The palo verde beetle (Derobrachus geminatus) is a large longhorn beetle (family Cerambycidae) closely related to Derobrachus hovorei and sharing nearly identical biology and habits. Like its relative, it is one of the largest beetles in North America, with adults reaching 2.5–3 inches in length. The two species are often confused and collectively referred to as 'palo verde beetles' or 'palo verde root borers' in Arizona. Adults are dark brown to black with long, segmented antennae and spiny thoracic margins. They emerge during the summer monsoon season, are strongly attracted to lights, and are frequently encountered in yards, parking lots, and on sidewalks across the Phoenix metropolitan area and throughout the Sonoran Desert. Females lay eggs in soil near the base of host trees, and larvae bore into root systems where they spend several years feeding and tunneling. Host trees include palo verde (both blue and foothill species), mesquite, willow, cottonwood, and occasionally citrus and other ornamentals. The cumulative root damage from larvae causes gradual tree decline and can result in sudden structural failure of the tree. Both Derobrachus species are considered among the most significant insect threats to Arizona's urban and native desert trees.