The distinctive yellow and black markings are unlike any other insect, making it easily identifiable. They are large, graceful insects that love open, sunny gardens with a good selection of flowers.
The tiger swallowtail, (Papilio glaucus) is one of our most beautiful butterflies and was named by Linnaeus in 1758. It has been a beloved subject in paintings and artwork for centuries and has been designated the state butterfly of Delaware, South Carolina and Georgia and has also been honored as the state insect of Virginia.
There's some interesting symbolism connected to butterflies as well. It is curious that in both the ancient worlds of North America and Europe, the butterfly is connected to the human soul. Many cultures believed that a visit from a butterfly was a visit from a deceased loved-one to make sure all was well with them. In Christian culture the three stages of the butterfly represent the human condition. The caterpillar represents the earth-bound life, while the pupa represents the tomb and death, while the butterfly itself is the soul, reborn in heaven. In early artwork of Mary and the Christ Child, butterflies represent their love of the human soul. The ancient Irish believed that white butterflies were the souls of dead children and it was against the law to kill one.
When gardens start to bloom, butterflies inevitably show up and the tiger swallowtails are arguably the showiest. So named because of the two long 'tails' on their hind wings that are similar to the long tail feathers of the barn swallow bird. These large butterflies are attracted to colorful flat-topped flowers like zinnias and also love nectar from blooming shrubs and trees. Females prefer cherry trees, magnolias, tulip trees, willows and ash as host plants for their young and the large green caterpillars are quite distinctive with the 'eyespots' that are designed to scare off predators.
Male tiger swallowtails are always the familiar yellow and black. They have a couple of small blue spots at the base of their wings. The females can vary in appearance and are usually larger than the males. Female tiger swallowtails can display the yellow/black combination with a wider band of blue at the base of their wings. They also have a dark form that looks nothing like the bright yellow and black combination. The dark form mimics the pipevine swallowtail, (Battus philenor) which is poisonous to predators. This form is more prevalent in the southern part of its range where the pipevine swallowtail is present. Observers can distinguish them apart by noticing that the tiger swallowtail has a dark band separating the blue on the hind wings and the blue on the pipevine swallowtail has a greenish cast.
In the southern part of its range, there can be up to three flights in a season, which pretty much guarantees tiger swallowtails in the garden all summer. In the northern part of its range, there are only two flights. Adult butterflies live for about a month. The western tiger swallowtail (Papilio rutulus) and the Canadian swallowtail (Papilio canadensis) are very similar species and although they generally range a bit smaller in size, it is possible for the 3 species to hybridize, so where the territories overlap crossbreeding and hybrids are possible.
Females lay their eggs on the host trees and the caterpillars hatch and begin to eat. They are never present in enough numbers to do lasting damage to the plants, so just leave them be. The caterpillars grow quickly and are generally mature and are ready to pupate in about 30 days. They have a distinctive appearance with two large 'eyespots' on the top of their heads giving them the appearance of a snake. This is a natural defensive mechanism designed to trick birds and other predators into avoiding them.
To attract the tiger swallowtail to your garden, make sure you have some sunny, open spaces and colorful flowers. They love zinnias and most any flower of the Asteraceae family. Buddlejas and wigelias are also favorite nectar plants. Host trees and shrubs nearby are also a plus. Remember that pesticides meant for chewing insects will kill the caterpillars as they eat the host plants, so if you want butterflies, learn to appreciate the chewed leaves. Any garden where you want to encourage butterflies and pollinators should have very limited use of pesticides, if at all. Give them a sunny damp spot on the ground so they can gather and sip minerals from the mud. This activity, called 'puddling' is something that male butterflies do to obtain salts and minerals necessary for breeding, so make sure there is a damp spot where they can congregate. It is a fantastic sight to see! These conditions are excellent for attracting tiger swallowtails and other butterflies to your garden.
Images are my own and from BugFiles.