Arizona Red Spotted Purple
Limenitis arthemis arizonensis
This butterfly was photographed along Sycamore Creek, Mazatzal Mountains, Maricopa Co., Arizona and is also hosted at Wikimedia. 13 Apr. 2008.
This is a butterfly of riparian corridors in the Sonoran Desert where its required food plants, willows and cottonwoods, are found. It closely resembles the Pipevine Swallowtail -- Battus philenor. This is an example of mimicry because the swallowtail is noxious for birds to eat and so the similar-looking Red Spotted Purple is left alone by the birds as well.
The caterpillar uses yet another trick to avoid being eaten. It looks like some sort of objectionable waste material - bird feces perhaps -- a disguise.
