EARTH LADY: Giant Swallowtail doesn’t require rain forest, just host plants

The Giant Swallowtail is the largest butterfly in North America. (Margaret Gratz)

The Giant Swallowtail is the largest butterfly in North America. (Margaret Gratz)

There is nothing quite so dramatic or exciting as a Giant Swallowtail butterfly fluttering about the garden, and after a tornado, such a beautiful butterfly is symbolic of hope and renewal. With its languid, yet rhythmic, flight pattern, it methodically visits flower after flower. Unlike so many butterflies, the Giant Swallowtail is not skittish and seems to enjoy leisurely gliding about on air currents.

The Giant Swallowtail, the largest butterfly in North America, can have a wingspan of up to 6 inches. The wings are blackish-brown with a double row of distinctive yellow markings. These yellow dots seem to form two large Isosceles triangles. At the tip of each spoon-shaped swallowtail there is a yellow dot that looks as if an artist took a paintbrush and delicately daubed a bit of yellow paint on each swallowtail. There is a red and blue dot on each hindwing.

When the wings are folded they are pale yellow with blue, black and red markings. The folded wings remind the Earth Lady of a pane from a delicate Tiffany stained glass window. The body of this butterfly is also pale yellow.

The caterpillar of the handsome butterfly can only be described as ugly. Citrus growers who consider the larvae of the Giant Swallowtail to be pests derisively call them “Orange Dogs.” The caterpillar is brown with mottled, dirty white markings. It has two fearsome looking osmeteria or horns that protrude from its head when it is threatened. When the caterpillar is young it looks exactly like a bird dropping, which discourages hungry predators, and as it gets older, the caterpillar looks like a menacing little snake, which also tends to discourage predators.

The host plants for the Giant Swallowtail are primarily plants in the Citrus Family. Host plants other than orange trees and lemon trees include common rue, prickly ash, hop tree and Hercules club. The Earth Lady is not real sure which host plant the Giant Swallowtail finds in her neighborhood, since her garden is too far north for citrus trees. Perhaps it finds Hercules Club trees growing down by the creek bank.

Giant Swallowtail butterflies can be found in glades, open woods and near streams, and they readily seek nectar from a variety of garden flowers and wildflowers. The Giant Swallowtail butterfly is widespread throughout the United States. North of the orange groves this butterfly’s reputation greatly improves and is not considered to be a pest. The Earth Lady will be adding Common Rue or Herb of Grace to her garden in order to attract more Giant Swallowtail butterflies.

Large, exotic butterflies are associated with the tropics, but the Giant Swallowtail does not require an Amazon forest. If host plants are in the area, a suburban garden with tempting nectar plants will suffice. When the Giant Swallowtail butterflies visit the garden, one can feel the allure of the tropics.

The Earth Lady by Margaret Gratz appears in the Daily Journal Home & Garden section once a month.