus that invades carpenter ants. The invaded ant climbs into the vegetation, clamps its mandibles onto a leaf vein or stem and dies; a stalk then grows from the back of its head and scatters spores over the colony.
Soil bacterium that produces protein crystals as it forms its spores. Each subspecies acts on one group of insects (caterpillars, mosquito larvae, beetle larvae) that ingest them: they stop feeding within hours, and the dead caterpillar turns black and soft.
Fungus that invades flies. Late in the day the invaded fly climbs to a high point (plant, window), spreads its wings and dies; the swollen abdomen shows white bands from which the fungus shoots its spores around.
Common fungus in woodland litter and soil, on moth caterpillars and pupae. Small branched white stalks covered with a mealy powder of spores grow from the dead insect.
Fungal genus that now includes the former Lecanicillium (formerly Verticillium lecanii). They need high humidity; on aphids, whiteflies or scale insects they form a halo of white mycelium, and some species cover whole moths with small white spikes.
Microscopic soil worms that enter insect larvae and release an associated bacterium inside them. The larva dies within one or two days and changes colour: brick red with Heterorhabditis, ochre or brown with Steinernema; thousands of new nematodes then leave it for the soil.
Insect-specific viruses, mostly of caterpillars, each affecting only a few species. The invaded caterpillar climbs to the top of the plant, hangs head down and dies; its skin becomes fragile and releases a liquid full of virus particles.
Trichoderma, often mentioned alongside them, is not an entomopathogen: it is a soil fungus that colonises roots and other fungi (see its ingredient sheet). Ingredient sheet
Descriptive page. In the EU, some strains (Beauveria, Metarhizium, Bt, Lecanicillium, baculoviruses…) are plant-protection active substances: they may only be used as commercial products authorised in the country, never multiplied at home for that purpose. No homemade recipe is offered here.