Theona Checkerspot (Thessalia theona [Ménétriés])
Wing span: 1 1/4 - 1 3/4 inches (3.2 - 4.4 cm).
Identification: Upperside with dark checkered pattern. Black median stripe separates inner yellow-orange band and outer orange band. Underside of hindwing has alternating bands of orange and cream spots, all outlined in black.
Life history: Males patrol and sometimes perch to find females. Eggs are laid in groups on the host plant; caterpillars feed on the leaves. Third- or fourth-stage caterpillars hibernate.
Flight: Several flights from April-October in the Southwest, throughout the year in the tropics.
Caterpillar hosts: Ceniza blanca (Leucophyllum texanum and L. frutescens) in Texas, paintbrush (Castilleja species) in Arizona.
Adult food: Flower nectar.
Habitat: Desert foothills and canyons, subtropical scrub, limestone ridges, open oak or pinyon woodlands.
Range: Colombia north through Central America and Mexico to east-central Texas, southern New Mexico, and central Arizona.
Conservation: Not usually of concern.
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.
Note: Subspecies chinatiensis, the Chinati Checkerspot, is considered a separate species by some, but it blends completely to more typical theona.
Opler, P. A. and V. Malikul. 1992. A field guide to eastern butterflies. Peterson field guide #4. Houghton-Mifflin Co., Boston. 396 pages, 48 color plates. 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:
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.