Adult red-spotted purples are thought to mimic pipevine swallowtails, and they can be difficult to separate from our various dark swallowtails if seen in flight at a distance.
Key identifiers:
- No "swallowtail" hindwing tails
- Seen from above, there are black lines near the hindwing margin
- Seen from below, there are red-orange spots on the wings. None of our swallowtails have red-orange spots near the body, seen from below.
The larvae mimic bird droppings. They are humped at the thorax and covered with numerous tubercles, with one longer pair on the thorax. The body color is mottled shades of brown, brownish yellow, white, and green.
Wingspan: 2¼–3½ inches.
Statewide.
Habitat and Conservation
Found in and near woods, parks, and suburban neighborhoods.
Adults frequently sit on trees and shrubs, slowly opening and closing their wings.
Adults are often seen at mud puddles and damp places along creek beds, where they take moisture from the damp ground.
Food
The caterpillars feed on a the foliage of a wide variety of deciduous trees and shrubs, including willows, wild cherry, apple, and crab apple.
The adults visit flowers, but they prefer to absorb moisture and nutrients from puddles, damp ground, decaying fruit, and animal droppings.
Status
Common breeding resident.
Life Cycle
Adults fly from May into October.
Partially grown caterpillars hibernate through winter sheltered in a rolled leaf that is spun into a tube and secured to the twig with silk. During hibernation, the caterpillar’s breathing and metabolic rate slow; its blood thickens, and the percentage of water in the body drops from 80 percent to 55 percent to prevent freezing damage.
Human Connections
Although the common name is a bit "off" (the spots are really orange, not red, and blue is more prominent than the subtle violet hues) the red-spotted purple is a stunning sight, evoking awe and appreciation.
Ecosystem Connections
Red-spotted purples are one of several blackish butterflies that gain protection from some predators through their resemblance to pipevine swallowtails. As caterpillars, the latter species eats pipevines, accumulating bitter toxic chemicals in their bodies. This makes pipevine swallowtails unpalatable to birds. Birds remember the large, black-and-blue butterflies and avoid any that share that look.
The larvae also use coloration to avoid being eaten — they resemble unappetizing bird droppings!
Taxonomy: If they're not swallowtails, what are they? Red-spotted purples are in the family Nymphalidae (nim-FAL-uh-dee), the "brushfooted butterflies." This is a large, diverse family:
- This family includes the monarch, viceroy, fritillaries, painted ladies, checkerspots, anglewings, mourning cloak, buckeye, crescents, emperors, satyrs, and more.
- All the butterflies in this family have their first pair of legs reduced and bristly (brushlike), and they walk using only the second and third pairs of legs (so they appear to be four-legged).
- In Missouri, the red-spotted purple's closest relative is the viceroy, which is in the same genus (Limenitis).
Our "red-spotted purple" form of this species used to be considered subspecies astyanax, separate from the other forms of this widespread North American butterfly.
- Elsewhere on the continent, at least two other forms (called "white admirals") are a lot like our butterfly, but they have the addition of a broad white band running across the middle of all the wings, both above and below. Look for white admirals in Canada, Alaska, New England, and the Great Lakes region.
- These different races interbreed in areas where their populations overlap, and their offspring often show a blend of characteristics.
- That they can interbreed indicates they should be considered only regional forms, or races, of a single species.
