Potential of Pyriproxyfen as a Quarantine Treatment for Codling Moth and Oriental Fruit Moth (Lepidoptera: Tortricidae)

Abstract

A juvenile hormone mimic, pyriproxyfen, had ovicidal effects on eggs of codling moth, Cydia pomonella (L.), and oriental fruit moth, Grapholita molesta (Busck). One-day-old codling moth eggs were more susceptible than 2-d-old eggs. Complete mortality of codling moth eggs was not attained at 10.0 ppm. At LC50 and LC90, 1-d-old oriental fruit moth eggs were less susceptible to pyriproxyfen than 1-d-old codling moth eggs. Older eggs of codling moth and oriental fruit moth did not respond to pyriproxyfen. Thirty-three codling moth eggs of 1,440 tested on nectarines survived an immersion in 10 ppm pyriproxyfen. Codling moth adults laid fewer eggs than unexposed adults when topically exposed to 25.0 μg per insect; they laid less viable eggs when topically exposed to 0.2-25.0 μg per insect. Exposure of codling moth and oriental fruit moth adults to pyriproxyfen residues (150-2,700 g/ha) did not affect fecundity but reduced egg viability in proportion to rate. Codling moth egg viability was reduced (97-100% mortality) by exposure of either adult females or males to 2,700 g/ha pyriproxyfen residues; viability of oriental fruit moth eggs was less affected than was codling moth egg viability. Exposure of both sexes of oriental fruit moth adults was more effective in reducing egg viability (94% mortality) than exposure of either sex alone, Exposure of adult females (92% egg mortality) was more effective than exposure of males (88% egg mortality) 1-4 d after treatment.