(DRAFT) - Taxonomy
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
TAXONOMY
NAME - BUTTERFLY, BLUE, PALOS VERDES
OTHER COMMON NAMES - BUTTERFLY, BLUE and PALOS VERDES
ELEMENT CODE -
CATEGORY - Terrestrial Insects
PHYLUM AND SUBPHYLUM - ARTHROPODA,
CLASS AND SUBCLASS - INSECTA,
ORDER AND SUBORDER - LEPIDOPTERA,
FAMILY AND SUBFAMILY - LYCAENIDAE,
GENUS AND SUBGENUS - GLAUCOPSYCHE,
SPECIES AND SSP - LYGDAMUS, PALOSVERDESENSIS
SCIENTIFIC NAME - GLAUCOPSYCHE LYGDAMUS PALOSVERDESENSIS
AUTHORITY -
TAXONOMY REFERENCES -
COMMENTS ON TAXONOMY -
Palos Verdes Blue Butterfly
Glaucopsyche lygdamus palosverdesensis Perkins and Emmel, 1977
KINGDOM: Animal GROUP: Insect
PHYLUM: Arthropoda CLASS: Insecta
ORDER: Lepidoptera FAMILY: Lycaenidae
Morphological Description:
The Palos Verdes blue butterfly is a small blue lycaenid
butterfly (wingspan 25-30 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 (01).
Nomenclature:
Glaucopsyche lygdamus palosverdesensis Perkins and Emmel, 1977,
is one of 11 currently recognized subspecies of the species
Glaucopsyche lygdamus, which is widely distributed throughout North
America (02). No synonyms are known. Morphologically, the Palos
Verdes blue butterfly can be distinguished from other subspecies of G.
Taxonomy - 1 (DRAFT) - Taxonomy
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
lygdamus by its wing colors and spot (i.e., maculation) pattern.
Also, its foodplant is Astragalus trichopodus var. lonchus
(Leguminosae), whereas other nearby subspecies feed on Lupinus or
Lotus.
Type Specimens:
The holotype and allotype are deposited in the U.S. National
Museum of Natural History at the Smithsonian Institution in
Washington, D.C. Paratypes are in collections at the Allyn Museum of
Entomology, American Museum of Natural History, California Academy of
Sciences, Los Angeles County Museum of Natural History, and the Allan
Hancock Foundation at the University of California (01).
Descriptions and Photos:
Photos and descriptions are in the Perkins and Emmel article
dated 1977 (01). Descriptions of the Palos Verdes blue butterfly are
in the Recovery Plan (03) and the species' management plan (04).
Photos and descriptions of other subspecies of Glaucopsyche lygdamus
can be found in "The butterflies of North America" (02).
Taxonomy - 2 (DRAFT) - Status
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
STATUS
Coded Status
E: Federal Endangered
Game (Consumptive Recreational)
Non-consumptive recreational
COMMENTS ON STATUS -
U.S. STATUSES AND LAWS:
The Palos Verdes blue butterfly is listed as Endangered pursuant
to the Endangered Species Act of 1973, as amended (50 CFR 17.11). The
species may be extinct, but may still occur in Los Angeles County, CA.
However, it is protected wherever found. Critical Habitat has been
designated in Los Angeles, Co. (50 CFR 17.95 (i)) in Agua Amarga
Canyon in the southeast corner of Palos Verdes Estates; and part of
Frank Hesse Park, and the "switchback" area of Palos Verdes Drive,
Palos Verdes Estates.
RESPONSIBLE FEDERAL AGENCIES: The U.S. Fish and Wildlife
Service is responsible for the management/recovery, listing
and law enforcement protection of this species. The Department
of Defense is responsible for cooperation in the management
and protection of this butterfly.
STATE STATUSES AND LAWS:
Insects are not covered by California law.
INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS:
None.
ECONOMIC STATUSES:
The Palos Verdes blue butterfly is valued as a rare species by
butterfly enthusiasts and at times may have been collected illegally
for private butterfly collections.
78/07/03:43 FR 28938/28945 - Proposed rule, listing as Endangered
80/03/26:45 FR 19860/19861 - Proposed rule, designation of Crit. Hab.
