How to Identify Swallowtail Butterflies

Check flowering plants and trees to try to locate swallowtail caterpillars. Like the adult butterflies, they come in a variety of colors, but unlike other species, swallowtails have a fleshy forked organ behind their head called an osmeterium. When threatened, they use this to emit a foul smelling secretion for protection.

Search for Zebra Swallowtails on some of their favorite food sources which are blackberries, blueberries, lilacs and milkweed. They have bold black and white striped wings with some small red markings on their hind wings. The adults have a wingspan of three to four inches wide, and they have long black "tails" on their hind wings that resemble the tail of a swallow, hence the name.

Look for Tiger Swallowtails in woodland areas. They have a bright yellow and black striped pattern on their wings with the red markings similar to the Zebra Swallowtail. They also have the trademark long black tail on each of their wings, but their wingspan ranges from 4 to 6 inches making them one of the larger of the butterfly species.

Watch for the Black Swallowtail to appear in your vegetable garden. Their eggs are typically found on carrots, parsley and fennel. They are one of the smaller butterflies with a wingspan of only three inches, and the upper surface of the wings is solid black. On the hind wing, there will be a black spot centered in a big splash of orange. The males will have a yellow band while the female has a row of yellow dots near the edge of their wings followed by the long black swallow tail.

Visit the western United States to find the Anise Swallowtail found in mountain fields or along the roadside. The upper and lower sides of its wings are black, but the upper wing has a broad yellow stripe across it, giving the butterfly an overall yellow appearance. It has bright blue spots on the outside edge of the rear wing along with the trademark tails.