Blueberry fruit are shriveled with dry seeds on the outside

Asked July 13, 2020, 8:46 AM EDT

We have 18 blueberry plants of different varieties. We have noticed a cluster of berries with what looks like seeds around it, a hole in the berries and they are soft. What is causing this and what can we do? We use a drip system for watering, there is a netting over the entire fenced in area (we put the netting on when the berries start to turn blue and until the last picking). The photo showing more of the bush is an Elliott and I read in an MSU article that Elliott's are resistant to spotted wing Drosophila which we thought might be the problem.

Clinton County Michigan

1 Response

That is cranberry fruitworm. This is one of two moths that attack blueberries in Michigan. The cranberry fruitworm will attack multiple berries in a cluster and the cherry fruit worm usually only attacks single berries.These pests overwinter as pupa in the soil. The adults emerge during bloom and lay their eggs on the green fruit. It is seldom a significant backyard pest in small blueberry plantings.

Almost every resource we have is focused on commercial production. Here is a link to our blueberry insect pests of Michigan https://www.canr.msu.edu/blueberries/pest_management/insects.

Next year you can apply an insecticide to the green fruit immediately after bloom

The pest has already past and you are see the worms and there frass on your