The UMass Vegetable & Fruit IPM Program trapping network has yielded no positive trap captures to date. At this time last year we were catching small numbers so the onset of activity is about a week late by comparison. Some nearby states have reported single captures in a very few locations, but no one has had significant and sustained captures yet.
What does this mean for you? Having apple cider vinegar or fermented yeast bait traps (see Monitoring page for recipes) at your farm near field with ripe or ripening fruit is a good idea. Check the traps frequently to determine when SWD become active on your farm. Ripe or ripening fruit PLUS positive trap captures (see ID page to be sure they are SWD and not ordinary fruit flies), is the trigger to start your spray program. See Management page for recommended tactics. Don't forget, spraying alone will not alleviate the problem. Frequent and thorough harvest, not allowing cull fruit to drop to the ground (or cleaning it up if it does), and getting harvested fruit into the fridge are all essential elements of an effective SWD management program.
Another recommended practice is to pull a subsample of fruit you are harvesting, at least a couple of times per week, and place the fruit in salt water to see if any SWD larvae emerge. See Extraction Directions for instructions. Collect ONLY sound marketable fruit for this test. Damaged fruit may have larvae from other fruit flies and be difficult to identify as being SWD or not. Doing this regularly will help you determine if your management/spray program is working and might help pre-empt complaints from customers.
