Raspberry plant insects

Asked July 18, 2017, 4:56 PM EDT

I have a fairly new plot of raspberry plants and they are growing wonderfully. But I was just informed that there is a new pest in Minnesota that effects raspberries. They told me the way to know if you are infested is if there is small hole at the bottom tip of your berry. As that is where they crawl in and lay the eggs. My berries were fine until last week I now found a number of berries with a small hole in the bottom tip of the berry. Can you help me understand what is going on? My plants do not have any other symptoms. Are the berries still eatable? My friend does not eat any of hers that are infested. This would be a shame as I have a awesome crop this year.

Dakota County Minnesota

1 Response

Thank you for the question. Proper management of any pest or disease depends upon accurate identification. Holes in berries can be caused by insects, disease, or environmental factors. You will have to do more detective work to figure out what is going on. Perhaps the pest you heard about is spotted wing drosophila or SWD, an insect that resembles a fruit fly. You would not be able to see an entrance hole due to its tiny size. Read about SWD in the second link below and how to check for their presence. If you do have them and the problem is minor, you can still use the berries for jelly or wine. There are other insects that create holes in raspberries. Please read these publications and look for the signs and symptoms described. Most raspberry disease and insect problems can be managed by frequent picking of ripe berries, good garden cleanup at the end of the season, and managing the patch to promote good airflow to dry the plants after rain or watering.

Thank you for contacting Extension.