Palos Verdes blue

Last updated

Palos Verdes blue
PVBlue.jpg
Status TNC T1.svg
Critically Imperiled  (NatureServe) [1]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Lycaenidae
Genus: Glaucopsyche
Species:
Subspecies:
G. l. palosverdesensis
Trinomial name
Glaucopsyche lygdamus palosverdesensis
E. Perkins and J. Emmel, 1977

The Palos Verdes blue (Glaucopsyche lygdamus palosverdesensis) is a small endangered butterfly native to the Palos Verdes Peninsula in southwest Los Angeles County, California, United States. As its distribution has been proven to be limited to one single site it has one of the best claims to being the world's rarest butterfly.

Contents

Overview

The Palos Verdes blue (G. l. palosverdesensis) is a localized subspecies of the silvery blue ( G. lygdamus ), which ranges over much of North America. It was described in 1977, shortly before it became one of the second groups of butterflies to be listed under the US Endangered Species Act in 1980. [2] It is distinguished from other subspecies of G. lygdamus by its slightly different patterning on the underside of the wing and an earlier flight period. The subspecies was described from the southern slope of the Palos Verdes Peninsula in coastal Los Angeles County. [3]

The Palos Verdes blue butterfly was thought to be driven to extinction in 1983, primarily by development of its habitat. [2] The last three to six known individuals were seen and photographed in March, 1983, but the site they occupied was scraped shortly after for fire control. Then, in 1994, the butterfly was rediscovered by Rick Rogers, Rudi Mattoni, and Timothy Dahlum at the Defense Fuel Support Point in San Pedro, which is located on the northern (inland) side of the Palos Verdes Peninsula. [2] This new population lays eggs on an additional food plant (common deerweed, Lotus scoparius ) but shares physical and behavioral characteristics with the other now-extinct populations.

Biology

Taxonomy and systematics

Glaucopsyche lygdamus palosverdesensis is a subspecies of Glaucopsyche lygdamus (the "silvery blue"), a species of butterfly found throughout North America. There are currently 11 subspecies of silvery blue. G. lygdamus palosverdesensis was first described in the 1970s and was distinguished from other G. lygdamus by its faster and early flight, wing color and wing spot patterns. [4]

Morphology

The Palos Verdes blue butterfly has a wingspan of only 25–30 mm (0.98–1.18 in). The male has a bright silvery-blue dorsal wing outlined in a narrow line of black, while the female's dorsal wing is a more brownish-gray colour. Both males and females have gray ventral wings with dark spots surrounded by white rings. [5]

Habitat

G. lygdamus palosverdesensis persists particularly on the Palos Verdes Peninsula, 15 miles south of Los Angeles, in a coastal sage scrub habitat. This subspecies is locally monophagous, or particular to one species of food plant. The entire subspecies was originally thought to be particular only to the locoweed or rattlepod ( Astragalus trichopodus lonchus), but the population rediscovered in 1994 used common deerweed ( Lotus scoparius ) as its larval food plant. [4] These two types of plants are fast becoming scarce on the Palos Verdes Peninsula because of housing development. Retention of these larval food plants is essential for conservation of the Palos Verdes blue.

Life stages

Oviposition, laying of eggs on the larval food plant, occurs only once a breeding season for the Palos Verdes blue. There are at least four larval instars, or stages of development. After 7 to 10 days the larvae emerge and crawl to the base of the food plant where they pupate. Pupae remain in diapause until emerging as adults. [4] The flight period and reproductive period occur together, beginning in late January and ending in early May. It is rare to see the Palos Verdes blue far from its home food patch, but research shows that males cover more distance and have longer periods of flight. [4] Palos Verdes blues are a diurnal and panmictic subspecies. They are also non-migratory and very particular in their use of larval food plants. Their adult lifespan is only five days. [6]

Relationships with other species

Interspecific competition may occur with other lycaenid butterflies for the larval food plant. A mutualism between ants and larvae has been observed during the instars of butterfly development. G. l. palosverdesensis has a host-parasite relationship with its larval food plants, Astragalus lonchus and Lotus scoparius. Predation by western yellowjackets (Vespula pensylvanica) on the Palos Verdes blue has also been observed at the Defense Fuel Point location. [4]

Conservation

Laws

G. lygdamus palosverdesensis was listed as an "endangered species" by the United States Fish and Wildlife Service on July 2, 1980. This listing also included city-owned critical habitat, plus comments and recommendations for species conservation. Insects are not currently protected by California laws.

