For the maritime NW, mummy berry infection of blueberries can result in up to a 90% loss of fruit, depending on temp and rainfall. This pest risk model: https://uspest.org/risk/models
programmed with your location, can give you an idea of when berry ascospores are initiating infection.
Sanitation is the primary method of control, requiring yearly replacement of mulch or yearly vacuuming up of litter before the acospore infection window opens. Sanitation usually helps to reduce my mummy berry losses to about 15%. Without sanitation, depending on the year, I could lose (and have lost) 90% of the crop!
This year I am adding Regalia, licensed for use on mummy berry, to my control options. Using the infection model for my location (you can program to match your closest weather site), I see that the infection risk has begun and I am spraying every 7-10 days to see if I can further lower my blueberry losses.
This https://uspest.org/risk/models also has infection risk data for apple maggot, apple and pear scab, and various blights and mildew.
Very interesting to track all the (non-human!) infection patterns.