Hello Kaye, 

Sorry to hear about your raspberries. Fortunately, the UMN Extension has a helpful article about spotted wing drosophila and methods for control. Here is the link: https://extension.umn.edu/yard-and-garden-insects/spotted-wing-drosophila

It is important to harvest ripe or old fruit so that it doesn't remain in the garden for extended periods of time. Make sure to clean up any fallen raspberries too, and do not compost or bury the infested or fallen fruit. Put it in a sealed plastic bag in the trash. 

For next year, you may wish to consider using netting to protect the raspberries from SWD. The UMN article also includes steps for making your own SWD trap using apple cider vinegar. 

There are insecticides that you could use, but once the fruit is infected, the insecticides will not prevent SWD. Insecticides should be used to target the adults, before they lay eggs. More information can be found in the link under the "Using Insecticides" section. 

If you use an insecticide, make sure to always follow the pesticide label directions attached to the pesticide container you are using. Be sure that the plant you wish to treat is listed on the label of the pesticide you intend to use. Remember, the label is the law.

Good luck!