Aphid predators can provide long-lasting aphid control in greenhouses because they quickly setup breeding populations and don't fly towards light. They need soil or a soilless medium as part of their life cycle. Have not done well in rockwool. Also used in orchards and yards. General rate is 250 to get a colony established. Repeated releases establish them faster. May be used in conjunction with APHID PARASITE (aphidius colemani) APHIPAR. Preferred shipping UPS Next Day Air. Call for Best Rates.