Laboratory bioassays and field evaluation of insecticides for the control of Anthonomus rubi, Lygus rugulipennis and Chaetosiphon fragaefolii, and effects on beneficial species, in UK strawberry production

Abamectin, Beauveria bassiana, buprofezin, pymetrozine, tebufenpyrad, acetamiprid and the coded product 60145 were tested in laboratory bioassays to determine their effects on the strawberry pests Anthonomus rubi, Lygus rugulipennis and Chaetosiphon fragaefolii and on the predatory species Phytoseiulus persimilis and Chrysoperla carnea. Abamectin, acetamiprid, tebufenpyrad and 60145 were the most effective insecticides against the pests. These four compounds all had some effect on P. persimilis, but acetamiprid was the least toxic (63% mortality after 48 h). Abamectin, tebufenpyrad and 60145 had no detectable effect on C carnea larvae, whereas acetamiprid caused 38% mortality after 72h. In field experiments where acetamiprid, 60145 and abamectin were tested against C fragaefolii, acetamiprid was very effective at reducing numbers of the aphid. Naturally occurring beneficial anthocorid species were reduced in number but not eliminated in the acetamiprid treatment. In field tests acetamiprid, abamectin and thiacloprid were less effective against L. rugulipennis than the industry standard chlorpyrifos. Reductions were small but statistically significant in the acetamiprid and thiacloprid treatments. Fruit damage was also reduced in these treatments. There was no detectable effect of these insecticides on naturally occurring beneficial species. (C) 2004 Elsevier Ltd. All rights reserved.