Grapes:
Spotted Wing Drosophila (SWD): The spotted wing drosophila is an invasive fruit fly which can infest sound ripe thin-skinned fruit. The SWD female has a saw-like ovipositor which she uses to literally saw through healthy skin and deposit her eggs, which develop into small maggots. At this time of year each generation takes slightly over 1 week to complete. Each female can lay about 300 eggs over her lifetime, and given the time of year it is, we will probably see 3-5 more generations by the time grapes are harvested. Over the past several years we have monitored SWD in vineyards during August through September. A well-known link exists between high populations of native fruit flies and the prevalence of late season sour rot in grapes. What we don’t know is how the prevalence of SWD might be able to aggravate or help increase the late season populations of native fruit flies, or if the total fruit fly complex (native and invasives) is higher because of the presence of SWD. [Read more…]