Project code: PRR24-050
Project Leads
Justin Renkema – Agriculture and Agri-Food Canada
Tahera Sultana – Agriculture and Agri-Food Canada
Objective
To assess entomopathogens for controlling soil-dwelling stages of plum curculio and evaluate attract-and-kill methods using trap trees.
Apples (Malus domestica) are an important horticultural crop in Canada, with nearly 18,000 hectares planted, contributing over $284 million annually. However, plum curculio (Conotrachelus nenuphar), a small weevil native to North America, poses a significant threat to apples along with other tree fruits in the Rosaceae family including peach, nectarine, cherry, pear, plum, apricot, and blueberry. Plum curculio causes direct injury to developing fruits as adults and larvae feed on them, and egg-laying causes "D"-shaped scars. This damage can lead to fruit drop and wormy fruit, reducing marketable yield. Plum curculio was identified as a priority pest issue at the 2023 Canadian Pest Management Priority Setting Workshop. In this stakeholder-led prioritization process, Ontario tree fruit growers highlighted the need for an integrated management solution for this pest due to control challenges and the phasing out of its primary insecticide (phosmet, an organophosphate) by the end of 2025. The threat of plum curculio expands to other fruit-growing regions, including Quebec and Nova Scotia.
Beginning in 2024, researchers are developing an integrated strategy for controlling plum curculio in apple orchards using attract-and-kill methods with trap-trees, attractants, and biological control agents. Trap-trees, trees along orchard edges that are purposely baited with pheromones and feeding attractants and/or are attractive varieties and purposely planted are used to monitor incoming plum curculio populations and facilitate targeted treatment applications. Biological control agents, like entomopathogens, will target the soil-dwelling stages of plum curculio. Trap-trees and entomopathogens will be used to evaluate attract-and-kill methods for plum curculio. Different attractants, including baited trap-trees and a cultivars of apple that reportedly attracts plum curculio, and commercially available entomopathogens will be compared against standard practices using insecticides. Researchers will also examine entomopathogenic nematodes endemic to Ontario orchard soils to identify potential native biological control agents for plum curculio.
This project aims to enhance the knowledge and understanding of plum curculio and its impacts on orchards. The anticipated results will advance the integrated management of plum curculio by identifying effective alternative, non-chemical control tools. By characterizing native entomopathogens in Ontario orchards, a potential biocontrol agent could be discovered and pursued in the future. Project updates and results will be shared with growers and stakeholders through field demonstrations, publications, grower meetings, and conferences.