Threats

The main threat to the Palos Verdes blue has been habitat destruction due to weeds and rototilling, which has negative effects on the essential larval food plants. Recreational, commercial, or residential development of the Palos Verdes Peninsula is also a major concern in preservation of the food plants. [7]

Court case

In 1982, the city of Rancho Palos Verdes bulldozed the then most extensive known habitat of the butterfly to build a baseball field, an act believed to have been a principal cause of the die-off of the subspecies before its rediscovery in 1994. [8] [9] The US Fish and Wildlife Service maintained that the city was "well aware" of the butterfly and the site status. [10] According to the Los Angeles Times, the mayor of the city "said no one complained about butterfly destruction until grading had been completed." [10] In 1987, the city was charged by the federal government with violating the Endangered Species Act (ESA). [9] The case was dismissed later that year by a federal court, which said a municipality was not a person for purposes of the ESA, [11] and thus could not be held criminally responsible. [8] The following year, the US Congress responded by amending the act to include any "individual, corporation, partnership, trust, association, or any other private entity; or any officer, employee, agent, department, or instrumentality of the Federal Government, of any State, municipality, or political subdivision of a State, or of any federal government; any State, municipality, or political subdivision of a State; or any other entity subject to the jurisdiction of the United States." [11]

Reintroduction

The Palos Verdes Peninsula is split into the north and south slopes. On the north slope, reintroduction is suggested based on presence of deerweed (Lotus scoparius) and a native plant index number. The only habitat known so far on the north slope is the Defense Fuel Support Point location. The south slope has many more historic sites of Palos Verdes blue, which are all suggested for reintroduction, including any more sites containing locoweed (Astragalus). [4] Particular sites of reintroduction and rehabilitation of the Palos Verdes blue include Defense Fuel Support Point in San Pedro and the Linden H. Chandler Preserve. [4] In conjunction with other organizations, the Palos Verdes Peninsula Land Conservancy is installing and maintaining coastal sage scrub habitat on the slopes around the fuel tanks to benefit the blue butterfly. The Urban Wildlands Group, a nonprofit organization "dedicated to the conservation of species, habitats, and ecological processes in urban and urbanizing areas", conducts the captive breeding program. This program is a collaboration with Moorpark College and is directed by Moorpark College professor Dr. Jana Johnson.

Since that time, the Defense Logistics Agency, which operates the facility, has funded habitat restoration and a breeding program for the blue butterfly. Honey, produced on the premises, is provided to the captive rearing program so the butterflies are able to feed on the same food source as its wild companions. Major Jason Pike, an entomologist for the Defense Logistics Agency who has been monitoring the project, commented, "The military takes its responsibilities for endangered species on its properties very seriously, and DLA is pleased to provide support for the blue butterfly project."

Mass rearing

Mass rearing of the Palos Verdes blue has been taking place since rediscovery in 1994. The mass rearing is conducted for conservation purposes, reintroduction and prevention of extinction. The mass rearing takes place in "tent" cages containing both known larval food plants. [12] It has been variably successful. In 2008, 2,400 butterflies were raised in a laboratory at Moorpark College. In addition to accepting the conditions of the butterflies' protected status, landowners seeking to house the butterflies needed to prove they could provide sufficient numbers of "yellow-flowering deer weed plants." [13]

Modeling

Although population viability analysis models are often very important for predicting the outcome of conservation efforts, there have been many problems with using population viability analysis models to predict Palos Verdes blue populations. This type of modeling has proved inconclusive mainly because the Palos Verdes blue utilizes habitat so variably, depending on climatic and successional changes. [4] So far, the appropriate habitat has been hard to find, and expert intuition has often been wrong. Long-term population studies are not available to provide this information because of the many local extinctions and declining numbers of this subspecies. [4] For this reason, the subspecies long-term viability is very difficult to predict.

Key conservationists

Current conservation efforts are supported by the Defense Logistics Agency and the U.S. Navy and implemented by the Palos Verdes Peninsula Land Conservancy, The Urban Wildlands Group, and The Butterfly Project led by biologist Jana J. Johnson at Moorpark College. The Youth Environmental Service program of the Palos Verdes / South Bay Audubon Society and other volunteer groups have provided help weeding and establishing habitat for the butterfly. The Youth Environmental Service (YES) program started in 2012 and focuses on conserving the Linden H. Chandler Preserve, where they work on restoring native plants for the Palos Verdes blue butterfly.

See also

Related Research Articles

<span class="mw-page-title-main">Rancho Palos Verdes, California</span> City in California, United States

Rancho Palos Verdes is a coastal city located in Los Angeles County, California. The 2020 United States Census reported a population of 42,287. The city sits atop the bluffs of the Palos Verdes Peninsula, neighboring three other cities in the Palos Verdes Hills, namely Palos Verdes Estates, Rolling Hills, and Rolling Hills Estates. Rancho Palos Verdes is known for its dramatic views of the Pacific Ocean, Santa Catalina Island, and Los Angeles, as well as for its highly ranked schools, extensive horse and hiking trails, and for being one of the wealthiest ZIP codes in the United States in terms of household income and property prices.

