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Species Tetracis formosa - Hodges#6958

Synaxis formosa - Tetracis formosa Tetracis formosa - female Tetracis formosa - male Tetracis formosa - male Tetracis formosa Moth - Tetracis formosa - male Tetracis formosa Tetracis formosa
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Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Geometroidea (Geometrid and Swallowtail Moths)
Family Geometridae (Geometrid Moths)
Subfamily Ennominae
Tribe Ourapterygini
Genus Tetracis (Slant-Lines)
Species formosa (Tetracis formosa - Hodges#6958)
Hodges Number
Synonyms and other taxonomic changes
described in 1896 by Hulst, who originally placed it in genus Gonodontis
Synaxis formosa McDunnough, 1938,
The genus Synaxis is synonymized with Tetracis, Ferris and Schmidt, 2010 (a)
forewing length 17–23 mm
Adult -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, usually well-developed; discal spot small and dark. Wings ventrally very pale, lightly irrorated by brown scales. PM line, DHW median line, and discal spots strongly repeated; AM line indistinct, Ferris and Schmidt, 2010

a twig mimic
Colorado, eastern Utah, and eastern Wyoming west to Caifornia and north to southern British Columbia and southern Alberta from 2850–7600’ (870–2320m).
Habitats range from desert riparian canyons (Colorado, Utah) to dry coniferous forest (Wyoming)
Adults fly from early September to late November
Incompletely known. Prunus andersonii (Desert Peach)
It is possible that the California arid region populations represent a sibling species of T. formosa
See Also
Tetracis formosa separates from its congeners by its gray to gray-brown DFW color (paler at low elevation in Caifornia) and the following characters: narrow, wavy black or dark brown PM line; black or dark brown AM line that angles diagonally outward and upward from inner margin, terminating at the dark discal spot; dark submarginal line or band
Internet References
description, habitat, distribution (Strickland Entomological Museum, U. of Alberta)
presence in California; list of 10 specimen records with dates and locations (U. of California at Berkeley)
presence in Colorado; list (Paul Opler, Lepidoptera of Colorado National Monument)
distribution in Canada; list of provinces (CBIF)