You might need to take those effected berries off by cutting and putting them in a plastic trash bag, don't mulch them..........go to the lawn & garden store and see which fungicide will work with strawberries. Don't touch other parts of the plants or in your garden until you have washed your hands. Is this a sunny spot for the stawberries...they also needs lots of ventilation and good drainage....it is suggested that you use black matting down..........or mulch well in the spring. there should be good spacing between the plants.