<span class="mw-page-title-main">Xerces blue</span> Extinct species of butterfly

The Xerces blue is a recently extinct species of butterfly in the gossamer-winged butterfly family, Lycaenidae. The species lived in coastal sand dunes of the Sunset District of the San Francisco Peninsula in California. The Xerces blue is believed to be the first American butterfly species to become extinct as a result of loss of habitat caused by urban development. The last Xerces blue was seen in 1941 or 1943 on land that is now part of the Golden Gate National Recreation Area.

<span class="mw-page-title-main">El Segundo blue</span> Species of butterfly

The El Segundo blue is an endangered species of butterfly. It is endemic to a small dune ecosystem in Southern California that used to be a community called Palisades del Rey, close to the Los Angeles International Airport (LAX).

<span class="mw-page-title-main">Lycaenidae</span> Family of butterflies

Lycaenidae is the second-largest family of butterflies, with over 6,000 species worldwide, whose members are also called gossamer-winged butterflies. They constitute about 30% of the known butterfly species.

PVB may refer to:

<i>Acmispon glaber</i> Species of shrub

Acmispon glaber is a perennial subshrub in the family Fabaceae. The plant is a pioneer species found in dry areas of California, Arizona, and Mexico. It is commonly found in many areas including chaparral, coastal sand and roadsides at elevations below 1500 m.

<span class="mw-page-title-main">Karner blue</span> Endangered species of butterfly in northeastern United States

The Karner blue is an endangered species of small blue butterfly found in some Great Lakes states, small areas of New Jersey, the Capital District region of New York, and southern New Hampshire in the United States. The butterfly, whose life cycle depends on the wild blue lupine flower, was classified as an endangered species in the United States in 1992.

<span class="mw-page-title-main">Large copper</span> Species of butterfly

The large copper is a butterfly of the family Lycaenidae. L. dispar has been commonly arranged into three subspecies: L. dispar dispar, (single-brooded) which was commonly found in England, but is now extinct, L. d. batavus, (single-brooded) can be found in the Netherlands and has been reintroduced into the United Kingdom, and lastly, L. d. rutilus, (double-brooded) which is widespread across central and southern Europe. The latter has been declining in many European countries, due to habitat loss. Currently L. dispar is in severe decline in northwest Europe, but expanding in central and northern Europe.

<span class="mw-page-title-main">Heath fritillary</span> Species of butterfly

The heath fritillary is a species of butterfly in the family Nymphalidae. It is found throughout the Palaearctic from western Europe to Japan, in heathland, grassland, and in coppiced woodland. Its association with coppiced woodland earned it the name "woodman's follower" in parts of the UK. It is considered a threatened species in the UK and Germany, but not Europe-wide or globally.

<span class="mw-page-title-main">Coastal sage scrub</span> Shrubland plant community of California

Coastal sage scrub, also known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is within the California chaparral and woodlands ecoregion, of the Mediterranean forests, woodlands, and scrub biome.

<span class="mw-page-title-main">Mission blue butterfly</span> Subspecies of butterfly

The Mission blue is a blue or lycaenid butterfly subspecies native to the San Francisco Bay Area of the United States. The butterfly has been declared as endangered by the US federal government. It is a subspecies of Boisduval's blue.

<span class="mw-page-title-main">Smith's blue butterfly</span> Subspecies of butterfly

Smith's blue butterfly, Euphilotes enoptes smithi, is a subspecies of butterfly in the family Lycaenidae. This federally listed endangered subspecies of Euphilotes enoptes occurs in fragmented populations along the Central Coast of California, primarily associated with sand dune habitat in one case with a dune-based Maritime Coast Range Ponderosa Pine forest in the Carbonera Creek watershed in Santa Cruz County. The range of E. e. smithi is from Monterey Bay south to Punta Gorda.

<span class="mw-page-title-main">Native species</span> Species indigenous to a given area in geologic time

In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution during history. The term is equivalent to the concept of indigenous or autochthonous species. A wild organism is known as an introduced species within the regions where it was anthropogenically introduced. If an introduced species causes substantial ecological, environmental, and/or economic damage, it may be regarded more specifically as an invasive species.

<i>Glaucopsyche</i> Butterfly genus in family Lycaenidae

Glaucopsyche, commonly called blues, is a Holarctic genus of butterfly in the family Lycaenidae, found mainly in Palearctic Asia. For other species called "blues" see subfamily Polyommatinae and genus Plebejus.

