There are some important cultural controls that growers can adopt to minimize the buildup of populations.
- The highest risk varieties are those that are harvested later and varieties with thinner skins.
- Remove damaged, overripe, or rotten fruit when present
Chemical control measures are directed against the adults; there are no effective controls for larvae in the fruit.
- If significant economic damage is being observed, weekly spray applications may be needed. A few damaged grapes do not warrant a field spray!
- When using organic materials, shorter spray intervals will be needed because of the shorter residual life of botanical insecticides.
- As always, insecticides* with a different mode of action should be rotated in order to delay the development of insecticide resistance. The selection of insecticides for SWD control should take into account other pests present, harvest date, re-entry restrictions, as well as the potential impacts on existing IPM programs, beneficial insects, and the environment.
- The following are effective:
- Carbamates (IRAC Class 1A= carbaryl, Sevin)
- Organophosphates (IRAC Class 1B = malathion; phosmet; Imidan)
- Pyrethroids (IRAC Class 3 = Brigade; Baythroid; Danitol; Mustang Max; Tombstone; (be wary of induction of secondary pests))
- Spinosyns (IRAC Class 5 = Delegate; Radiant)
- For details please see Virginia Tech Pest Management: http://pubs.ext.vt.edu/456/456-017/Section-3_Grapes-1.pdf
- Organic (OMRI approved) options:
- Pyrethrins (IRAC Class 3 = PyGanic (be wary of induction of secondary pests))
- Spinosyns (IRAC Class 5 = Entrust)
- Grandevo 30 (Chromobacterium IRAC Class unknown)
- Surround 95WP3 (kaolin; IRAC Class unknown) has shown efficacy, especially on red grapes, and may be a good choice as a first response or in a low-pressure situation. Surround may impact harvest parameters.
*Remember to follow the label restrictions and rotate chemical classes to avoid resistance development. If this pest is present, the level of control will depend on the size of the SWD population, timeliness of application, coverage of fruit, and product effectiveness.