Skippers Butterflies and Moths: Lepidoptera

Physical characteristics: Adult wingspan is 0.64 to 0.8 inches (16 to 20 millimeters) across. The upper side of the forewing is bright blue with large black spots. The underside of the forewing is grayish with large black spots and a bluish or greenish area near the base. The head of the larva is small and hidden. The legs are also hidden, and the body is covered with short hairs.

Geographic range: This species is found from western Europe to southern Siberia, Mongolia, and China.

Habitat: Large blues are found in dry, rugged, open grasslands where their host ants, Myrmica sabuleti, live. In the north, the ants prefer warm, south-facing slopes covered in short grass.

Diet: Younger larvae eat pollen and seeds of wild thyme and oregano, while the older caterpillars prefer ant eggs and larvae.

Behavior and reproduction: Females lay their eggs singly on flowers of thyme or oregano. Caterpillars feed on plants for about three Large blues are found in dry, rugged, open grasslands where their host ants, Myrmica sabuleti, live. (Illustration by Michelle Meneghini. Reproduced by permission.) weeks and then drop to the ground. From special glands they produce fluids that are attractive to ants. The ants pick up the caterpillars and carry them back to their nests. There the caterpillars prey on ant eggs and larvae. Pupation takes place in the nest. Adults emerge the following summer and live for about three or four weeks. They are active from June through August.

Large blues and people: Scientists study their relationships with ants to understand how different kinds of animals come to depend on each other. These studies provide useful information for the conservation of other species of blues whose caterpillars also depend on ants for their development.

Conservation status: This species is listed by the World Conservation Union (IUCN) as Near Threatened, or likely to qualify for a threatened category in the near future. Their populations have declined or disappeared in northern Europe. They have been reestablished in England and are still common in Siberia and the Far East. Their populations are threatened by the expansion of agricultural areas. ∎