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, F.M., Eff, J.D., and B. Rotger. 1957. Colorado Butterflies. Denver Museum of Natural History, Denver. Ferris, C.D. and F.M. Brown. 1980. Butterflies of the Rocky Mountain States. University of Oklahoma Press. Norman. Layberry, R.A., Hall, P.W. & Lafontaine, D.J., 1998. The Butterflies of Canada. University of Toronto Press, Toronto, ON. 280 pp. Opler, Paul A. 1999. Peterson Field Guide to Western Butterflies, revised edition. Houghton Mifflin Co., Boston, Mass. Stanford, R.E. and P.A. Opler. 1993. Atlas of Western USA Butterflies. Privately published, Denver, Colo. Tilden, J.W. and A.C. Smith. 1986. A Field Guide to Western Butterflies. Houghton Mifflin Co., Boston, Mass.