Stiria dyari Hill

Stiria dyari Hill, 1924, Bull. So. California Acad. Sci., 23:183, pl. 3, fig. 3.

Diagnosis: Stiria dyari lives in southern California, northern Baja California, and western Arizona. The species resembles intermixta and rugifrons. However the forewing basal patch found in rugifrons and intermixta is absent from almost all specimens of dyari. Unfortunately a few females have a slight hint of a basal patch. The male hindwing is entirely pure white. A hint of brown along the outer margin is usually present in rugifrons and intermixta. Stiria dyari has a slightly brighter, cleaner appearance than rugifrons or intermixta (compare the colored figures of the three species). The forewing costa often has a slight light gray to white frosting of scales, although not consistently so. This frosting is also found in blanchardi. I have not found any consistent differences between the male genitalia of dyari and intermixta. However, the setose knobs of the costal margin of the sacculus tend to be less well developed, on average but not always, than in rugifrons and intermixta. Wing length from base to apex: mean = 15.45 mm., standard deviation = 1.02 mm., n = 10.

Distribution: Stiria dyari has been collected in southern California in the Mohave Desert region and at several localities in northern Baja California. It occurs in extreme southern Nevada and western and southwestern Arizona as far east as the Baboquivari Mountains. Some variability exists in the strength of the forewing postmedial and antemedial lines. Specimens without the lines are commoner than those with them. The female hindwing is slightly tinged with brown. Specimens from Arizona tend to be smaller than those from California and the forewing is not as bright. The forewing is slightly suffused with brown in Arizona specimens.

Adults have been collected from April to June in contradiction to the autumn flying habits of other known species. There is a single specimen in the LACM from California with a collecting date of October.

Identification Quality: Excellent

Larva: Unknown

Foodplants: Unknown

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