Other Common Names
Birch Dagger (
Entomological Society of Canada) - not recommended because another species,
Acronicta betulae already has that name, based on the meaning of its specific epithet
Identification
Adult: forewing creamy white to pale gray; bulge of postmedial (PM) line indented to form two small bulges; PM line bordered distally by slightly darker grayish shading, and proximally by a white band (sometimes indistinct); no basal or anal dash; reniform spot a black crescent; three or four black marks equally spaced along costa; terminal line composed of several black dots; hindwing white with diffuse dark discal spot, PM line, and shading
[adapted from description by Charles Covell]
Range
Newfoundland to British Columbia and adjacent northern states, south in the east to North Carolina and Kentucky
Season
adults fly from May to August
(1)Food
larvae feed on leaves of alder, birch, cherry, hickory, poplar, willow
Remarks
As of December 2006, the images labeled Unmarked Dagger (
Acronicta innotata) at
Larry Line's site appear to be
Acronicta betulae (note the sharp right-angle in the lower portion of the PM line).
See Also
Birch Dagger (
A. betulae) forewing has a sharp right-angle in the lower portion of the PM line, and the species has not been recorded in Canada
Internet References
live adult image (Dave Pelletier, Connecticut)
pinned adult image (A.W. Thomas, Canadian Forest Service)
pinned adult image (Insects of Cedar Creek, Minnesota)
pinned adult image (James Adams, Dalton State College, Georgia)
common name reference [Birch Dagger] (Entomological Society of Canada)
common name reference; PDF doc [Unmasked Dagger] (Saskatchewan Conservation Data Centre)
distribution in Canada list of provinces (U. of Alberta, using CBIF data)