Palos Verdes Blue Butterfly

Glaucopsyche lygdamus palosverdesensis

Overview

The Palos Verdes blue was listed as an endangered species in 1980, when the animal was known from only three locations on the Palos Verdes peninsula in California. By 1984, because of urban development and the construction of a ballfield at Hesse Park, the species was believed to have become extinct. In 1994, the butterfly was discovered at a site managed by the Department of Defense in south Los Angeles, renewing hopes for the survival of this species.

The Palos Verdes Peninsula, on the coast south of Los Angeles, is a shrinking patch of coastal scrub community that has been under increasing pressure of urban development. Other factors causing the decline of this community, and this butterfly's locoweed host plant in particular, include weed control, off-road vehicle use, non-native plant invaders, and fire suppression.

Description

The Palos Verdes blue butterfly is in the family Lycaenidae (gossamer wings). It is a small butterfly with a wingspan between 25 and 30 mm. In the male, dorsal wing surfaces are colored a brilliant silvery-blue and outlined by narrow black borders. Dorsal wing surfaces of the female are brownish-gray in color, with a blue irridescence. In both sexes, the ventral wing surfaces are chalky gray in color, with several round spots highlighted by white rings.

Life History

The Palos Verdes blue (Glaucopsyche lygdamus paloverdesensis) is dependent on two known host plants, locoweed (Astragalus trichopodus var. lonchus, also known as Santa Barbara milkvetch) and common deerweed (Lotus scoparius). It has a single adult flight period extending from late January through mid-April. Eggs are normally laid in the flower heads of either deerweed or locoweed, where the caterpillars will feed. When the larvae are mature, they crawl into the leaf litter at or near the base of the food plant to find a place to pupate. They remain as pupae through the summer and winter, emerging as adult butterflies early the following spring.

Distribution

The Palos Verdes blue is restricted to the cool, fog-shrouded seaward side of the Palos Verdes Hills. It is one of eleven subspecies of the silvery blue butterfly (Glaucopsyche lygdamus) whose historic range probably extended over much of the Palos Verdes peninsula, on the coast south of Los Angeles.

Conservation Status

A survey in 2000 found there was a drastic decline in the numbers of adults. The total was the lowest recorded for a season since counting was initiated in 1994.

Conservation Needs

The Defense Logistics Agency, with Rudi Mattoni from UCLA and The Urban Wildlands Group, and various partners within the local community are working to restore habitat for the one known butterfly population at a military fuel terminal located in an industrial area of the Palos Verdes Peninsula.

Working with landowners

Information unavailable at time of publication.

Education

Education sheets available at zoological facilities (e.g. zoos, aquariums, botanical gardens with butterflies, butterfly houses, natural history museums) or events at which BFCI partners participate are a valuable way to disseminate information about imperiled butterflies.

When schools and other youth organizations study biodiversity and species extinctions they typically use examples of charismatic megafauna (e.g. bald eagles) or exotic creatures from the tropics. However, vulnerable species found within the state or ecoregion in which students live provide an excellent opportunity to develop curricular materials with a direct link to the students' home region. In addition to classroom studies, students may be able to visit sites to see the butterflies, as well as talk to the scientists and land managers involved in the species' conservation.

Educational activities that school students and community members could do include:

studying butterfly (insect) life stages;
researching the special habitat needs of the Palos Verdes blue;
corresponding or meeting with the biologists managing current Palos Verdes blue sites;
visiting Palos Verdes blue sites during adult flight season;
visiting captive breeding programs;
assisting scientists with on-site habitat management;
propagating and growing host plants for planting at butterfly sites or use in captive breeding programs; and
writing letters to decision makers to ensure that the Palos Verdes blue receives adequate resources and protection.

Research

Insufficient information available at time of publication.

Captive Rearing

There is an active captive rearing program in place at this time. Presently, 600 pupae are incubating and plans are to produce 5,000 in 2004. Currently, there is an expressed need for an additional captive rearing facility. Contact Dr. Travis Longcore for more information.

Recovery Plan

Mitchell's Satyr Butterfly Recovery Plan, April 2, 1998.

The primary objective of the recovery program is to remove the Mitchell's satyr butterfly from the List of Endangered and Threatened Wildlife by: (1) achieving a well-distributed increase in numbers; and (2) providing for long-term habitat protection.

