A western butterfly, it ranges from southern British Columbia and Alberta south through the western third of the U.S. It occurs through much of Idaho. Typically, it is an uncommon butterfly.
This species occurs in meadows, grassy fields, woodlands, and in coastal dunes and lowlands.
Caterpillars eat the flowers and fruits of legumes such as milk vetches (Astragalus
spp.) and lupines (Lupinus spp.).
Adult: Butterflies drink flower nectar.
The caterpillar is equipped with a honey gland, also known as a dorsal nectary organ, which emits a sugary solution agreeable to ants. The ants feed on the solution and in turn protect the caterpillar from predators. Also for protection, the caterpillar bears a pair of everscible tubercles or tentacles on the eighth segment. These tubercles are usually housed within the body, but when the caterpillar feels threatened by the approach of a potential predator, they can be pushed out to release a chemical which mimics an ant alarm pheromone. This scent causes the ants to become frenzied and aggressive, and the potential predator takes leave or is eaten by the ants. There is one generation of caterpillars each growing season. Each caterpillar undergoes four stages of growth, called instars. Pupae overwinter in a physiological state called diapause. Butterflies typically fly from March to early July.
Males actively patrol in search of females. Females lay eggs singly on host plants, primarily on flower buds.
|Idaho Status:||Unprotected nongame species.|
|Global Rank:||G5; most populations are widespread, abundant, and secure. Certain populations in California, however, may be in jeopardy.|
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