Arizona Bird Dropping Moth
Ponometia elegantula
Several of these moths were found at night visiting flowers of Larrea tridentata. Mohawk Mountains, Yuma Co., Arizona. 20 Feb. 2016. Length of the resting moth is about 7 mm.
Noctuidae -- Owlet Moth Family
During the day when it is resting on a leaf or other surface it strongly resembles a bird dropping. Apparently this works to confuse insectivorous birds as to its edibility. The food plant for the larva of this moth is not certainly known, but I strongly suspect a species of Ambrosia. A worth while study would be to find a larva on the host plant and rear it to the adult stage moth.