Winter form (dry-season) Tailed Orange (Pyrisitia proterpia) butterflies have tail-like projections on their hindwings, while the summer form (monsoon or wet-season) butterflies like this one do not.
This Tailed Orange butterfly was taking shelter under a leaf from the first scattered drops of an afternoon thunderstorm near Tucson in early September. As soon as rain threatens, butterflies seem to almost magically disappear.
Tailed Orange butterflies have yellow ventral wing surfaces and orange dorsal wing surfaces that are mainly visible in flight. These butterflies can best be identified by their hindwing "tails", and if these are not present, they can be recognized by their squared-off, point-tipped forewings and by the slanted, almost cutoff appearance of the straight lower edge of their hindwings.
Adult Tailed Orange butterflies feed on flower nectar, while their caterpillars feed on plants in the Pea Family (Fabaceae).