A field assessment of the effects of insecticides on the beneficial fauna of strawberry

In field experiments, insecticides used against pests on strawberry showed differential toxicity to the major groups of beneficial arthropods. Pirimicarb and heptenophos had no significant effect on spiders, staphylinids and anthocorids, or on hymenopteran parasitoids. Chlorpyrifos, demeton-S-methyl and the pyrethroids cypermethrin and bifenthrin reduced populations of beneficial arthropods in some experiments. Some of the variation in toxicity between experiments may have been due to differences in the availability to predators of refugia, where predators could escape contact with spray or residues. (C) 1997 Elsevier Science Ltd.