Ottawa (Dunrobin), ON Canada

20 April 2003   7:43PM EST  (top left)
9 May 2003   7:25PM EST  (top right)
4 May 2003   7:14PM EST  (bottom)

Pyreferra pettiti is the more common of the two species of Pyreferra known to occur in the Ottawa area.  The general color of this moth is orange, quite a vivid orange in fresher specimens.  Antemedial, medial and postmedial lines are darker orange to orange-brown, and for the most part fairly straight.  The postmedial line curves inward towards the base at the costal end, and has short dark lines extending outward where it crosses the veins, which are usually quite evident even in worn specimens.  The orbicular spot is round with a slightly paler filling, outlined in orange.  The reniform spot is usually less distinctly outlined, but has a dark spot in the lower (inner) end.  The subterminal line is usually followed by slightly darker shading towards the fringe.  When I have been able to persuade specimens to show their hindwings, the hindwing has usually been a pale straw yellow color. 

Because this species overwinters as an adult, specimens seen in the spring are somewhat worn, so that some markings may be fainter or absent, as compared to a fresh specimen.  The loss of wing scales due to wear can also affect the color, e.g., on the left wing of the specimen in the top right photo above.  Caution is needed, therefore, in distinguishing similar species when the specimens are not fresh, for example, Pyreferra pettiti and Pyreferra citromba (9930), both of which occur in my area.

According to Handfield (1999), the larvae of Pyreferra pettiti feed on birch species that are not found in my immediate area (Betula alleghaniensis and B. lenta) but also on Ostrya, and hop-hornbeam (Ostrya virginiana) is plentiful at my location.  Handfield notes adult flight seasons in my general area from early April through May, and from late September through early November.  I have observed this moth only once in the fall, however.

I have photographed this species in 2001 on 14 and 22 April, on 1 May, and on 19 September; in 2002, on 11, 12 and 14 April; in 2003, on 28 March, on 10, 11, 14, 18, 20, 27, 29 and 30 April, and on 4, 9, 10, 12, 14 and 17 May.