Bioassays of insecticide drift from air assisted sprayers in an apple orchard

Abstract

SUMMARYInsecticide drift from an air assisted sprayer was measured on two occasions in an orchard in Cambridgeshire. Bioassays with two day old larvae of Pieris brassicae (cabbage white butterfly) showed similar effects from Cypermethrin and carbaryl (used as a fruit thinner). Both compounds gave 50% larval mortality at 20-25 m and 10% mortality at about 50 m. The effects of wind speed and shelter are considered, and the results are discussed in relation to the effects of drift from tractor-drawn hydraulic sprayers.