The use of insect netting on existing bird netting support systems to exclude spotted-wing Drosophila from a mature small-scale commercial highbush blueberry planting
This project investigated the feasibility of using 80 gram (.95 mm x .95 mm) insect exclusion netting on an existing bird netting support system to prevent Spotted Wing Drosophila (SWD) infestation in a commercial mature blueberry planting. Complete rows of the planting were covered with 60 gram insect netting, 80 gram insect netting, and standard bird netting prior to fruit coloring. The two netting treatments had mesh covered double entry vestibules for a defined entryway into the planting. Fruit samples were collected weekly and held in rearing cups in a lab for three weeks to determine SWD infestation levels in the fruit.
The system worked extremely well. In 2014, with the 80 gram netting, at most, only 0.53 percent infestation occurred in a 10 week harvest season. Unsprayed berries without exclusion netting had as high as a 60% infestation level in one sampling period alone. In 2015, using the 80 gram netting, at most, a 0.37% infestation was found over a 5 week harvest season. Sprayed berries without exclusion netting had as high as a 20% infestation level in an individual sampling period. The netting held up through 3 severe thunderstorms and 2 hail storms and we refined our attachment system for large scale deployment of large pieces of netting.
This system has great potential for small scale, organic, and no-spray blueberry growers and I believe the system can be used by raspberry growers as well. Approximately 750 growers were directly reached through 2 field days, 3 SWD workshops, and 4 state/regional conferences. Even more were reached through articles in trade journals. More presentations are on the calendar for after this grant is complete.