Pyrgus ruralis lagunae
Scott, 1981
Laguna Mountains Skipper
T1T1Global Rank
HighThreat Impact
U.S. Fish & Wildlife Service, https://www.usa.gov/government-works
Identity
Unique IDELEMENT_GLOBAL.2.112102
Element CodeIILEP38021
Record TypeSPECIES
ClassificationSubspecies
Classification StatusStandard
Name CategoryInvertebrate Animal
Endemicendemic to a single state or province
KingdomAnimalia
PhylumArthropoda
ClassInsecta
OrderLepidoptera
FamilyHesperiidae
GenusPyrgus
Concept Reference
Pelham, J. P. 2008. A catalogue of the butterflies of the United States and Canada with a complete bibliography of the descriptive and systematic literature. The Journal of Research on the Lepidoptera. Volume 40. 658 pp. Revised 14 February, 2012.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2023-05-02
Change Date1998-09-01
Edition Date2023-05-02
Edition AuthorsSchweitzer, D. F. (2009), K. Hunting (2023)
Threat ImpactHigh
Range Extent<100 square km (less than about 40 square miles)
Number of Occurrences1 - 5
Rank Reasons
This taxon is restricted to four known disjunct populations on an isolated mountain top. These populations occur in mountain meadows which coincide with extensive grazing and recreational activities which serve to continue to depress populations.
Range Extent Comments
This species range is limited to a small area on Palomar Mountain, northern San Diego County, California, USA. Based on concave hull analysis of location data derived from California Natural Diversity Database element occurrences, the Range Extent of this species is about 29 km2.
Occurrences Comments
USFWS (2016) describes 4 extant occurrences all within the Palomar Mountain range.
Threat Impact Comments
Habitat destruction and degradation from overgrazing and trampling by cattle remain the primary reasons for the decline of the obligate host plant Horkelia clevelandii and hence the taxon. Trampling from excessive grazing removes host plants, compacts soil, and fragments habitat. Fire suppression in the region and on Palomar Mountain is resulting in vegetative community type changes and succession from meadow communities to sparse forest. These conversions are responsible for the loss of habitat in some parts of this taxon’s range. A secondary threat to this taxon are recreational activities including hiking, backpacking, and other day use activities. The host (and probable secondary host plants) for this taxon are restricted to meadows which are prime recreational lands in the Palomar Mountain area. The effects of climate change including more frequent and prolonged drought and altered precipitation regimes likely impact this taxon. Asynchronous phenology of host plants and emergence of larval stages of this taxon are expected with the prolonged effects of climate change. Prolonged and intense drought is likely the reason for the extirpation of the Laguna Mountain populations (USFWS 2016).
Ecology & Habitat
Habitat
It occupies montane meadow habitats between 4,000 and 6,000 feet altitude within yellow pine forests. The larvae of the Laguna Mountains skipper feed solely on Cleveland’s horkelia, a plant that is similarly restricted to montane meadows in San Diego County and the neighboring Riverside County. A major factor in the decline of the Laguna Mountains skipper is the decreasing abundance of their hostplant due to grazing and trampling by cattle (Black and Vaughan 2005e).
Terrestrial Habitats
Forest - ConiferGrassland/herbaceous
Other Nations (1)
United StatesN1
| Province | Rank | Native |
|---|---|---|
| California | S1 | Yes |
Threat Assessments
| Threat | Scope | Severity | Timing |
|---|---|---|---|
| 2 - Agriculture & aquaculture | Large (31-70%) | Moderate or 11-30% pop. decline | High (continuing) |
| 2.3 - Livestock farming & ranching | Large (31-70%) | Moderate or 11-30% pop. decline | High (continuing) |
| 2.3.1 - Nomadic grazing | Large (31-70%) | Moderate or 11-30% pop. decline | High (continuing) |
| 6 - Human intrusions & disturbance | Large (31-70%) | Slight or 1-10% pop. decline | High (continuing) |
| 6.1 - Recreational activities | Large (31-70%) | Slight or 1-10% pop. decline | High (continuing) |
| 7 - Natural system modifications | Large (31-70%) | Moderate or 11-30% pop. decline | High (continuing) |
| 7.1 - Fire & fire suppression | Large (31-70%) | Moderate or 11-30% pop. decline | High (continuing) |
| 7.1.2 - Suppression in fire frequency/intensity | Large (31-70%) | Moderate or 11-30% pop. decline | High (continuing) |
| 11 - Climate change & severe weather | Pervasive (71-100%) | Moderate or 11-30% pop. decline | High (continuing) |
| 11.2 - Droughts | Pervasive (71-100%) | Moderate or 11-30% pop. decline | High (continuing) |
Roadless Areas (2)
California (2)
| Area | Forest | Acres |
|---|---|---|
| Barker Valley | Cleveland National Forest | 11,940 |
| Cutca Valley | Cleveland National Forest | 14,530 |
References (10)
- Black, S. H., and D. M. Vaughan. 2005e. Species Profile: <em>Pyrgus ruralis lagunae</em>. In Shepherd, M. D., D. M. Vaughan, and S. H. Black (Eds). Red List of Pollinator Insects of North America. CD-ROM Version 1 (May 2005). Portland, OR: The Xerces Society for Invertebrate Conservation. https://xerces.org/laguna-mountains-skipper/
- Garth, J.S. and J.W. Tilden. 1986. California Butterflies. University of California Press.
- Opler, P. A., and A. D. Warren. 2002. Butterflies of North America. 2. Scientific Names List for Butterfly Species of North America, north of Mexico. C.P. Gillette Museum of Arthropod Diversity, Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, Colorado. 79 pp.
- Pelham, J. P. 2008. A catalogue of the butterflies of the United States and Canada with a complete bibliography of the descriptive and systematic literature. The Journal of Research on the Lepidoptera. Volume 40. 658 pp. Revised 14 February, 2012.
- Pelham, J.P. 2023. A catalogue of the butterflies of the United States and Canada. Revised 15 February 2023. http://butterfliesofamerica.com/US-Can-Cat.htm
- Shepherd, M. D., D. M. Vaughan, and S. H. Black (Eds). 2005. Red List of Pollinator Insects of North America. CD-ROM Version 1 (May 2005). Portland, OR: The Xerces Society for Invertebrate Conservation. online. available: www.xerces.org
- U.S. Fish and Wildlife Service (USFWS). 1994. Proposed Rule to list the Saint Francis' Satyr [<i>Neonympha mitchellii francisci</i>] as Endangered. Federal Register 59(74):18350-18353.
- U.S. Fish and Wildlife Service (USFWS). 1997. Proposed rule to list three aquatic snails as endangered, and three aquatic snails as threatened in the Mobile River basin of Alabama. Federal Register 62(201):54020-54028.
- U.S. Fish and Wildlife Service (USFWS). 2007. Laguna Mountains Skipper (Pyrgus ruralis lagunae), 5-year review: summary and evaluation. USFWS, Carlsbad, California office. Online. Available: http://ecos.fws.gov/docs/five_year_review/doc1158.pdf
- U.S. Fish and Wildlife Service (USFWS). 2019. Recovery Plan for Laguna Mountains Skipper (<i>Pyrgus ruralis lagunae</i>). U.S. Fish and Wildlife Service, Pacific Southwest Region, Sacramento, California. ix + 60 pp.