<i>Glaucopsyche lygdamus</i> Species of butterfly

Glaucopsyche lygdamus, the silvery blue, is a small butterfly native to North America.

Lupinus elatus is a species of lupine known by the common name tall silky lupine. It is endemic to California, where it is known from the Transverse Ranges above Los Angeles, and possibly also from the southernmost slopes of the Sierra Nevada. Its habitat includes dry areas in the forests of the mountains. This is an erect perennial herb reaching a maximum height near 90 centimeters. Each palmate leaf is made up of 6 to 8 leaflets up to 8 centimeters long. The herbage is coated in silvery silky to woolly hairs. The inflorescence is a long raceme of flowers, each about a centimeter long and arranged in whorls. The flower is purple or blue with a pale yellow patch on its banner. It yields a legume pod 2 or 3 centimeters long. This is a host plant to the Southern California native butterfly subspecies known as the San Gabriel Mountains Arrowhead Blue.

<i>Icaricia icarioides</i> Species of butterfly

Icaricia icarioides, or Boisduval's blue, is a butterfly of the family Lycaenidae found in North America. This butterfly has 25 recognized subspecies.

<span class="mw-page-title-main">Palos Verdes Peninsula Land Conservancy</span> Non-profit organization in California

The Palos Verdes Peninsula Land Conservancy (PVPLC) is a non-profit organization that is based on the Palos Verdes Peninsula in southwestern Los Angeles County, California.

<i>Icaricia icarioides blackmorei</i> Subspecies of butterfly

Icaricia icarioides blackmorei, the Puget blue, is a butterfly native to the Puget Sound area in the northwestern U.S. state of Washington. It is a subspecies of Boisduval's blue.

<span class="mw-page-title-main">Bay checkerspot butterfly</span> Subspecies of butterfly

The Bay checkerspot is a butterfly endemic to the San Francisco Bay region of the U.S. state of California. It is a federally threatened species, as a subspecies of Euphydryas editha.

References

  1. Pelham, J. P. (2009). "Glaucopsyche lygdamus palosverdesensis". NatureServe. Retrieved March 7, 2023.
  2. 1 2 3 Mattoni, R. 1995. Rediscovery of the Palos Verdes endangered blue butterfly, Glaucopsyche lygdamus palosverdesensis Perkins and Emmel (Lycaenidae). Journal of Research on the Lepidoptera. 31 (3-4): 180-194.
  3. Ohanesian, Liz (July 15, 2021). "This Tiny, Blue Butterfly Is in Trouble. Local Conservationists Are Fighting to Change That". Los Angeles Magazine.
  4. 1 2 3 4 5 6 7 8 9 Lipman, Alison; Longcore, Travis; Mattoni, Rudi & Zhang, YinLan. 1999. Habitat Evaluation and Reintroduction Planning for the Endangered Palos Verdes Blue Butterfly. Final Technical Report to California Department of Fish and Game. 1-47.
  5. Arnold, R.A. 1987. Decline of the Endangered Palos Verdes Blue Butterfly in California. Biological Conservation. 40: 203-217.
  6. Isbell, C.M. 1996. Green Teens Save the Blues. Audubon. 98 (5): 102-105.
  7. Greenwalt, L.A. 1980. Listing the Palos Verdes Blue butterfly as an Endangered Species with Critical Habitat. Federal Register. Fish and Wildlife Service, Interior. 45 (129): 44939-42.
  8. 1 2 "An 'Extinct' Butterfly Flutters Back to Life". The New York Times. April 5, 1994. p. 4. Retrieved December 20, 2013.
  9. 1 2 Chambers, Marcia; Times, Special To The New York (April 4, 1987). "California city is charged in butterfly's demise". The New York Times. p. 8. Retrieved December 20, 2013.
  10. 1 2 Johnson, Ann (April 7, 1985). "Palos Verdes Blue Butterfly May Never Again Do Its Aerial Ballet". The Los Angeles Times. Retrieved December 20, 2013.
  11. 1 2 Smith, Andrew A; Moote, Margaret A; Schwalbe, Cecil (Fall 1993). "The Endangered Species Act at Twenty: An Analytical Survey of Federal Endangered Species Protection" (PDF). Natural Resources Journal. 33 (4): 1027–1075. Archived from the original (PDF) on December 20, 2013. Retrieved December 20, 2013.
  12. Mattoni, R., Longcore, Travis; Krenova, Zdenka & Lipman, Alison. 2003. Mass Rearing the endangered Palos Verdes blue butterfly (Glaucopsyche lygdamus palosverdesensis: Lycaenidae). Journal of Research on the Lepidoptera. 37: 55-67.
  13. "Rare butterfly experiences baby boom". UPI.com. March 18, 2008. Retrieved March 15, 2014.