You probably have seen them and not given them much notice, growing among your blueberry fruits. They look like something just went wrong in fruit development. These are mummy berries and they are actually part of a fungal pathogen, Monilinia vaccine-corymobosi. This is a blueberry disease!
Mummy berries are caused by a pathogen
Over the season mummies fall off of the plant and oversummer and overwinter on the ground. When conditions are just right in the spring, these bodies will germinate and can produce 650,000 disease-causing ascospores. The ascospores can re-infect your plants creating a disease cycle.
Control is not difficult for hobby blueberry growers
This disease affects leaves and affects the fruits when the pathogen is spread to the flower bloom, by wind or by insects. For commercial growers this can be a serious problem. For the casual blueberry grower it is much easier. Simply remove the mummies and throw them away. Also, check the ground to remove those mummies that have fallen.
For those of you interested in pathology, Jade Florence has an excellent article, Mummy Berry, in The Plant Health Instructor. If you are unsure if mummy berry is your problem, contact your local UGA Extension office for assistance. If you don’t have blueberries in your community garden, they are a great addition and easy to plant.