Drusius Cloudywing (Thorybes drusius [W. H. Edwards])
Wing span: 1 1/2 - 1 3/4 inches (3.8 - 4.5 cm).
Identification: Forewing is pointed; lower half of hindwing has white fringe. Upperside is black-brown with very small, clear spots on the forewing. Male has a costal fold containing scent scales on the forewing. Underside is dark brown; hindwing with dark outlines instead of solid bands.
Life history: Not reported.
Flight: Several broods from April-August.
Caterpillar hosts: Cologania angustifolia and other Fabaceae.
Adult food: Flower nectar including that from Aloysia and Guardiola.
Habitat: Oak woodland, desert grassland, canyons, streamsides.
Range: Local and uncommon. Arizona to west Texas; south into Mexico.
Conservation: Not usually required.
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: None reported.
Bailowitz, R. A., and J. P. Brock. 1991. Butterflies of southeastern Arizona. Sonoran Arthropod Studies, Inc., Tucson, Arizona. 342 pages. Scott, J. A. 1986. The butterflies of North America. Stanford University Press, Stanford, Calif. 583 pages, 64 color plates. 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:
Ferris, C.D. and F.M. Brown. 1980. Butterflies of the Rocky Mountain States. University of Oklahoma Press. Norman. 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. Add Toliver, M., Holland, R., and S.J. Cary. 1996. Distributional data for New Mexico Butterflies. Privately published. Albuquerque, N.M.