Cactus Longhorn Beetle (Moneilema gigas) normally feeds on chollas and prickly pear cacti, and is known to feed on saguaro seedlings. Larvae bore into cactus roots and stems, sometimes killing more susceptible individuals. Adults also feed on the surface of cacti. They are most active during mid or late summer, with the adults typically emerging during the summer monsoon season. Like many flightless beetles, these beetles have limited wing musculature with a rounded abdomen and thorax, similar in appearance to a number of other flightless desert beetles. Cactus longhorn beetles resemble and mimic the behavior of noxious stink beetles in the genus Eleodes.