80/07/02:45 FR 44939/44942 - Final rule, listed as Endangered
85/07/22:50 FR 29901/29909 - Five year review
Status - 1 HABITAT ASSOCIATIONS
HABITAT - TERRESTRIAL
TERRESTRIAL
LAND USE -
Residential
Transportation, communications, and Util
Shrub and Brush Rangeland
COMMENTS ON HABITAT ASSOCIATIONS -
The Palos Verdes blue butterfly is found in coastal sage scrub
habitat, where its larval foodplant, Astragalus trichopodus var.
lonchus (locoweed) grows. Coastal sage scrub vegetation is
characterized by semi-shrubs with a mosaic of various annual and
perennial herbaceous species interspersed in open areas. The species
is excludively peninsular, restricted to the cool, fog-shrouded,
seaward side of the Palos Verdes hills, Los Angeles County, CA. The
species is found on well drained clay or gravelly, sometimes rocky,
slopes of the coastal areas of the peninsula. Annual precipitation
averages 15 inches occurring in the winter months. Average
temperatures are about 54 degrees F in January and 70 degrees F in
July.
On the Palos Verdes Peninsula, common plant species in this
habitat include Artemisia californica (coastal sagebrush), Encelia
californica, Rhus integrifolia (lemonade berry), Lycium californicum
(boxthorn), Opuntia prolifera (cholla) and Eriogonum fasiculatum
(California buckwheat) (03,04).
Specific physical and environmental parameters required by Palos
Verdes blue butterfly are unknown at this time. The butterfly has
been found on the fog-shrouded marine terraces, hills, and canyons, on
the seaward side of the Palos Verdes Hills (01,04). Population
locations have been in fields near roads and intersections,
residential areas, canyons, roadcuts, rocky ridges, and in parks.
Refer to N-OCCURRENCE for specific site locations.
Habitat Associations - 1 (DRAFT) - Food Habits
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
FOOD HABITS
TROPHIC LEVEL -
HERBIVORE
LIFESTAGE FOOD FOOD PART
General Forb Flowers/Fruit/Seed
Food Habits - 1 (DRAFT) - Environment Associations
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Human Association: Public residential parks
Environment Associations - 1 (DRAFT) - Life History
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
LIFE HISTORY
FOOD HABITS:
Larvae of Palos Verdes blue butterfly feed only on the developing
flowers and seed pods of Astragalus trichopodus var. lonchus
(locoweed). Nectar resource plants of adults are unknown (01,03,04).
HOME RANGE/TERRITORY:
Unknown.
PERIODICITY:
Adults are diurnal and fly from early February until the end of
March (01,03,04).
MIGRATION PATTERNS:
Probably non-migratory, based on what is known about related
subspecies and species.
COVER/SHELTER REQUIREMENTS:
This butterfly occurs in coastal sage scrub habitat with
Astragalus trichopodus var. lonchus (locoweed, its larval food
plant). No information is available on minimum area of cover or other
requirements.
REPRODUCTIVE SITE REQUIREMENTS:
Oviposition occurs throughout the February to March flight
season. Eggs are laid on flower buds and leaves of Astragalus
trichopodus var. lonchus (05).
REPRODUCTIVE CHARACTERISTICS:
There is one generation per year (03,04). Adults are seldom
numerous, therefore, some specialized mate-locating behavior must be
employed. Although "hilltopping" (meeting mates at hilltops) would be
a logical mechanism due to terrain, proximity to the foodplant may be
a key to mate location since adults are always found in association
with the larval foodplant (05). Other characteristics are unknown.
PARENTAL CARE:
None.
POPULATION BIOLOGY:
Limiting factors are: 1) loss and alteration of habitat (via
weed abatement, fire preventative roto-tilling, construction
activities, and encroachment by exotic plants and 2) declining numbers
of the larval foodplant. No information is available on other
factors.
During 1984 and 1985, extensive searches of the Palos Verdes
Peninsula (Los Angeles County, CA) have failed to locate any eggs,
larvae, pupae, or adults of the Palos Verdes blue butterfly. The last
specimens were seen in 1983 (03). In 1985, Astragalus was observed
growing at only 10 of the 18 historic sites, but at seven of these
sites the numbers of surviving Astragalus plants was seven or fewer
(03). Due to the low biomass of Astragalus, it is unlikely that many
Life History - 1 (DRAFT) - Life History
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
butterflies could survive at these sites.
