Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Calendar
Upcoming Events

Discussion, insects and people from the 2018 BugGuide Gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama

Photos of insects and people from the 2011 gathering in Iowa

Photos from the 2010 Workshop in Grinnell, Iowa

Photos from the 2009 gathering in Washington

TaxonomyBrowse
Info
ImagesLinksBooksData

Species Tetracis formosa - Hodges#6958

Hodges # 6958 - Synaxis formosa - Tetracis formosa - male Synaxis formosa - Tetracis formosa Synaxis formosa - Tetracis formosa
Show images of: caterpillars · adults · both
Classification
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
6958
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)
Size
forewing length 17–23 mm
Identification
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
Range
Colorado, eastern Utah, and eastern Wyoming west to Caifornia and north to southern British Columbia and southern Alberta from 2850–7600’ (870–2320m).
Habitat
Habitats range from desert riparian canyons (Colorado, Utah) to dry coniferous forest (Wyoming)
Season
Adults fly from early September to late November
Food
Incompletely known. Prunus andersonii (Desert Peach)
Remarks
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
pinned adult image and photos of related species by Jim Vargo (Moth Photographers Group)
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)