This queen ain't no monarch but it's still butterfly royalty. The queen butterfly can be mistaken for the better known cousin monarch butterfly, and the resemblance is no accident.
Both the queen and the monarch are members of the same genus — Danaus — Danaus gilippus, in the case of the queen. Both use milkweeds as a host plant, as does a third member of the clan, the soldier, which looks so much like its cousin, it's sometimes called the tropical queen.
Females of the Danaus clan lay their eggs on the leaves, stems and flower buds of various milkweed species. The caterpillars munch on the plant and take in toxins — cardiac glycosides called cardenolides. These chemicals give Danaus butterflies, including the queen, their trademark dark-orange color. It also makes both the caterpillars and adults poisonous to any vertebrate predator, birds in particular, that might eat one.
Adults signal the presence of the toxin via their orange coloration. A bird that tries to dine on the queen, monarch or soldier (or a third, distant cousin called the viceroy) will associate the color of his meal with the resulting severe stomach ache and more than likely stay away from eating anything orange ever again. And he's not likely to feed it to his offspring.
The differences between the species are somewhat subtle but the easiest way to tell the species apart is this: monarchs (and viceroys, which closely resemble monarchs) have dark, heavy veins outlined in black on the upper side of their wings; the veins on queens are fine. Soldiers have darker veining than queens but lack the black outlines of the monarch and viceroy. Soldiers are a little darker overall than queens and have fewer white spots on the leading edge of the forewings.
Queens are found throughout much of the United States, particularly the Southeast, Central Plains and the Southwest. They'll range as far north as Massachusetts and Nebraska and as far west as California. Queens are also found south through Mexico, the Caribbean, Central America and South America to Argentina. Adults are active year round in warmer parts of their range, including Florida, but limited to midsummer up north.
Queens are large as butterflies go, with a wingspan that approaches 4 inches. They are orange, or chestnut brown, The edges of the forewings are black, with two rows of white spots. Back edges of the hindwings are solid black. Males and females are generally alike in size and appearance, but the guys have fairly large black spots on their hind wings. These are called androconia scent scales and disseminate pheromones that attract potential mates.
Females may mate up to 15 times a day. They'll lay eggs singly on a leaf or flower of a host plant. In warmer parts of their range, queens will produce as many as three generations during a year.
Adults dine on the nectar of various flowers, including Spanish needles and milkweeds, as shown in the photos. They like fields, roadsides and dunes.
Queens and its cousins are member of Nymphalidae, or the brush-foot family.