# Preventive release

> Releasing beneficial organisms before a pest is found, so a standing population is ready to catch the first arrivals rather than chase an outbreak.

- Canonical: https://genetixbay.com/knowledge/glossary/preventive-release.html
- Also written: preventative release, prophylactic release, inoculative release, preventive biocontrol, sachet release
- Glossary category: Pests and diseases · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

A preventive release is the introduction of [biological control](https://genetixbay.com/knowledge/glossary/biological-control.md) agents before a pest has been detected, or at very low levels. The goal is a resident population of predators or [parasitoids](https://genetixbay.com/knowledge/glossary/parasitoid.md) that can establish, breed on pollen or alternative prey, and suppress pests as they arrive. It contrasts with curative or inundative releases, which flood an existing outbreak.

## In practice

Common preventive programmes on cannabis: slow-release sachets of *[Neoseiulus cucumeris](https://genetixbay.com/knowledge/glossary/neoseiulus-cucumeris.md)* or *[Amblyseius swirskii](https://genetixbay.com/knowledge/glossary/amblyseius-swirskii.md)* hung in veg; *[Neoseiulus californicus](https://genetixbay.com/knowledge/glossary/neoseiulus-californicus.md)* across [mothers](https://genetixbay.com/knowledge/glossary/mother-plant.md); *[Stratiolaelaps scimitus](https://genetixbay.com/knowledge/glossary/stratiolaelaps-scimitus.md)* sprinkled on the medium of new clones; periodic *Aphidius* releases or [banker plants](https://genetixbay.com/knowledge/glossary/banker-plant.md). Preventive releases are usually timed from clone or early veg until a few weeks into flower, because getting predators established before flower is far easier than rescuing a flowering crop. They only work if the room's environment suits the species and no incompatible sprays follow.

## Don't confuse with

- **Curative release**: large numbers aimed at a known outbreak.
- **Banker plant**: a support system that breeds beneficials in place.
- **Spray schedule**: preventive chemistry by calendar.

## Related terms

[Biological control](https://genetixbay.com/knowledge/glossary/biological-control.md), [Neoseiulus californicus](https://genetixbay.com/knowledge/glossary/neoseiulus-californicus.md), [Amblyseius swirskii](https://genetixbay.com/knowledge/glossary/amblyseius-swirskii.md), [Neoseiulus cucumeris](https://genetixbay.com/knowledge/glossary/neoseiulus-cucumeris.md), [Action threshold](https://genetixbay.com/knowledge/glossary/action-threshold.md)

## Read more

- [Thrips on cannabis: life table, temperature, scouting and biological control](https://genetixbay.com/knowledge/pests/thrips.md)

## Sources

1. UConn IPM. Biological Control of Western Flower Thrips. https://ipm.cahnr.uconn.edu/ipm-biological-control-of-western-flower-thrips/
2. UConn IPM. Biological control of spider mites (2019 fact sheet). https://ipm.cahnr.uconn.edu/wp-content/uploads/sites/3216/2022/12/2019biologicalcontrolofspidermitesfinal2-1.pdf