A preventive release is the introduction of biological control agents before a pest has been detected, or at very low levels. The goal is a resident population of predators or parasitoids 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 or Amblyseius swirskii hung in veg; Neoseiulus californicus across mothers; Stratiolaelaps scimitus sprinkled on the medium of new clones; periodic Aphidius releases or banker plants. 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.
Using living natural enemies, such as predators, parasitoids, nematodes and microbes, to suppress pests and diseases instead of, or before, chemical sprays.A predatory mite that eats first-stage thrips larvae and some broad and cyclamen mites; tolerant of cooler rooms and widely used in sachets as a preventive.A warmth-loving generalist predatory mite that eats thrips larvae, whitefly eggs and nymphs and broad mites, and can persist on pollen.A generalist-leaning predatory mite that eats spider mites and broad mites, survives on low prey or pollen, and tolerates warmer, drier rooms than Phytoseiulus.A mother plant is a female kept permanently in vegetative growth to supply cuttings, so a selected genotype can be propagated as clones indefinitely.A soil-dwelling predatory mite, formerly sold as Hypoaspis miles, that hunts fungus gnat larvae, thrips pupae and other small arthropods in the growing medium.Tiny parasitic wasps of the genus Aphidius that lay eggs inside aphids; the larva kills the host from inside, leaving a swollen tan mummy.A non-crop plant kept in the grow to host harmless alternative prey or pollen, breeding beneficial insects continuously so they are ready when pests arrive.The pest or disease level, set in advance, at which a grower takes a specific control action because waiting longer would cost more than acting.
