From: Doug Pfeiffer, Fruit Entomologist
I wrote earlier about the likely threat of spotted wing drosophila (SWD), an invasive pest of fruit that we found in a Virginia berry plot in June. It has subsequently been found in the three other Virginia trapping locations, and has spread north to collection points in Pennsylvania, New Jersey, Connecticut and Rhode Island.
This is a much more important pest than the Drosophila species we are used to dealing with. This species attacks ripening and ripe fruit, not restricted to soft, overripe fruit. The female has a large, saw-toothed ovipositor, used to cut through the fruit skin to lay an egg. A berry grower just reported almost 100% infestation by SWD.
In the Virginia Vineyard web site, I have already updated the html version of our pest management recommendations to address SWD (the pdf version is updated only once a year – while revisions are already submitted, it will be some time before the posted version reflects the changes). It is critical to use insecticides that have a short pre-harvest interval (PHI). PHI’s of 0-3 days are generally acceptable. PyGanic, a natural product has been successful, but should not be used excessively during the season because of concerns for resistance development.
For more information on SWD, visit: http://www.virginiafruit.ento.vt.edu/SWD.html or search in Google using the term: SWD Virginia Tech
More later, Doug