I saw some trees covered with netting last week and that got me thinking about two serious fly pests of cherries in the valley; western cherry fruit fly and spotted wing drosophila. These two are responsible for most of the worms in cherries if untreated (very unpleasant).
Cherry fruit fly is about the size of a housefly and has an “ogopogo” pattern on the wing. The adult fly comes out of the soil in June and lays eggs a week later on ripening cherry fruit. The eggs hatch into maggots that feed inside the fruit. The mature maggots come out of the fruit and drop into the soil to form a pupa which will spend the winter in the soil and the adult will come out again the next spring.
Spotted wing drosophila (SWD) is a vinegar fruit fly. It looks like fruit flies you find around rotting bananas. Spotted wing drosophila is different from other vinegar flies because the female has developed an impressive saw-like egg laying organ that allows it to cut into ripening fruit to lay its eggs. Other vinegar fly females do not lay eggs in ripening fruit. The males have black spots on the wing hence the name. SWD showed up in the Okanagan in 2012 and can cause millions of dollars in fruit loss to our cherry growers. SWD also attacks other soft fruit and berries.
If you have backyard cherry trees and have had worms in the fruit, it could be due to attacks by these flies. Please be a good neighbour and get your trees treated. See the following links for additional information: Spotted wing drosophila and A guide to managing tree fruit pests in the home garden
Bugs N Stuff 