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silvery blue
silvery blue (Glaucopsyche lygdamus) [female dorsal] [male dorsal]
Illinois Status: rare stray
Photo © Michael Jeffords/Susan Post
Features and Behaviors
FEATURES
The silvery blue is a small, hairy, grey-bodied butterfly with silvery blue wings with black and white margins (edges of the wing). The undersides of the wings are grey with black spots. The caterpillars vary in color, from green to purplish with a dark dorsal stripe and white dashes.
BEHAVIORS
There is one generation of these butterflies each year that can be seen flying from mid-April to late May in Illinois. Pupae overwinter in a chrysalis attached to the debris near host plants. The caterpillars feed on flowers and develop pods of plants in the family Fabaceae (peas) while adults are fond of the nectar found in composites (sunflowers). In a strange and fascinating symbiotic relationship, the sugary secretions of the silvery blue caterpillars attract ants, whose presence wards off small and large parasitoids. Females will even deposit their eggs where ants are present particularly in lupine.
Illinois Range
Taxonomy
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Lycaenidae
Habitats
The silvery blue is usually found in open areas within woodlands, often in regions with rocky or sandy soils.
