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Ottawa (Dunrobin), ON Canada
20 April 2007 11:52PM EDT (top left)
13 April 2005 12:08AM EDT (top right)
14 April 2007 9:52PM EDT (bottom left)
1 April 2005 9:53PM EDT (bottom right)
My
initial identifications of Palceacrita vernata, also known as the
Spring Cankerworm Moth, were based on Covell (1984) and Handfield (1999).
Some information on the species has also been obtained from McGuffin, W.C.,
"Guide to the Geometridae of Canada (Lepidoptera), II. Subfamily
Ennominae. 2", Memoirs of the Entomological Society of Canada,
no. 101 (Ottawa: 1977).
The forewing of the male Paleacrita vernata is smoky
bluish gray, with faint brownish shades. Antemedial, medial and postmedial
lines are dark gray, generally visible at the costa and inner margin, but
otherwise frequently obscure. There is a pale gray patch at the apex,
defined by the beginning of the postmedial line at the inner edge, and by a line
angling inwards from the apex. A whitish zigzag subterminal line, narrowly
shaded with gray on the inside, and followed by a broader gray-brown shade on
the outside, carries on across the wing from the corner of the pale apical patch.
The vein running through the middle of the wing is usually highlighted with
black where crossed by the antemedial, medial and postmedial lines; it is
sometimes partially traced in white in the median. The hindwing is pale
gray and virtually unmarked. At rest, Paleacrita vernata usually
overlaps its wings as in the two photos at top, creating a narrower silhouette
than is usual with most geometrid moths. McGuffin (1977) notes a wing
expanse of 20 to 35 mm.
The female Paleacrita vernata is flightless, with
virtually non-existent vestigial wings.
According to Handfield (1999), the larva of Paleacrita
vernata has been reported to feed on maple, elm, birch, cherry and a
variety of other trees and shrubs. For my general area, he indicates the adult
moth flies from late March to about mid-May.
My records to date for Palceacrita vernata (each date
representing "the night of") are in the table below: |
