You may not remember all the way back to the start of this growing season, but the warning was put out early to watch out for some serious pestering by the spotted wing drosophila fly. That’s the invasive vinegar fly that’s been causing trouble ever since it was first spotted in California in 2008. It’s been a major problem in the Pacific Northwest, and has also caused problems in Pennsylvania. The SWD–as it’s become known–is real tourble, since the females can lay their eggs in unripened fruit. August is always a scary time with these things, since there’s been SWD infestations of fall blackberries and raspberries, in addition to peaches, plums, cherries, strawberries, and grapes late in the season. [image via fruitgrowers news]
You really need to be watching out for the spotted wing drosophila fly so that they can be killed off before building up a big population. The SWD is particularly loathsome for targeting young fruit over rotting fruit. There are lots of pesticides that yo can use to go after the pest, but we kind of hate how the SWD has become responsible for an increased amount of sprayings. We don’t like the chemicals, and it’s an added expense to the farmers. And, eventually, the consumers.
The SWD is a pesty even by pest standards. You can find them swarming over orchards that don’t even have crops. They’ll settle into trees that haven’t carried fruit for over a year. They seem to always find new fruits that they haven’t gotten around to sampling. (The vineyards are always dreading the day when the SWD discover grapes.) The best baits for SWD also bring in enough other bugs that you might be better off not leaving anything out.
It’s pretty terrible to think of having SWD hanging out during the winter. The survivors are mostly adult females, and they can lay up to 600 eggs in fruit. Those eggs can hatch in as quickly as two hours, with the larvae feeding on the fruit for anywhere from three to thirteen days. The best management remains getting as much fruit cleared out as possible. Not just the harvesting, but also clearing out any fruit on the ground or that’s failed to drop from the trees. That–and some eternal vigilance–is your best bet for getting through this time of year with minimum SWD carnage.