Published online by Cambridge University Press: 31 May 2012
Four insect developmental inhibitors were tested against different stages of the apple maggot, Rhagoletis pomonella (Walsh). ZR515 was the most effective compound, completely inhibiting adult development from larvae and pupae treated at concentrations of 10 μg. Larvae were more susceptible than pupae. Sensitivity declined as pupae aged. Dissection of puparia showed a pupal/adult intermediate, usually with some adult characters developed in the thoracic region. ZR512 inhibited adult movement from larvae or pupae exposed to concentrations of 1.0 mg whereas R20458 gave inhibition of adult development at 10 mg concentrations. RO 20-3600 inhibited adult development from larvae exposed to concentrations of 10 mg. ZR515 and ZR512 applied to fruit had little effect on larval development but numbers of adults emerging from pupae from treated fruit were reduced. Adults from all tests produced viable eggs in the following generation.