The butterfly can be reclassified from endangered to threatened: when 16 geographically distinct, viable populations or metapopulations are established or discovered range wide. These will include, at a minimum, 12 populations or metapopulations in southern Michigan, two in Indiana, one in Ohio, and one metapopulation in New Jersey. At least 50 percent of these sites will be protected and managed to maintain Mitchell's satyr habitat by federal or state agencies or by private conservation organizations. The butterfly can be delisted when nine additional, for a total of 25, geographically distinct, viable populations or metapopulations are established or discovered range wide and remain viable for five consecutive years following reclassification. A minimum of 15 sites must be protected and managed to maintain Mitchell's satyr habitat by state or federal agencies or by private conservation organizations before delisting will be considered.

Recovery Priorities

Actions needed for recovery:

Monitor existing populations and survey for additional populations of Mitchell's satyr. Include surveys for previously unknown populations of Mitchell's satyr, monitoring extant populations and determining precise distribution of Mitchell's satyr at known population sites.
Establish a research program to determine the ecological requirements and life history of Mitchell's satyr. Research needs include conducting cage studies of larval ecology, quantifying habitat requirements and use, studying response to habitat disturbance, determining minimum population viability, and conducting captive rearing / reintroduction studies.
Develop and implement protection strategies for Mitchell's satyr. This step includes identifying sites vulnerable to poaching and providing protection during the flight season, protecting essential habitats, providing and updating current site occurrence information at least yearly, developing and implementing habitat management plans on public land and promoting protection of occurrences on privately owned land through an outreach program.
Develop an outreach program to keep local communities informed of the butterfly's status. Increase public awareness about Mitchell's satyr butterflies and their habitat through the development of public outreach and education programming.
Develop and implement a strategy for reestablishing populations of Mitchell's satyr through its historic range. This will include management of habitat as well as establishment of a rearing facility to provide butterflies for introduction into the wild. This task will require the establishment of Mitchell's satyr breeding facilities and reestablishment of historic populations.

In order to accomplish the interim objectives and formulate primary objectives, the following recovery activities are listed in the plan:

Preserve and protect populations at all known, new, and reestablished sites.
Establish three new, self-sustaining viable populations on suitable secure habitats of at least two hectares.
Conduct ecological studies to develop management recommendations, determine larval and adult host plants, physiological requirements, demographics, and other biological/ecological studies, and to determine criteria for declassifying and delisting.
Develop and implement public information and education programs.
Enforce laws and regulations prohibiting illegal take and enforce land use plans and ordinances.

For more information

USFWS contact: Alison Anderson, Carlsbad Fish and Wildlife Office, 2730 Loker Avenue West, Carlsbad, CA 92008 Phone (760) 431-9440
Travis Longcore, The Urban Wildlands Group, P.O. Box 24020, Los Angeles, CA 90024-0020. longcore@urbanwildlands.org
Rudi Mattoni, UCLA. Phone (310) 825-3019, mattoni@ucla.edu

References and Resources

Arnold, R. A., 1987. Decline of the endangered Palos Verdes Blue Butterfly in California. Biological Conservation 40(3):203-217.
Lipman, A., T. Longcore, R. Mattoni, and Y. Zhang. 1999. Habitat Evaluation and Reintroduction Planning for the Endangered Palos Verdes Blue Butterfly. Report to California Fish and Game. Available at Urban Wildlands.
Longcore, T., R. Mattoni, A. Lipman, Z. Krenova and C. Rich. 2002. Year 2002 Captive Rearing of Palos Verdes Blue Butterfly at Defense Fuel Support Point, San Pedro. The Urban Wildlands Group Defense Agency Agreement # N68711-02-LT-00010. 17 pp. Available at Urban Wildlands.
U.C. Berkeley, Essig Museum of Entomology. California's Endangered Insects Palos Verdes blue page.
USFWS Palos Verdes blue butterfly page

back to species profiles

Classification

Federal Threatened Species (Federal Register 45: 44939-44942, July 2 1980)

State Status

No state designation beyond the federal classification.

Range

Critical Habitat

Designated in Federal Register 45 FR 44939 44942, July 2 1980.

Acknowledgement

This profile was prepared by the Xerces Society for the Butterfly Conservation Initiative.