The Swallowtail Butterflies

Al Lowe
Contributor

This group of butterflies has some of the largest ones in the world, and, in a great many cases, some of the prettiest. They are large and brightly coloured, and most of the typical North American ones have ‘tails’ on the bird wings.
I am sure that just about everyone has seen the Tiger Swallowtail. It is really easy to spot. It is mostly bright yellow, with black stripes on its forewings, and large black borders on both wings. These borders have yellow spots in them. Wingspan is over five inches, and the ‘tail’ is quite prominent. When this insect is sitting with its wings over its back, you can see both orange and blue spots along its bird wings.
The Tiger Swallowtail is one of the most common big butterflies of eastern North America. It should be really easy to recognize. Well, maybe not always. There are a number of species of Swallowtails which have quite similar patterns of yellow and black. The Western Tiger Swallowtail is quite a bit smaller, and it doesn’t come anywhere near eastern Canada at all. In the west, there is the Pale Swallowtail which, instead of yellow, has cream colour on its wings. And there are lots of others.
There are all kinds of Swallowtails, and they are pretty much all over the continent. But they need warm weather to survive, so there are more in warmer climates than where we live. Although there are over 600 species in the world, there are only about 30 in all of North America.
And there are dark versions of the Swallowtail as well. These are really dark. Their forewings are just about all black, with blue and tiny yellow spots along the edges. Hind wings are mostly dark blue, with quite prominent orange spots and little white crescent shaped ones, too.
Some of these butterflies restrict themselves to particular locations. The Short-tailed Swallowtail is also called the maritime one. It lives in the eastern provinces and eastern Quebec. The Oregon Swallowtail lives only in the Pacific northwest. The Desert Swallowtail comes in three different colour arrangements and lives in the dry areas of the southwestern states. Then there is the ‘Orange Dog’, the Ruby-spotted Swallowtail, the Two-tailed Tiger, and a couple of Zebra Swallowtails. These are striped, and you can guess what colours they are.
In other parts of the world, there are some really different ones. Australia has the largest butterfly in the world, the brilliant Birdwing. One tropical group, called Kites, have the longest tail of all (they are a form of Zebra Swallowtail).
The eggs of most Swallowtails are nearly round, and the caterpillars are usually smooth. A lot of the caterpillars have very prominent eyespots, which are thought to warn predators off, by just looking as though they are much bigger than they really are.
And a lot of Swallowtail caterpillars have an odd organ just behind the head. This has a foul smell, and can be turned inside out. Again to warn predators away. And some consume certain parts of plants which makes them taste terrible. Once a bird eats one of these, he is not likely to go for another one.
The chysalis of Swallowtails usually looks like a green or brown forgotten bit of wood, with a sort of angled, pointy shape. It is usually fastened to a plant stem by a silk belt around the middle.
So these Swallowtails are some of our largest, prominently coloured butterflies. I am sure that just about everyone has seen the yellow ones hanging around the lilacs in the early part of spring. Dark and blue, yellow and black, black and white - they form a really nice part of our early summer picture.