a1 Research Station, Agriculture Canada, Vineland Station, Ontario L0R 2E0
Studies have been undertaken with artificial food sprays in an attempt to increase the efficacy of predators against pests of corn (Schiefelbein and Chiang 1966; Carlson and Chiang 1973), alfalfa and cotton (Hagen et al. 1970), peppers (Hagen and Hale 1974), and potatoes (Ben Saad and Bishop 1976). It was believed that such sprays might attract predators into the crop ecosystem and keep them there particularly during periods when natural foods were in poor supply. Also, the availability of sufficient alternative food might induce these species to lay eggs even when natural host populations were low.
(Received March 13 1980)