The cherry fruitworm (CFW) is a univoltine moth, native to the U.S., and whose larvae preferentially infest rosaceous and ericaceous fruits. CFW larvae have been confirmed infesting rabbiteye blueberries in Mississippi, and this typically northern pest’s appearance may represent a new State record. Without careful pest scouting after petal-fall, CFW-induced damage and fruit drop will often go undetected until berry losses become too severe for effective insecticide management. Scouting therefore is critical for managing CFW populations. Although the small and nocturnal adults of CFW can be elusive, there are excellent pheromone traps available for monitoring the activity of adult males, and by association, the destructive egg-laying females. Females oviposit on the calyx of blueberry fruit, much like cranberry fruitworms do. Upon eclosion, the larvae of CFW bore into fruit. It is at this stage of larval development that environmentally safe Bt insecticides are the most effective against CFW caterpillars. As larvae mature and become larger and more heavily sclerotized, they become harder to kill with Bt. However they are at greater risk of attack by predators and parasites because, unlike cranberry fruitworms, they do not erect silken webs around their feeding sites. Mature CFW larvae that are preparing to pupate avoid ground-based dangers by taking refuge in dead unproductive wood of blueberry bushes and other nearby vegetation. Removing old unproductive canes may reduce overwintering populations of CFWs and hence temper the severity of subsequent spring outbreaks.
The above information was written by:
Chris Werle1, Eric Stafne2, Blair Sampson1 and John Adamczyk1
1USDA-ARS Thad Cochran Southern Horticultural Research Laboratory, Poplarville, MS 39470
2Mississippi State University, Coastal Research and Extension Center, Biloxi, MS 39532
A longer article with a fuller description as well as photos is forthcoming in the July-Sept issue of the Mississippi Vaccinium Journal.