Once you notice adults on the wing, it is usually not too difficult to find buckeye caterpillars hiding in and around its host plant (plantain) in agricultural areas, disturbed areas, canals, or along waterways near St. George, Utah; Mesquite, Nevada; Las Vegas, Nevada; Cottonwood, Arizona and in other locations in Arizona and Southern California.  Buckeye caterpillars can also be found on snapdragon near desert creeks and dry gullies.