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 scolopendrina, 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
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.