Synonyms and other taxonomic changes
Archiearis infans (Möschler, 1862)
Brephos infans Möschler, 1862
Explanation of Names
INFANS: a Latin word meaning "an infant"; refers to the adult's early emergence from a pupa in the spring, and is the basis for the common names The Infant and First-born Geometer
Numbers
The only species in this genus in North America.
Identification
Adult: forewing mottled brown with prominent white AM and PM patch at costa; AM patch sometimes extends as a band to anal margin; hindwing bright orange with variably developed black median and marginal bands; black patch extends from wing base to median area below discal cell; sexes similar
subspecies A. i. oregonensis, described from Port Orford, Oregon, is larger, paler, and occurs from southern BC to California.
Range
Alaska to Newfoundland, plus northern United States, south in the east to New Jersey, south in the west to California.
Habitat
Open wooded areas containing birch and alder.
Season
The main flight period is March to May but have been recorded through July.
Food
The larvae feed on leaves of birch, alder, poplar, willow; larvae that hatch before leaves are available in early spring may feed on flower catkins of the host tree.
Life Cycle
One generation per year; overwinters as a pupa.
Remarks
Adults may be seen flying in open woodlands on warm sunny days in early spring. They are fast fliers and normally difficult to capture, but occasionally sip moisture from damp sand or mud puddles; Song Sparrows have been observed to take advantage of this behavior to prey on the moths (Newman & Donahue 1967).
See Also
In the far west, they are superficially similar to
Dasyfidonia avuncularia, which has two well-defined continous black bands across hindwing, not patchy and broken as in
A. infans.
In the
Tiger Moth family, the highly variable
Leptarctia californiae might sometimes look very similar.
In the
Crambid Snout Moth family,
Pyrausta dapalis can look very similar.
Print References
Powell, J.A. & P.A. Opler, 2009.
Moths of Western North America. University of California Press, p. 204.; pl. 27, fig. 15.
(1)Internet References
live adult image (Cindy Mead, Michigan)
presence in California; list (U. of California at Berkeley)