Papilio glaucus Linnaeus  
Family: Papilionidae
Eastern Tiger Swallowtail,  more...
Papilio glaucus image
Andrew Homiak  
EoL Summary: The tiger swallowtail, or eastern tiger swallowtail (Papilio glaucus) is a species of the papilionid butterfly family native to North America. It is large butterfly (wingspan 7.9 – 14 cms), and one of the most familiar butterflies in the eastern United States, where it is common in many different habitats. It flies from spring to fall, during which time it produces two to three broods. Adults feed on the nectar of many species of flowers. Males are yellow with four black "tiger stripes" on each fore wing. Females are dimorphic in coloration, and can be found in as either a yellow or black morph. The yellow morph is similar to the male, while the dark form, which has long been thought to mimic the poisonous pipevine (blue) swallowtail, (Battus philenor), is almost completely black. 

The eastern tiger swallowtail lays her green eggs singly on hostplants in many woody plant families, most commonly on Magnoliaceae and Rosaceae (for example, poplars, mountain ash, birch, cherry, tulip tree, ash, basswood, apple, maple, willow, magnolia, and occasionally sassafras). Young caterpillars (first three instars) are brown and white, with a coloration pattern that mimics bird droppings to help protect it from predators. In later instars, caterpillars are green with two black, yellow, and blue eyespots on the thorax, thought to deter birds. Caterpillars reach a length of 5.5 cm.