Family:Lycaenidae
Family
Description:
Alternate Common Names:Emerald-Studded Blue,
Silver-Studded Blue.
Note: The distinctions between this
species and the Lupine Blue, Plebejus [Icaricia] lupinus, are unclear
and debated by scientists.
Range:
A widespread species, it ranges from southern British Columbia east to southwestern
Saskatchewan, and south through the western half of the U.S. to Mexico. It occurs
throughout Idaho. Isolated populations
may occur in Minnesota and New Jersey.
Habitat:
It utilizes a wide variety of habitats, including fields, prairies, open woodlands, and deserts.
Diet:
Caterpillar:
Caterpillars feed on the leaves, flowers, and fruits of wild buckwheat (Eriogonum
spp.) and legumes such as trefoils (Lotus
spp.), milkvetches (Astragalus spp.), and lupines (Lupinus spp.).
Adult:
Butterflies drink flower nectar.
Ecology:
Caterpillars often can be found inside host plant pods. Each 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 can be several generations
of caterpillars each summer in most of the range, but only one in the north.
Each caterpillar undergoes four stages of growth, or instars. Young caterpillars
overwinter in a physiological state called diapause. Adults generally fly from February to october.
Butterflies may disperse to some degree, as the isolated populations in Minnesota
demonstrate. The New Jersey population was probably introduced. This is one
of the most common Blues in the west.
Reproduction:
Males actively patrol
in search of receptive females. Females lay light green eggs singly on the leaves
and flowers of host plants.
Conservation:
Idaho Status: | Unprotected nongame species. |
Global Rank: | G5; populations are widespread, abundant, and secure. |
Ferris, C. D. and F. M. Brown. (eds.) 1981. Butterflies of the Rocky Mountain States. Univ. of Oklahoma Press, Norman, Oklahoma, USA, 442 pp.
Opler, P. A., H. Pavulaan, and R. E. Stanford. 1995. Butterflies of North America. Jamestown, North Dakota, USA: Northern Prairie Wildlife Research Center Home Page. http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/bflyusa.htm (Version 05Nov98).
Opler, P. A. and A. B.Wright. 1999. A Field Guide to the Western Butterflies. Second Edition. Peterson Field Guide Series. Houghton Mifflin Company, New York, New York, USA, 540 pp.
Pyle, R. M. 1981. National Audubon Society Field Guide to North American Butterflies. Alfred A. Knopf, Inc., New York, New York, USA, 924 pp.
Scott, J. A. 1986. The Butterflies of North America. Stanford University Press, Stanford, California, USA, 583 pp.
Stanford, R. E. and P. A. Opler. 1993. Atlas of Western U.S.A. Butterflies (Including Adjacent Parts of Canada and Mexico). Published by authors, Denver, Colorado, USA, 275 pp.