Explanation of Names
CINEREA: from the Latin "cinereus" (ashy), from "cinis" (ashes) - having the color of ashes, a light gray; refers to the forewing color
Adult: forewing light gray with low-contrast medium gray median and subterminal areas, or completely medium gray in some individuals; AM, PM, and terminal lines a series of black dots; small amounts of yellow or orange often present on forewing and top of thorax
hindwing light grayish-white with dark discal spot and terminal line of black dots
Larva: head brown; two small brown-barbed tubercles or "horns" on first thoracic segment; body green except for brown saddle-shaped areas edged in red on T1, A4, A5, A8, and A9 segments; anal prolegs modified into pair of long narrow tail-like projections ringed with brown, green, and red, giving the appearance of a forked tail
all of United States and southern Canada, plus Northwest Territories
adults fly from April to September in the south; May to August in the north
larvae from spring to fall in the south; July and August in the north
larvae feed on leaves of birch, poplar, willow
overwinters as a pupa; two generations per year in the south, one in the north
Light areas of forewing are white in F. borealis
, and pale tan or yellowish in modesta
; in occidentalis
, PM line is triple and continuous, and dark areas of wing are dark gray, providing good contrast against pale areas (compare images
of all 5 species)
The southwestern species, nivea
, has a mostly white forewing.
is found east of the Continental Divide.
(Dyar, 1890) is found in British Columbia south into Mexico.
Furcula vargoi Miller & Wagner, 2018 is found in Colorado.
Furcula wileyi (Dyrar, 1922) is found in Alberta south through Montana and Colorado.
Furcula nalli Miller & Wagner, 2018 is found in southern Texas.
(Neumögen, 1891) is found in Colorado, Utah and Arizona.
live adult images
plus description, food plants, and flight season (Lynn Scott, Ontario)
pinned adult image
plus US distribution map and common name reference (Paul Opler, Moths of North America; USGS) - Butterflies and Moths of North America
and food plants (Larry Line, Maryland)
live larva image
and description (U. of Missouri)
live larva images
(Lacy Hyche, Auburn U., Alabama)
live larva image
plus description and season (Jeffrey Miller, Caterpillars of Pacific Northwest Forests and Woodlands; USGS)