Mournful Duskywing (Erynnis tristis [Boisduval])
Wing span: 1 1/4 - 1 15/16 inches (3.2 - 4.9 cm).
Identification: Male has a costal fold containing yellow scent scales; female has a patch of scent scales on the 7th abdominal segment. Upperside of wings is dark brown-black with some transparent spots. Spots are larger in the female. Underside of hindwing is dark brown with a row of long white spots near the margin.
Life history: Males perch on hilltops all day to watch for females. Eggs are laid singly on new growth of the host plant. Caterpillars feed on young leaves and rest in shelters of rolled or tied leaves. Caterpillars of the last brood hibernate.
Flight: Three broods in Texas from March-April, June-July, and September-November.
Caterpillar hosts: Various oaks including coast live oak (Quercus agrifolia), blue oak (Q. douglasii), and valley oak (Q. lobata).
Adult food: Flower nectar.
Habitat: Oak woodlands.
Range: Northern California south through central Arizona, southern New Mexico, the mountains of Mexico, and Central America to Colombia. Strays to South Texas.
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.
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. 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