For Thrip Control in High Humidity Conditions:
Thrips Predator Mites

   Normally, Thrips Predator Mites (Amblyseius cucumeris) are most effective under conditions of 70-85% humidity, against all species of Thrips. They will also eat an occasional Spider Mite, and other small pests. However, reports have been poor in low humidity environments, so use these predators in greenhouse and other interior locations with high humidity levels only.

   Application: Simply sprinkle your Thrips Predator Mites onto plant foliage or on rockwool blocks in infested areas; they'll do the rest. Use 100-500 per plant; or 200,000 per acre, repeated every 2-3 weeks until established.

   Handy Hint: Insect screening material can be stretched over air intakes to filter many pests out, but you may need larger exhaust fans because of the air restriction. Check with your greenhouse or nursery supplier.