There are some new developments in biocontrol of Spotted Wing Drosophila that may be of interest to current berry and fruit growers. Most of the proposed SWD control strategies (physical, chemical and biological) have focused on reducing the adult population of SWD, with variable success.
A more promising target for SWD biocontrol may be the SWD reproductive cycle, which can be more accessible. In the case of soft berries like raspberries, this cycle is completed in the ground of growing beds. And a beneficial nematode (Steinernema feltiae) that is commercially available has been shown to be effective at parasitizing and killing SWD larvae and pupae in the soil. This potential Sf effectiveness for SWD control has been validated by laboratory and field research with blueberries at MSU: Nematodes vs. SWD - Good Fruit Grower
My 6 year experience with heavily SWD-infested raspberries in western NC has been very positive: Rapid SWD reductions on harvested berries over the first 2 years of Sf nematode applications (2016, 2017). And then no SWD-infested berries detected from 2018 to the first harvests of 2023.
Of course, having a biocontrol method that is more effective than the chemical alternatives would be a real plus for organic berry growers! And an extension to SWD control in hard fruits may also be possible.