Elevated esterase activity in resistant tufted apple bud moth, Platynota idaeusalis (Walker) (Lepidoptera: Tortricidae)

Abstract

1. Esterase activity in the tufted apple bud moth was measured spectrophotometrically by the hydrolysis of α-naphthyl acetate. 2. Resistant populations from both laboratory and field exhibited significantly greater esterase activity than did the respective susceptible populations. 3. The resistant laboratory population had significantly higher esterase activity than the resistant field population, suggesting that this field population contained a mixture of resistant and susceptible individuals.