Presented below is a photomicrograph of a squash bug's mouthparts, which are used to suck the juices out of plants such as pumpkins, melons, and cucumbers. This digital image was captured with the DXM 1200 ACT-1 control software in single-image acquisition mode utilizing apodized phase contrast illumination.

Squash bugs, Anasa tristis, are "true bugs" that utilize their piercing sucking mouthparts to remove plant juices. They attack cucurbits (squash, cucumbers, and melons) throughout Central America, the United States, and southern Canada, with a preference for squash and pumpkins. They are generally found on well-established plants as opposed to being a pest of seedling plants.

The adult measures about 0.6 inch (1.5 centimeters) in length and is dark grayish brown. In many cases the edge of the abdomen is marked with alternating gold and brown spots. They are long-lived, surviving an average of about 75 to 130 days, depending on availability and quality of food.

The squash bug damages plants when large numbers of them occupy a plant and suck out the sap. They also secrete highly toxic saliva into the plant, which damages plant tissues. The foliage is the primary site of feeding but they also feed on fruit. The foliage wilts, becomes blackened, and dies following feeding; this malady is sometimes called "anasa wilt." Often an entire plant or section of plant perishes while nearby plants remain healthy. The amount of damage occurring on a plant is directly proportional to the density of squash bugs.