First western cherry fruit flies set to emerge
LA GRANDE — The Oregon State University Extension Service in Union County is warning cherry tree owners of the emergence of the first adult western cherry fruit flies in the county.
According to a press release, the fly was expected to appear Sunday, June 16, in the La Grande area, and 50% of the adult fly population is expected to appear by July 1, and 100% adult fly emergence is expected by July 8. Eggs laid by the earliest emerging adults will hatch a few days before 50% of the adults emerge from the ground.
Initial spray applications should be made within the first week after emergence and then follow-up spray applications should be scheduled to control the flies until harvest. The insecticide product label will provide recommendations for spray application frequency and pre-harvest interval requirements.
"One spray application does not provide season-long CFF control," the release said. "Adult cherry fruit flies continue to emerge from the ground through late June and lay eggs into July."
Adults mature and begin laying eggs in the fruit. After about a week to 10 days, the eggs hatch into larvae that feed on the fruit for two to three weeks. At this time, larvae emerge from the fruit, drop to the soil to pupate and overwinter until this time next year
