Two-banded Checkered-Skipper (Pyrgus ruralis [Boisduval])
Wing span: 1 - 1 1/8 inches (2.5 - 2.9 cm).
Identification: Upperside is light-to-blackish brown; forewing has squarish white spots; hindwing usually has 2 rows of white spots. Underside is brown or gray with dull spots that are often obscure. Male has a costal fold enclosing scent scales on the forewing.
Life history: To find receptive females, males patrol and sometimes perch close to the ground in valley bottoms or swales. Females lay eggs singly on the host plant. Caterpillars make a webbed leaf nest in which they live and feed.
Flight: One brood from April-July.
Caterpillar hosts: Herbaceous plants in the rose family (Rosaceae) including Drummond's potentilla (Potentilla drummondii), dusky horkelia (Horkelia fusca), Santa Rosa horkelia (H. tenuiloba), Cleveland's horkelia (H. bolanderi clevelandii), and probably others.
Adult food: Flower nectar.
Habitat: Forest clearings, meadows, pastures, streamsides; from sea level to 10,000 feet.
Range: Inconspicuous, usually local and uncommon. South in the mountains from British Columbia and Alberta to southern California, Arizona, and New Mexico.
Conservation: The Laguna Mountains skipper (subspecies lagunae) is on the Endangered Species list and needs careful study of its conservation needs.
The Nature Conservancy Global Rank: G4 - Apparently secure globally, though it might be quite rare in parts of its range, especially at the periphery.
Management needs: Habitat of the Laguna Mountains skipper requires periodic disturbance such as light grazing and small controlled burns.
Levy, J. N. 1994. Status of the Laguna Mountains skipper butterfly (Pyrgus ruralis lagunae J. Scott). Biological Survey and Analysis prepared for the Forest Service, United States Department of Agriculture. Scott, J. A. 1986. The butterflies of North America. Stanford University Press, Stanford, Calif. 583 pages, 64 color plates. Stanford, R. E. and P. A. Opler. 1993. Atlas of western USA butterflies including adjacent parts of Canada and Mexico. Denver and Fort Collins, CO. Tilden, J. W. 1986. A field guide to western butterflies. Houghton-Mifflin Co., Boston, Mass. 370 pages, 23 color plates.
Author: Jane M. Struttmann
State and Regional References:
Brown, J.W., Real, H.G., and D.K. Faulkner. 1992. Butterflies of Baja California. Lepidoptera Research Foundation, Beverly Hills, Calif. Comstock, J.A. 1927. Butterflies of California. Privately published, Los Angeles, Calif. [Facsimile available from Entomological Reprint Specialists, Los Angeles, Calif.] Dameron, W. 1997. Searching for butterflies in southern California. Flutterby Press, Los Angeles, Calif. Emmel, T.C. Editor. 1998. Systematics of western North American butterflies. Mariposa Press, Gainesville, Florida. Emmel, T. C. and J. F. Emmel. 1973. The Butterflies of Southern California. Natural History Museum of Los Angeles County Science Series No. 26. Garth, J.S. and J.W. Tilden. 1986. California Butterflies. California Natural History Guide 51. University of California Press, Berkeley and Los Angeles. Langston, R.L. 1981. The Rhopalocera of Santa Cruz Island, California. Journal of Research on the Lepidoptera 18: 24-35. Miller, Scott E. 1985. Butterflies of the Califorenia Channel Islands. Journal of the Research on the Lepidoptera 23: 282-296. Opler, Paul A. 1999. Peterson Field Guide to Western Butterflies, revised edition. Houghton Mifflin Co., Boston, Mass. Orsak, L.J. 1977. The Butterflies of Orange County, California. Museum of Systematic Biology, University of california, Irvine. Stanford, R.E. and P.A. Opler. 1993. Atlas of Western USA Butterflies. Privately published, Denver, Colo. Steiner, J. 1990. Bay Area Butterflies: The Distribution and Natural History of San Francisco Region Rhopalocera. Hayward, Calif.: Hayward State University, Masters Thesis. Tilden, J.W. and A.C. Smith. 1986. A Field Guide to Western Butterflies. Houghton Mifflin Co., Boston, Mass. Tilden, J.W. 1965. Butterflies of the San Francisco Bay Region. California Natural History Guide 12. University of California Press, Berkeley and Los Angeles.