Eight lacewing (Chrysopa earned) larvae per greenhouse snapdragon (Antirrhinum majus), released 4 at a time twice during 8 weeks effectively controlled aphids (Myzus persicae). Two initial sprays of malathion and nicotine sulfate 1 week apart followed by release of 4 lacewing larvae per plant also were effective. Flowers produced under chemical or biological control systems were equal in quality. Lacewing larvae in a 21°C greenhouse required a week longer to effectively control aphids than those in a 24°C greenhouse.
Received for publication on January 19, 1973. Contribution No. 517, Department of Horticulture and Forestry, Kansas Agricultural Experiment Station, Kansas State University, Manhattan.
Graduate Student and Research Horticulturist, Floriculture, respectively.