Shasta Blue
Plebejus shasta (W.H. Edwards, 1862)
Family: Lycaenidae
Subfamily: Polyommatinae
Identification: Upperside of male lilac blue with a wide dark border; female darker, may have orange band at outer margin of hindwing. Both sexes with dark cell bars on fore- and hindwings. Underside of both sexes gray with black postmedian spots; other spots are dark gray. Hindwing outer margin with iridescent green spots capped by a light band.
Wing Span: 7/8 - 1 1/8 inches (2.2 - 3 cm).
Life History: Males fly just above the ground to search for females. Eggs are laid singly on leaves of host plants; caterpillars feed on leaves and flowers. Where found above timberline, these butterflies require 2 years to mature, spending their first winter as eggs and the second winter as mature caterpillars.
Flight: One brood from June-August.
Caterpillar Hosts: Various Astragalus, Lupinus, and Trifolium species of the pea family (Fabaceae).
Adult Food: Flower nectar.
Habitat: Cushion-plant communities in forest openings, sagebrush hills, high plains, prairies, and alpine fell-fields.
Range: High elevations from Washington east to North Dakota and Nebraska; south to central California and Colorado.
Conservation: Not usually of conservation concern.
NCGR: G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
Management Needs: Not reported.
Comments: NULL
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Verified Sightings
Displaying 1 - 24 of 325 verified sightings
Observation date: Jul 10, 2018
Submitted by: Cheri Phillips
Region: Larimer County, Colorado, United States
Verified by: mikefisher
Verified date: May 29, 2023
Observation date: Jul 04, 2018
Submitted by: Robb Hannawacker
Region: Cache County, Utah, United States
Verified by: RaisingButterfl...
Verified date: Dec 15, 2022
Observation date: Aug 21, 2022
Submitted by: MAKI
Region: Eureka County, Nevada, United States
Verified by: Ken Davenport
Verified date: Oct 13, 2022
Observation date: Sep 09, 2022
Submitted by: dchartier
Region: Summit County, Colorado, United States
Verified by: mikefisher
Verified date: Oct 02, 2022
Observation date: Jul 11, 2021
Submitted by: smasta
Region: Klamath County, Oregon, United States
Verified by: Ken Davenport
Verified date: Dec 31, 2021
Observation date: Jul 31, 2021
Submitted by: bjones7777
Region: Park County, Wyoming, United States
Verified by: J_Martineau
Verified date: Sep 07, 2021
Observation date: Jul 20, 2021
Submitted by: mstanek
Region: Mariposa County, California, United States
Verified by: Ken Davenport
Verified date: Jul 21, 2021
Observation date: Jul 11, 2014
Submitted by: chherrmann
Region: Clark County, Nevada, United States
Verified by: Ken Davenport
Verified date: Jun 14, 2021
Observation date: Jul 25, 2020
Submitted by: papilio1
Region: Washoe County, Nevada, United States
Verified by: Ken Davenport
Verified date: Jul 29, 2020
Observation date: Jun 25, 2019
Submitted by: J_Martineau
Region: Natrona County, Wyoming, United States
Verified by: J_Martineau
Verified date: Dec 04, 2019
Observation date: Jul 28, 2019
Submitted by: A_baldini
Region: Larimer County, Colorado, United States
Verified by: mikefisher
Verified date: Oct 13, 2019
Observation date: Sep 08, 2019
Submitted by: sfbaywildlife
Region: California, United States
Verified by: Ken Davenport
Verified date: Sep 21, 2019
Observation date: Aug 25, 2019
Submitted by: tirvine2020
Region: Teton County, Wyoming, United States
Verified by: J_Martineau
Verified date: Sep 04, 2019
Observation date: Jul 14, 2019
Submitted by: tomoclark
Region: Modoc County, California, United States
Verified by: Ken Davenport
Verified date: Jul 20, 2019
Observation date: Jun 26, 2019
Submitted by: ncrosbyrd
Region: Deschutes County, Oregon, United States
Verified by: Ken Davenport
Verified date: Jul 14, 2019
Observation date: Aug 23, 2008
Submitted by: hydapse
Region: Park County, Wyoming, United States
Verified by: J_Martineau
Verified date: Feb 07, 2019
Observation date: Aug 08, 2018
Submitted by: Robert Gorman
Region: Mono County, California, United States
Verified by: Ken Davenport
Verified date: Aug 20, 2018
Observation date: Jul 15, 2018
Submitted by: Lisahug
Region: White Pine County, Nevada, United States
Verified by: Ken Davenport
Verified date: Aug 03, 2018
Observation date: Jul 12, 2018
Submitted by: Robert Gorman
Region: Sierra County, California, United States
Verified by: Ken Davenport
Verified date: Jul 19, 2018
Observation date: Jul 14, 2018
Submitted by: Robert Gorman
Region: Mono County, California, United States
Verified by: Ken Davenport
Verified date: Jul 18, 2018
Observation date: Aug 06, 2016
Submitted by: coreyk
Region: Mono County, California, United States
Verified by: Ken Davenport
Verified date: Aug 12, 2016
Observation date: Aug 06, 2016
Submitted by: coreyk
Region: Mono County, California, United States
Verified by: Ken Davenport
Verified date: Aug 12, 2016
Observation date: Jul 03, 2013
Submitted by: MAKI
Region: Washoe County, Nevada, United States
Verified by: Ken Davenport
Verified date: Oct 06, 2013
Observation date: Jul 02, 2009
Submitted by: tjantscher
Region: Carbon County, Wyoming, United States
Verified by: kent
Verified date: Jan 10, 2013
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