Ottawa (Dunrobin), ON Canada

31 July 2000   1:25AM EDT

Colobochyla interpuncta has a darkish gray to brown forewing crossed by three distinct lines.  The antemedial line is yellowish, and often less obvious than the other two visible lines.  The medial and postmedial lines are yellow toward the inside and dark reddish brown toward the outside, each forming a smooth curve across the wing.  The postmedial line terminates at the apex of the wing.  There may be evidence of darker shading between the postmedial line and the subterminal line, although the specimen illustrated above does not show this.  The reniform spot is usually visible as black spot outside the medial line, but the orbicular spot is smaller and less obvious.  The hindwing is grayish.  Covell (1983) indicates a wingspan of 2 to 2.4 cm.

When I first see this species each year, I have to think hard for a moment about its identity, as it reminds me somewhat of the geometrid Metanema determinata (Hodges 6820) even though the two are actually quite different in appearance and resting position.

According to Handfield (1999) the literature indicates that larvae of Colobochyla interpuncta have been reared on willow, but the host plant chosen in the wild is apparently unknown.  For my general area, Handfield indicates two generations per year, with adult flight seasons from about mid-June to mid-July, and from late July into the second half of August.

I have recorded this species in 2000, on 30 July; in 2001, on 19, 22 and 29 July; in 2002, on 4 and 14 June, on 3 July, and on 2, 4 and 5 August; in 2003, on 11 and 12 June, and on 11 August.