Tetracis formosa (Hulst, 1896)

Family: Geometridae

Subfamily: Ennominae

Identification: Antenna nearly white dorsally, bipectinate in male, nearly filiform in female and densely setose ventrally. Head (frons gray), abdomen, legs gray to gray-brown, varying in color according to habitat. Montane specimens are mostly gray, high-desert specimens gray-brown, becoming paler at lower elevations in California. Wings: Base color pale gray to white; overall aspect gray to gray-brown because of overlying gray, brown, and dark brown scales. FW apex acute but barely falcate. AM and PM lines dark brown; PM line narrow, sinuate, with a narrow white outer border its entire length. AM line with narrow white border basad; AM line angles diagonally outward and upward from inner margin, terminating at the dark discal spot. MB at most only slightly darker than basal area. Submarginal area divided by narrow irregular dark brown band; in many specimens the wing color is paler distad of this band. Veins outlined in white. DHW paler centrally with darker shading along outer margin; dark brown median line irregular, us

Wing Span: 3.4-4.6 cm

Life History:

Flight: early September to late November

Caterpillar Hosts: Incompletely known. Prunus andersonii (Desert Peach)

Adult Food:

Habitat: Habitats range from desert riparian canyons (Colorado, Utah) to dry coniferous forest (Wyoming)

Range: Colorado, eastern Utah, and eastern Wyoming west to Caifornia and north to southern British Columbia and southern Alberta from 2850–7600’ (870–2320m).

Conservation:

NCGR:

Management Needs:

Taxonomy Notes: None.

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