SPECIES INTERRELATIONSHIPS:
The Palos Verdes blue butterfly has a host-parasite relationship
with its sole larval foodplant Astragalus trichopodus var. lonchus.
This particular variety of the food plant does not have a common name,
however many Astragalus species are referred to as milk-vetch,
locoweeds, or rattleweeds. Some instars in the life cycle of this
butterfly may be tended by ants (but this has not been observed).
Ants tending other races of G. lygdamus protect larvae from
parasitoids. Interspecific competition from other lycaenid
butterflies for the larval foodplant, Astragalus, may occur. Everes
amyntula and Strymon melinus, other larval seed predators of
Astragalus, were more abundant at two colonies of G. l.
palosverdiensis. These larvae are cannibalistic, thus only one larvae
develops in a seed pod. This interspecific competition manifested as
cannabilism may be a limiting factor (03).
OTHER LIFE HISTORY DESCRIPTORS:
Larvae emerge in about 7 to 10 days, feed on the sepals and
gynoecia and eventually bore into the seed pods where they complete
development foraging on seeds and dermal tissue of the pods. There
are at least 4 larval instars, possibly five. In April, mature larvae
crawl down to the plant base and pupate in the duff (05).
Life History - 2 (DRAFT) - Management Practices
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Controlling/Restricting Off-Road Vehicles
Beneficial Restricting/regulating human disturbance of populations
Beneficial Maintaining undisturbed/undeveloped areas
Beneficial Land Acquisition
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Controlling/Restricting Pesticide Use
Beneficial Controlling/Restricting Herbicide Use
Beneficial Suppressing wildfire
Beneficial Reforestation
Beneficial Controlling/Removing Nonnative Vegetation
Beneficial Stocking captive-reared wild-strain animals
Beneficial Transplanting wild animals
Beneficial Restricting Poaching
Adverse Off Road Vehicles
Existing Off Road Vehicles
Adverse Inherent Reproductive Characteristics
Existing Inherent Reproductive Characteristics
Adverse Low Gene Pool
Existing Low Gene Pool
Adverse Rural Residential/Industrial Areas
Existing Rural Residential/Industrial Areas
Adverse Soil compaction by heavy equipment in mine areas
Existing Soil compaction by heavy equipment in mine areas
Adverse Competition
Existing Competition
Adverse Exotic/Feral/Introducted Species
Existing Exotic/Feral/Introducted Species
Adverse Grazing
Existing Grazing
Adverse
Existing
Adverse Vegetation Composition Changes
Existing Vegetation Composition Changes
Adverse Suppressing wildfire
Existing Suppressing wildfire
COMMENTS ON MANAGEMENT PRACTICES -
Due to its limited geographic range, the Palos Verdes blue
butterfly is extremely vulnerable to loss and alteration of its
habitat, coastal sage scrub. In recent years, residential and
commercial development and associated roads on the Palos Verdes
Peninsula has accelerated, and the loss of habitat has been
significant (03,04). Local fire prevention practices, whereby vacant
land is disked or roto-tilled prior to each year's fire season, have
also reduced the amount of available habitat (03,04). Weeds and
annual grasses displace native vegetation in areas that are disked
(03,04). Agriculture (row crops) and use of hillsides for grazing of
domestic animals, also affected habitat for Palos Verdes blue
Management Practices - 1 (DRAFT) - Management Practices
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
butterfly (03,04). Off-road vehicles have damaged habitat in a few
areas (03,04).
Several areas of habitat or potential habitat are zoned
residential, open-space recreational, or open-space hazard (because of
steep terrain and potential landslides) (03).
Many remaining areas where the butterfly may occur or its larval
foodplant occur are privately owned and zoned for residential
development (04). Thus urbanization continues to threaten the
existence of the butterfly. Some progress has been made to limit
disking for fire control in a few areas, but these efforts should be
expanded to other known sites. Until all known localities are
protected, fire control practices will continue to be a threat to the
survival of the Palos Verdes blue butterfly and its larval foodplant,
Astragalus (04).
