obscura

G. obscura Davis and Pellmyr

Adult Characteristics

Wing expanse 10.5-19 mm. Forewings gray to light brown in the male, dark stramineous or with slight bronzy iridescence in the female, suffused with white ot whitish yellow, forming more or less distinct wing patterning. A rhomboid pale subtornal patch creates an arrowhead when the moth is at rest. Hindwing usually of the same shade as forewing or darker, without pattern.

Comparison with similar species

Lightly marked specimens can be mistaken for the sometimes coexisting G. politella. The light subtornal patch is usually present to some degree, even in the weakest of patterned specimens. Definitive identification can be established by checking for a minute pollex in obscura males as opposed to a prominent one in politella, and the absence in obscura of the much elongated seventh abdominal segment in female politella.

Hosts, oviposition, and larval feeding habits

The species feeds exclusively on several species of Lithophragma (Saxifragaceae). Eggs are laid in the floral calyx and in stem portion. Larvae do not feed on seeds, and are believed to mine in adjacent vegetative parts.

Geographic Distribution

Ranging from the drier southwesternmost part of Oregon to the San Garbriel Mountains aand southern Sierra Nevada of California.

Habitat

Occurring in grassy portions of open oak woodland, with or without a shrub component. Elevational range 300-1000 m. The species coexists with politella, solenobiella, powelli and suffusca.

Characteristic habitat; Monterey Co., California, USA.

Ecological notes

Even though this species visits Lithophragma flowers just like G. politella, and drink nectar from the flowers, there is no indication that they contribute to pollination (Pellmyr et al 1996).

References

Davis, D.R., O. Pellmyr & J.N. Thompson. 1992. Biology and systematics 
          of Greya Busck and Tetragma n. gen. (Lepidoptera: Prodoxidae). 
          Smiths. Contrib. Zool. 524:1-88.
Pellmyr, O., J.N. Thompson, J. Brown & R.G. Harrison. 1996. Evolution 
          of pollination and mutualism in the yucca moth lineage. 
          Amer. Nat. 148:827-847.

Holotype in USNM.

About this page

Olle Pellmyr
E-mail: pellmyr@ctrvax.vanderbilt.edu.
Dept of Biology, Vanderbilt University, Box 1812-B Nashville, TN 37235, USA

Title Illustrations: Male from Santa Barbara Co., California, and females from Douglas Co. and Josephine Co., Oregon.