Moneilema gigas is a large, flightless, black beetle native to the Sonoran desert at elevations below 1500 metres.

[1] The front wings are fused forming a single, hardened shell.

Collectively - with 19 other Moneilema species - M. gigas is also known as the cactus longhorn beetle.

Larvae bore into cactus roots and stems, sometimes killing more susceptible individuals.

Cactus longhorn beetles resemble and mimic the behavior of noxious stink beetles in the genus Eleodes.