THE EFFECT OF CYPERMETHRIN ON THE FEEDING OF MUSTARD BEETLES PHAEDON-COCHLEARIAE (F)

Cypermethrin deposits on sprayed (3, 6, 9, 12 and 15 g ha‐1) radish leaves caused a significant antifeedant effect on third instar larvae and adults of mustard beetles. There was a significant inverse relationship between feeding and dose for both stages. In the case of adults on deposits of 1, 3 and 6 g hafeeding was reduced by 60–75% but no mortality was recorded. Much less uniform feeding was associated with higher application rates (9, 12 and 15 g ha‐I) with low mortality at the two highest doses. The mean areas of the individual holes eaten by larvae or adults in either control or treated leaves, did not differ significantly. The number of holes eaten was negatively related to application rate. The antifeedant effect was observed with low concentration of both technical and formulated cypermethrin. Copyright © 1990, Wiley Blackwell. All rights reserved