Anthracnose (Image 1) is a fungal disease that's especially common in hot, humid climates. The fungus causes brown, sunken spots on the fruit and often causes the plants to die. The frequent occurrence of this disease in hot climates is why so many people prefer to treat strawberries as annuals and to start each year with new, certified disease-free plants.
Other diseases include crown rot, light blight, fruit rot and leaf spot. The best line of attack is prevention: keeping the plants stress-free by proper watering; not working in the field when the plants are wet (because diseases spread more easily among wet plants); keeping weed competition down; and choosing the right plants for your climate.
If you decided to use pesticides, be sure to start with the least toxic pesticide possible, and follow all label directions. Strawberries are also sometimes bothered by pests such as aphids. Again, choose the least toxic approach to controlling pests. One option is to introduce beneficial insects, such as ladybugs (Image 2), to your garden to control pests.