I’m afraid spotted wing drosophila are loving our humid weather! On June 8 we collected red raspberries from a commercial farm. We chose berries that looked over ripe. Out of 19 berries we reared 26 SWD pupae. That’s a whole lot of SWD so early in July! We set out traps to catch adult SWD at 3 berry farms in RI, and at all 3 we have caught SWD adults.
I hear one local blueberry grower found a fruit fly larva (most probably SWD) in a blueberry today. And Rich Cowles, from the CT Ag Experiment Station reported he found SWD larvae in an early variety of blueberry picked on 7/11/15.
If you are going to spray your blueberries or raspberries with insecticides, it is time to start spraying.
Whether you spray or not, it is important to harvest your berries as completely as possible. Leaving ripe berries in the field allows more SWD to develop and generate more SWD.
See this link for more information on SWD management, including pesticides:
It may be helpful to add 1-2 pounds of sugar per 100 gallons of spray mixture. This encourages SWD to feed and ingest insecticide. This doesn’t work with pyrethroid insecticides such as bifenthrin and Mustang Max.