Biological control is the use of living organisms to reduce pest or disease populations. In cannabis it includes predators (predatory mites, Orius, lacewings, ladybirds), parasitoids (wasps such as Aphidius), entomopathogenic nematodes (Steinernema feltiae), insect-killing microbes (Bacillus thuringiensis, Beauveria bassiana) and antagonistic microbes in the root zone. It is a core pillar of IPM, especially because so few chemical options are permitted on cannabis.
In practice
Biocontrol works best preventively: release in veg while pests are scarce, match each organism to the pest and the room's temperature and humidity, and keep incompatible sprays away. It is slow compared with a knock-down spray and needs scouting to check establishment. Indoor rooms suit it because the agents cannot fly away easily. Microbial products are pesticides in many jurisdictions and must be registered; check what is registered for cannabis locally. Order from suppliers who guarantee live counts and ship quickly; dead beneficials fix nothing.
Don't confuse with
- Cultural control: changing how the crop is grown.
- Biostimulants: products aimed at plant growth, not pest suppression.
- Organic pesticides: plant- or mineral-derived chemicals, not living organisms.
Mites, mostly of the family Phytoseiidae, released as biological control to eat pest mites, thrips larvae, whitefly eggs or fungus gnat larvae.An entomopathogenic nematode applied as a soil drench whose infective juveniles enter fungus gnat larvae and thrips pupae and kill them with symbiotic bacteria.A soil bacterium whose crystal proteins kill caterpillars after they eat treated leaves; subspecies kurstaki and aizawai are the strains used against budworms.An insect-killing fungus whose spores germinate on contact, penetrate the cuticle and kill soft-bodied pests such as whiteflies, thrips, aphids and root aphids.The root zone is the volume of medium or solution where a plant's roots live, including its water, air, temperature, pH, EC and microbes.Integrated pest management: preventing and controlling pests by combining monitoring, prevention, cultural, biological and, as a last resort, chemical tools against set action thresholds.Pest and disease prevention by changing how the crop is grown, such as humidity, airflow, spacing, watering and cultivar choice, so pests and pathogens struggle to establish.A biostimulant is a product claimed to improve plant growth, uptake or stress tolerance by means other than supplying nutrients, such as seaweed extract, humics, amino acids or microbes.Tiny parasitic wasps of the genus Aphidius that lay eggs inside aphids; the larva kills the host from inside, leaving a swollen tan mummy.Releasing beneficial organisms before a pest is found, so a standing population is ready to catch the first arrivals rather than chase an outbreak.
