Effects of amitrole (3-amino-1,2,4-triazole) on the common earwig Forficula auricularia L. (Dermaptera: Forficulidae)

Abstract: The common earwig Forficula aricularia L. (Dermaptera: Forficulidae) plays an important role in the natural control of orchard pests such as woolly apple aphid (Eriosoma lanigerum Hausmann) and pear sucker (Psylla pyri L.), but the use of pesticides may hinder its effectiveness. We therefore investigated the role of pesticides on the survival and reproduction of earwigs. In this paper the results are presented of laboratory tests with amitrole (3-amino-1,2,4-triazole), a herbicide that is used extensively in Dutch orchards. Females that were exposed to amitrole in autumn did not suffer extra mortality, but eggs that were laid in the following spring after the exposed females had overwintered did not hatch. So far it could not be shown that the same effect occurs in an orchard situation but the effects found show that we should be aware of the delayed impacts of pesticides on this predator.