Northern Blue
Plebejus idas (Linnaeus, 1761)
Family: Lycaenidae
Subfamily: Polyommatinae
Identification: Geographically variable. Upperside of male iridescent blue, female brown with orange submarginal spots. Below, hindwing has a thin black line along outer margin which is broken into small dots at vein ends. Can be positively identified only by dissection of male genitalia and by locality.
Wing Span: 7/8 - 1 1/2 inches (2.2 - 3.8 cm).
Life History: Males patrol near host plants for females. Eggs are laid singly on stems of host plant or in debris beneath it. Second-stage caterpillars overwinter.
Flight: One brood from July-August.
Caterpillar Hosts: Plants of the heath family (Ericaceae) in the east; legumes of the pea family (Fabaceae) in the west.
Adult Food: Nectar from flowers including yarrow; dogbane; orange hawkweed; and white, alsike, and hop clover.
Habitat: Openings in mixed evergreen forests, bogs, wet meadows, seeps.
Range: Holarctic. Nova Scotia west through the Great Lakes area and southern Canada; north to Alaska; south to central California, southern Idaho, and southwest Colorado.
Conservation: Subspecies lotis is probably naturally rare with low population densities; it is found currently in only 1 out of 7 of its historic sites. Successional changes in vegetation due to human disturbance choked out the host plant Lotus formosissimus. Subspecies lotis has The Nature Conservancy rank of T1 - Critically imperiled because of extreme rarity (5 or fewer occurrences, or very few remaining individuals), or because of some factor of its biology making it especially vulnerable to extinction. (Critically endangered throughout its range). The species as a whole has The Nature Conservancy Global Rank of G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
NCGR:
Management Needs: The U. S. Fish and Wildlife Service recovery plan for the Lotis Blue cites the need for basic biological and ecological information about this butterfly. Three steps to recovery are listed: 1) protect remaining habitat and butterflies at the only known population site, 2) establish 3 new populations at different sites, and 3) determine the extent of the population and the size of secure habitats needed.
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Verified Sightings
Displaying 145 - 168 of 221 verified sightings
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Observation date: unknown
Submitted by: legacy.reporter
Region: Blaine County, Idaho, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Douglas County, Nevada, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Keweenaw County, Michigan, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Lane County, Oregon, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Lake County, Minnesota, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Jackson County, Oregon, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Alaska, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Sanders County, Montana, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: San Juan County, Colorado, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Deer Lodge County, Montana, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Lemhi County, Idaho, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Sweet Grass County, Montana, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Park County, Wyoming, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Stevens County, Washington, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Florence County, Wisconsin, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Clark County, Idaho, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Big Horn County, Montana, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Washington County, Idaho, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Marion County, Oregon, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Isle Royale County, Michigan, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Umatilla County, Oregon, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Lincoln County, Montana, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Harney County, Oregon, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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Observation date: unknown
Submitted by: legacy.reporter
Region: Chaffee County, Colorado, United States
Verified by: legacy.verifier
Verified date: Dec 31, 2004
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