Field Evaluation of Insecticides for Control of the Alfalfa Blotch Leafminer and Its Effect on Alfalfa Yield in Prince Edward Island12

Abstract

Toxicity of three pyrethroid, six organophosphorous, and three carbamate insecticides against adults and larvae of Agromyza frontella (Rondani) were evaluated in alfalfa plots in the field. Most of the insecticides reduced alfalfa blotch leafminer damage significantly, but the treatments did not result in significant yield increases. The best control of leafminers resulted when insecticides were applied at the time of peak adult populations and the first sign of larval mining.