Increased numbers of earwigs (<i>Forficula auricularia</i>) in kiwifruit orchards are associated with fewer broadspectrum sprays

Abstract

European earwigs are sensitive to the residues of broadspectrum insecticides More earwigs are found on organicallymanaged than on conventionallymanaged kiwifruit orchards Since 2007 there have been changes in insecticide use on kiwifruit orchards In particular the broadspectrum insecticide diazinon was replaced by socalled reducedrisk insecticides In the current study earwig numbers were measured in nine conventionallymanaged and seven organicallymanaged orchards for 4 years (200607 to 200910) Numbers of earwigs on orchard blocks under organic management did not differ between years and were initially higher than on conventionallymanaged orchard blocks There was a trend for earwig numbers to increase on conventionallymanaged orchard blocks Earwig abundance decreased by approximately 60 with each spray application after allowing for differences between years