This butterfly is in the Order Lepidoptera, family Lycaenidae. The Eastern Tailed-Blue has a narrow tail on the hind wing. Males have iridescent blue coloring on the upper side of the wings. Summer generation females are uniformly brown, while spring females tend to be much smaller with a lot of blue at the base of their wings. The underside of the hind wing is pale grey with a black bar (line) and distinct black spots. There are also three large orange spots on the underside of the wing located near the base of the tail. The wingspan of these butterflies is between 7/8 and 1 1/8 inches. Eastern Tailed-Blues tend not to perch with open wings, but will warm themselves in the sun with their wings opened at 45 degree angles.
Males can be found patrolling near and around the host plant during daylight hours. The females lay their eggs on the flower buds of the host plant and caterpillars (larvae) feed on the buds, flowers, and seeds after hatching. The caterpillars hibernate throughout the winter and pupate the following spring. In northern areas, there are three main broods between April and November, while in the South there are numerous broods. Caterpillars feed on many plants in the pea family including yellow sweet clover (Melilotus officinalis), alfalfa (Medicago sativa); various species of vetch (Vicia), clover (Trifolium), wild pea (Lathyrusll), and bush clover (Lespedeza). Adult butterflies take nectar from white sweet clover, shepherd's needle, wild strawberry, winter cress, cinquefoils, asters, and other small flowered plants. They are generally found on flowers growing close to the ground.
These butterflies are found in open and sunny locations that are typically weedy. They have a wide distribution, and they can be found from Southeast Canada and the Eastern United States west to western North Dakota, central Colorado, and central Texas. They also are found from southeastern Arizona, western New Mexico, and west Texas south to Costa Rica.
Chris Moss & Leigh Thackston
Insect Biology and Diversity (ENT / BIOSC 301)
Fall 2004
