Ottawa (Dunrobin), ON Canada

29 May 2003   1:08AM EST  (top)
23 May 2003   9:23PM EST  (bottom left)
14 July 2003   12:24AM EST  (bottom right)

Epirrhoe alternata is similar in appearance to several other species in this group of the Larentiinae, with its wings cross-banded in the 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 clear white double post-medial band or line and, if one looks at the hindwings, it is evident that the hindwing pattern is more vivid and better defined than in similar species.  The innermost basal area is brown, without significant reddish tones.  The antemedial band is gray-brown, bounded on the inside by a single white line, and on the outside by a double white line.  The dark gray-brown median often shows a pattern of paler gray "bubbles"; the fairly large black discal dot is inside the largest such gray spot. The bright white of the double post-medial line is much more eye-catching than in other similar species.  It is followed by a pale grayish shading, which contrasts with the white scalloped subterminal line.  The dark apical patch is somewhat diffuse, and there is also a dark gray-brown patch below the apex, extending from the outer margin across the scalloped st line.  The hindwing carries a similar pattern of lines and shading, including the bright white double pm line and the white scalloped st line.  The darker, more intense colors of the forewing pattern, however, are absent on the hindwing.  Covell (1984) indicates a wingspan of 1.9 to 2.5 cm.

According to Handfield (1999), the larvae of Epirrhoe alternata feed on various species of bedstraw. He indicates two generations per year for my general area, with adult flight seasons from mid-May to early July, and from the second week of July to late August.

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