Ottawa (Dunrobin), ON Canada

22 June 2004   12:40AM EST  (top left)
9 August 2003   10:27PM EST  (top right)
24 June 2006   11:06PM EST  (center)
16 June 2006   10:05PM EST  (bottom left)
16 June 2006   11:19PM EST  (bottom right)

Identification of Marathyssa inficita is made somewhat challenging by this moth's habit of resting with its wings furled.  With its abdomen arched outward, it often comes to rest upside down, as in the photo at top right.  Moreover, those of us photographing unposed live specimens are often frustrated by this moth's reluctance to open out its wings.

Marathyssa inficita, also known as the Dark Marathyssa, has a gray forewing, shaded to varying degrees with gray-brown.  There is brighter reddish brown shading in the basal area, preceding the double black antemedial line.  The median is crossed by a diffuse line of gray-brown to reddish-brown.  The double black postmedial line is most evident at the inner margin and in the lower half of the wing, and consequently are not usually visible when the wings are furled at rest.  At the costa, however, there is a distinctive reddish brown patch a short distance in from the apex, followed by a whitish subterminal line.  The hindwing is fairly dark gray-brown with a distinctive gray streak outward from the base in the lower half of the wing, and a patch of reddish brown at the outer margin.  Covell (1984) indicates a wingspan from 2.5 to 2.8 cm.

According to Handfield (1999), the larvae of Marathyssa inficita feed on staghorn sumac and poison ivy.  He indicates two generations per year for my general area, with adult flight seasons from the beginning of June to about mid-July, and from early August to late August.

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