Ottawa (Dunrobin), ON Canada

8 May 2005   9:02PM EST  (top)
9 May 2005   9:30PM EST  (bottom)

Xanthorhoe lacustrata is one of half a dozen species of Xanthorhoe known to occur in the Ottawa area (J.D. Lafontaine, pers. comm., 2001).

Xanthorhoe lacustrata has light gray to light grayish tan forewings, with many cross lines and bands of color in a pattern characteristic of many of the Larentiinae or so-called carpet moths (so called, I suspect, because the pattern of lines and bands is reminiscent of the border patterns of some oriental carpets). It can be distinguished from other similar species by its dark brown median area, and the indentation of the post-medial line above the outward-pointing "tooth" of the median. The basal area is reddish brown, bounded by a fairly wide antemedial band that curves relatively smoothly across with wing without any major bulges or angles. The postmedial line extends straight downward from the costa for a short distance, then curves inward before it angles outward to form the tooth of the median.  In other similar species, the shape of the pm line is different enough to provide a useful clue to identification.  Much of the subterminal area is dirty beige in color.  The dark apical patch is brownish and somewhat irregular in shape.  There is a brownish dark patch in the subterminal area below the apex, quite diffuse in the specimens I have seen.  The hindwing is grayish with a fainter pattern of cross-lines.   Covell (1984) indicates a wingspan of 2.0 to 2.6 cm.

According to Handfield (1999), the larvae of Xanthorhoe lacustrata feed on a variety of plants, including impatiens, birch, tamarack, various species of raspberry and other brambles, hawthorn and willow. He indicates two generations per year for my general area, with adult flight seasons from the the end of April to the end of May, and from early July to late August.

My records to date for Xanthorhoe lacustrata (each date representing "the night of") are in the table below: