Spraying twice, ten days apart may be necessary for effective control. Plum curculio is a key early season pest on pome and stone fruits. If the flowering season is cool and dry, additional applications may be necessary. Insecticide for plum curculio should be sprayed at petal fall and first cover stage for hard fleshed fruits. If plum curculio infestation occurs and a rescue treatment is needed, organophosphates and … Spray for plum curculio in soft fleshed fruits, like peaches and cherries, at the shuck split and first-cover stages. Plum curculio control begins in the spring when overwintering adults emerge. Early detection and control are necessary to lessen its damages, which can even lead to economic loss for commercial growers. The adults may delay emerging until the weather is warm an… These conventional insecticides, such as organophosphates (OP) and pyrethroids, work primarily as lethal contact poisons on plum curculio … There are many insecticides available for plum curculio control, but their performance characteristics vary greatly compared to our traditional broad-spectrum chemistries. The best time to spray for control of this pest in in the spring when the adult beetles come out of the ground. Controlling Plum Curculio. Two additional applications at seven to 10 day intervals are best. Always read and carefully follow the instructions on the package when applying an insecticide. Conotrachelus nenuphar, plum curculio, or simply curculio is originally from Minnesota.It is an injurious pest in different North American states, as well as in some parts of Canada.