The squash bug (Anasa tristis) is one of the most common and troublesome pests attacking squash and pumpkin plants. Both nymphs and adults suck sap from the leaves and stems, apparently at the same time injecting a toxic substance into the plant causing a wilting known as Anasa wilt of cucurbits. This closely resembles bacterial wilt, a true disease. After wilting, vines and leaves turn black and crisp, and become brittle. Small plants are killed entirely, while larger plants have several runners affected. Squash bugs are often found in large populations, congregated in dense clusters on vines and unripe fruits. Sometimes no fruits are formed.