Arizona Sister

About the Arizona Sister

A large, striking butterfly, blackish above with a broad white band crossing each wing and a bright orange patch near the tip of each forewing. Underneath the pattern turns to an intricate marbling of blue-gray, russet, and white - so different from the upperside that a settled individual with closed wings looks like another species entirely.

Sisters have a distinctive flight, alternating a few quick wingbeats with long flat glides on wings held out level, sailing through the dappled light under oaks. They perch with wings spread on sunlit leaves and are strongly territorial, launching out at anything passing and returning to the same leaf. They rarely visit flowers, preferring oozing sap, rotting fruit, and damp ground.

The caterpillars feed on oaks and are elaborately camouflaged, and the young larva builds a perch of leaf debris and frass to rest on, which conceals it against a leaf.

In Texas the Arizona Sister is a butterfly of the mountain canyons of the west - the Chisos, the Davis Mountains, the Guadalupes - wherever oaks grow at elevation. It is one of the characteristic insects of those sky islands, and in the Chisos on a warm afternoon they patrol the oak-lined trails at eye level.