Abstract
In the apple orchards of Nova Scotia DDT, azinphos-methyl or lead arsenate control the winter moth, Operophtera brumata (L.). DDT, even at a low dosage, is detrimental to predators but not to the phytophagous mites Bryobia arborea M. & A. and Panonychus ulmi (Koch); azinphos-methyl is toxic to B. arborea but not to P. ulmi; lead arsenate is of low toxicity to both the phytophagous mites and predators but effective in control of the winter moth when applied against the maturing larvae.