An aerial dispersal system was developed for inundative release of insect eggs, Anagasta kuehniella (Zeller) and Sitotroga cerealella (Olivier), parasitized by Trichogramma minutum Riley. The equipment was used successfully in field tests over a 4-year period (1982–1985) in a coniferous plantation forest near Hearst, Ont. The release equipment consisted of simple electrical components, mechanical components from a small grain planter, and a centrifugal slinger used for aerial seeding of jack pine. The equipment was mounted on a Bell® 47 helicopter, flown at about 25 m above the ground. A swath width of 15 m was attained using this system. Application rates ranged from 12.3 to 263.0 g ♀ ♀ parasitoids per hectare (0.6–25 × 106 ♀ ♀ parasitoids per hectare) during the 4 years of tests.