Assassin bugs of many kinds are found in the Sonoran Desert and are generalized predators taking caterpillars and other mostly soft-bodied prey. Gardeners should encourage these insects by eliminating chemical pesticides and leaving some weedy vegetation in border areas.

Zelus bugs use an interesting technique for capturing prey: the tibiae on the first pair of legs are coated with sticky glue which helps hold prey while the sharp beak penetrates and delivers salivary poison. Z. tetracanthus has two spurs on the corners and two more on the dorsum of the thorax. Base color is often ashy gray.