The Eastern Tailed Blue, Cupido comyntas, is a common butterfly in Indiana summers. The Eastern Tailed blue feeds on a variety of legumes including clovers. The larvae often feed on the flowers and seeds of their host plant. Flowers and seeds typically contain more protein than the foliage.
The Eastern Tailed Blue has adapted to feed on many plants not native to North America. It has a wide geographic range and is found in many disturbed sites. Like many of the butterflies in the family Lycaenidae, the larvae may at times be tended and protected by ants.
Another species of butterfly in the family Lycaenidae is the Karner Blue. The Karner Blue is on the endangered species list. The Karner Blue feeds almost exclusively on lupine and is only found in a few small geographic areas including protected sites in Northern Indiana. The Eastern Tailed Blue is not endangered because it is adaptable to many host plants and a wide geographical area.
The adults of the Eastern Tailed Blue have similar size and color pattern to the Summer Azure. The “tails’ on the hind wings of the Eastern Tailed Blue can be damaged over time. However, Eastern Tailed Blues can be readily distinguished from the Summer Azure by the orange spot on its hind wing.