Cherry fruit flies trapped at NWMHRS
The first cherry fruit flies of the season have been trapped on Old Mission Peninsula and Leelanau and Benzie counties.
The first cherry fruit flies (CFF) of the season were detected in the NWMHRS trap line this morning (5 July). Positive trap catches have also been reported on Old Mission Peninsula and in Benzie County. Growers should refer to the following wing guide to accurately identify cherry fruit fly as many of the Ragolitis species appear similar.
Cherry fruit flies overwinter as pupae in the soil and produce one generation per year. Flies emerge for about a month, and peak emergence is in late June to early July. Seven to ten days after emergence, females deposit eggs in the fruit where hatching larvae immediately burrow in and feed. Most control strategies employ insecticides that target the adult stage during that 7-10 day window. If flies are trapped on-farm, but a regional trap catch was recorded earlier, the treatment should be timed based on the earlier regional capture to minimize the risk of larvae in the fruit. However, because population size influences trap catch, it is critically important that growers monitor their own farms for cherry fruit flies to help predict population size as well as duration of activity. Larvae mature in the fruit and then drop to the soil where they enter the ground, pupate, and start the next generation’s life cycle the following season.
Recent work has shown that a great deal of cherry fruit fly activity occurs after harvest providing a postharvest opportunity for management in sites with high populations. Preliminary research has shown that imidacloprid products such as Prey and Pravado work well at the post-harvest application timing seven days after harvest. This spray could be tank-mixed with the post-harvest chlorothalonil application for cherry leaf spot.
As mentioned above, chemical control of cherry fruit fly is focused on the adult, with the goal of preventing egg-laying and eliminating the risk larvae from the fruit. Refer to the table below (Gut et al.) for available treatments and application timing, refer to the E-154 Fruit Management Guide for more information and always read and follow pesticide labels carefully.
|Compound trade name||Chemical class||Optimal spray timing for cherry fruit fly begins||Residual activity||Effectiveness rating**||PHI|
|Guthion, Imidan (no Imidan on sweets)||Organophosphate||7-10 days after the first fly is captured||14+ days||E||7-15|
|Sevin||Carbamate||7-10 days after the first fly is captured||5-7 days||G||3-7|
|Asana, Warrior, Baythroid, Ambush||Pyrethroid||7-10 days after the first fly is captured||7-10 days||F-G||3-14|
|Delegate, Entrust*,||Spinosyn||Immediately after the first fly has been captured||7-10 days||F-G||0-7|
|Assail, Actara, Provado||Neonicotinoid||7-10 days after the first fly is captured||10-14 days||G||7-14|
|Altacor||Anthranilic diamides||Immediately after the first fly has been captured||10-14 days||G||10|
|Surround WP*||Particle Film, Protectant||Multiple applications before fly emergence||As long as thorough coverage of the tree canopy is maintained||G||0|
|Voliam flexi||Neonicitinoid and Anthranilic diamides||Immediately after the first fly has been captured||10-14 days||G||14|
|Leverage||Neonicitinoid and Pyrethroid||7-10 days after the first fly is captured||10-14 days||G||7|