The butterfly may be extinct, and if not it probably exists in
very low numbers. Due to the small population size, low density, and
patchiness of its larval food plant there may not be sufficient
genetic stock to assure survival. Its reliance on a single larval
food plant for reproduction further exacerbates the problem.
Interspecific competition with other lycaenid butterflies for
Astragalus (e.g., Everes amyntula, and Strymon melinus) and the
canabalistic nature of the larvae (only 1 larvae develops per seed
pod) may be limiting factors (03).
APPROVED PLAN:
U.S. Fish and Wildlife Service. 1984. Palos Verdes Blue Butterfly
Recovery Plan. U.S. Fish and Wildlife Service, Portland, OR. 46 pp.
[Note: When the Recovery Plan was developed there were seven
extant populations of the Palos Verdes blue butterfly. Since that
time this species has not been observed at any of its former
locations. However, it is possible this butterfly may yet occur at
some location(s) where its food plant is still in existence. See
field N-OCCURRENCE.]
The primary objective of the Palos Verdes Blue Butterfly Recovery
Plan is to protect and enhance the seven known populations. The
population and habitat criteria necessary to reclassify or delist the
taxon has not been quantified.
In order to accomplish the primary objective, the following
activities need to be accomplished:
1. Preserve, protect the habitats from further degradation and
development, and manage the larval and adult habitat at seven
identified sites and additional unsurveyed sites; habitat
protection can be achieved through agreements and by controlling
human activities (including fire control measures, use of
toxicants such as herbicides, pesticides, etc., and controlling
off-road vehicle activities).
2. Enhance butterfly populations by removing exotic plants from the
habitats, propagating and by transplanting Astragalus and other
coastal sage scrub plants.
3. Conduct research to determine: techniques for propagating larval
Management Practices - 2 (DRAFT) - Management Practices
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
foodplants; techniques to make habitat improvements; the
butterfly's autecology; and the bionomic autecology of Astragalus
trichopodus leucopsis.
4. Incorporate research findings into long-term management plans.
5. Reestablish habitat and butterflies at historic sites using stock
from existing colonies or captive propagated colonies; develop
management plans for restored sites; and protect these sites
through easements, agreements, leases, and/or land acquisition.
6. Monitor species habitat and management.
7. Determine number and size of colonies to permit declassification
to Threatened and delisted status.
8. Implement public information and education program; and
9. Enforce laws and regulation to protect the butterfly (e.g., from
unlawful take).
Management Practices - 3 (DRAFT) - References
Species BUTTERFLY, BLUE, PALOS VERDES
Species Id ESIS501007
Date 13 MAR 96
References
***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE *****
01 Perkins, E.M. and J.F. Emmel. 1977. A new subspecies of
Glaucopsyche lygdamus from California. Proc. Entomol. Soc. Wash.
79:468-471.
02 Howe, W. 1975. The Butterflies of North America. Doubleday, New
York.
03 U.S. Fish and Wildlife Service. 1984. Palos Verdes Blue Butterfly
Recovery Plan. U.S. Fish and Wildlife Service, Portland, OR.
46 pp.
04 Arnold, R.A. 1985. Palos Verde blue butterfly management plan.
U.S. Fish and Wildlife Service, Portland, OR. (in press)
05 Arnold, R.A. 1981. Distribution, life history, and status of
three California Lepidoptera proposed as endangered or threatened
species. Final Report, California Dept. of Fish and Game,
Sacramento, CA.
***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY *****
01 Perkins, E.M. and J.F. Emmel. 1977. A new subspecies of
Glaucopsyche lygdamus from California. Proc. Entomol. Soc. Wash.
79:468-471.
02 U.S. Fish and Wildlife Service. 1984. Palos Verdes Blue Butterfly
Recovery Plan. U.S. Fish and Wildlife Service, Portland, OR.
46 pp.
03 Arnold, R.A. 1985. Palos Verde blue butterfly management plan.
U.S. Fish and Wildlife Service, Portland, OR. (in press)
References - 1