Crop specific strategies for control of SWD in berry crops

Successful control of SWD in berry crops requires a combination of management practices and insecticide application. Here are some specific things for berry growers to consider when developing a management program for SWD on your farm.

All berry crops:

  • Calibrate your sprayer. There is no room for error, especially when spraying close to harvest.
  • Strip bloom and fruit buds from new plantings which won't be harvested.
  • Keep weeds and vegetation mowed or otherwise controlled in and around the field.
  • Cool fruit as soon as possible after harvest and keep it cool.
  • Develop a system for managing waste fruit. Whenever possible, fruit should be removed from the field. At the very least, unmarketable fruit should be picked off the plant and dropped in alleys and crushed. Fruit which is discarded from coolers or pack sheds should be sealed up in plastic bins or bags, or buried daily at least two feet deep.
  • Get set up to monitor for SWD damage by floating fruit in salt water to look for larvae. For information on the "salt test" see www.ontario.ca/spottedwing under monitoring.
  • Pay attention to nighttime temperatures. Warm nights lead to more SWD activity and more rapid SWD development. Adjust harvest and spray schedules accordingly.

June-bearing strawberries:

Strawberry harvest could be over before spotted wing drosophila populations build up enough to cause damage. Pay attention to SWD trap catches in the area. If SWD adults are being trapped while ripe fruit is being harvested, an insecticide might be needed. Late season varieties could be at risk, depending on how early SWD populations develop. Encourage clean picking, and send your workers in to clean up fields after pick-your-own harvesting. Renovate as soon as harvest is complete. A post-harvest insecticide can be applied if other susceptible crops (i.e. raspberries) are close to your strawberry fields.

Summer red raspberries:

  • Trellis the crop to facilitate clean picking.
  • Begin weekly insecticide applications when SWD are found in traps in your region and fruit is turning colour.
  • If preharvest intervals permit, adjust your harvest schedule to pick every second day instead of every three or four days.
  • The most important management strategy for raspberries is clean and frequent harvest. Remove fruiting canes as soon as possible after harvest.

Day-neutral strawberries:

  • Begin insecticide applications when SWD are found in traps in your region and fruit is turning colour.
  • Continue on a 7-10 day schedule.
  • Harvest day-neutral strawberries on a regular basis, even when the picking is light.
  • Overwintered day-neutral fields are more at risk compared to new plantings, because extra foliage and plant debris in older fields make clean harvest more difficult. As you drop fields at the end of the season, mow them (unless you are going to harvest them next year) or do something to destroy fruit.

Blueberries:

  • Begin weekly insecticide applications when SWD are found in traps in your region and fruit is turning blue. On pick-your own farms you will need a way to keep the public out of fields that have been recently sprayed. Some growers close their farm for 1-2 days a week for pest control.
  • Encourage clean picking.

Fall-bearing raspberries:

  • Trellis the crop to facilitate clean picking.
  • Begin weekly insecticide applications when SWD are found in traps in your region and fruit is turning colour.
  • Laterals from buds at the base of primocanes often produce berries ahead of the main crop. These fruit should be harvested or stripped from the plants. The most important management strategy for raspberries is clean and frequent harvest.
  • Don't grow more fall-bearing raspberries than you can harvest on a regular schedule.

Organic berry crops:

Two of the insecticides (Entrust SC and Pyganic) registered in 2013 are accepted by most organic certifiers. However, residual efficacy of Pyganic is very short, and repeated use of Pyganic has already resulted in resistance in California. Alternate these two products to reduce the chance of resistance developing. In organic situations, sanitation is even more important. Remove all unmarketable fruit from the field.

Research to identify native natural enemies of SWD is underway in Ontario and other production areas in Canada and the US. Other management strategies including exclusion netting or floating row covers, mass trapping, and the efficacy of different pest control products, are currently being evaluated.

With just a year of experience with this new pest, management practices are evolving. The latest information on identification, monitoring and management of this invasive new pest can be found at www.ontario.ca/spottedwing.


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca