A turbocharged, invasive vinegar fly from Asia — that unlike its American cousins prefers ripening fruit to rotten — is causing growing turmoil for those who farm Michigan's signature fruit crop, tart cherries.
The spotted wing drosophila — called SWD for short by researchers and affected farmers — only made its way to Michigan around 2010, after having been found in California the year before. The tiny vinegar fly (don't call it a fruit fly; that's similar but a little different) only a few millimeters in length, likely made its way in cargo ships from its native range of eastern Asia. As it doesn't fly far, it probably got a lift on human transportation to move from the West Coast to Michigan and other states where it's now found.
SWD are fond of all kinds of thin-skinned fruit. And it was only about two years ago that it became apparent to tart cherry growers that this was going to be a problem.
Unlike native types of fruit and vinegar flies, which require mushy, rotting fruit, the SWD has an ovipositor — a tube-like organ through which female insects lay their eggs — with a serrated edge, enabling it to cut through not-yet-ripe fruit.