Almost everyone enjoys the sweet flavor of raspberries — including bugs. Although raspberries don't typically attract as many insects as other fruit plants do, there is still a few that like to feed off the red berry, including the cane borer and the tarnished plant bug. Insects can cause serious damage to the plants, destroying their berries and making them inedible for humans. If the infestation is bad enough, the bugs can even cause the plant to die. There are a few techniques you can employ to keep the pests away from and off your raspberry plants.
Remove any wild plants located near your raspberry plant. Wild plants attract insects, which eventually venture over to your raspberry plant. Cut down the wild plants and pull or dig them up from their roots. Monitor the area around your raspberry plant to ensure it stays free of wild plants.
Look at the canes on your raspberry plant. If you see a slight swelling that contains two rings, your plant is being attacked by cane borers. To get rid of them, cut the cane just under the lower ring and burn it to kill the borer. Continue to monitor your plant for any additional signs of borers, and cut the cane off as soon as you see them.
Spray a pesticide on the plant to eliminate the insects, if the above techniques do not work. Ensure that the pesticide is safe to use on fruit. The timing of the application depends upon which pesticide you use. For instance, some products should be applied to the plant only before it produces berries. Read the instructions on your particular pesticide for the recommended timing of its use.
Planting your raspberries away from corn and hay fields may help to prevent bugs from attacking them, as many breed in such fields.