Proper Placement of Predatory Mites
The placement of sachets containing predatory mites isimportant to ensure their effectiveness. The photo on top shows what not to do(i.e. donít place the sachet in direct sunlight) and the photo on the bottomshows what to do (i.e. place the sachet within the crop canopy).
Predatory mites have become a mainstay of biological controlprograms in greenhouse edible crop production. Depending on the type ofpredatory mites you have that may control thrips, mites, whiteflies. Sachetsare available that provide a slow release source of predatory mites (forexample: Cucumeris or Swirskii) for up to 3-4 weeks. However,placement of the sachets has a large impact on the survival and hence their effectiveness.The sachets should be placed within the crop so the predatory mites can leavetheir exit hole and directly have access to the crop you are trying to protect.The sachets should also be kept protected from direct sunlight. In a study atthe Vineland Research and Innovation Centre, sachets hung in an exposed environment(i.e. above the plant canopy) had much lower numbers of mites emerging thansachets placed within the plant canopy. Inaddition, placing the sachet so that the bottom is touching most substrate willalso increase the longevity. The beneficial mites need high humidity to hatch.For more information, see the excellent article: 4 ways youíre accidentally killingyour predatory mites.
Neil MattsonAssociate professor and greenhouse extension specialist, Cornell University
Neil Mattson is an Associate Professor and Greenhouse Extension Specialist at Cornell University. He has an appointment in research, extension, and teaching. He researchers strategies to optimize floriculture and vegetable crop production while reducing energy, fertilizer, and water resources. He directs Cornell’s Controlled Environment Agriculture group which develops lighting and greenhouse control strategies to maximize hydroponic vegetable production.