Watch for buildup of colonies of aphids on the underside of the leaves. Use a suggested insecticide if colonies appear. Pickleworm is the larvae of a moth that lays eggs in the squash flower. This larvae damages the young developing flower and fruit. Control insects by using a suggested insect control method.
Powdery mildew is a fungus that attacks the foliage during cool, damp periods.
It is commonly seen in the fall. The surface of the leaf takes on a dusty grey color. Use a suggested fungicide to control this disease. Leaf spots such as Anthracnose and Septoria will quickly defoliate a plant. The diseases are caused by a fungus and are controlled by making foliar applications of a suggested fungicide.