Ottawa (Dunrobin), ON Canada

11 August 2005   9:10PM EST  (top left and top center)
8 August 2004   9:36PM EST  (top right)
4 June 2005   9:42PM EST  (bottom left and bottom right)
The pairs of "same date" photos are of single specimens photographed from two angles.

My thanks to Dr. Jean-François Landry of Agriculture Canada for identifying a number of my specimens of Swammerdamia caesiella.  For further information, I have relied on Internet resources, mainly related to the incidence of this species in Europe, but also including images from the All Leps: Barcode of Life web site.

Swammerdamia caesiella has mottled gray forewings that remind me of the pattern of fish scales.  A slightly darker band, most noticeable at the inner margin, usually crosses the wing about 1/3 of the way from the base.  There is a hint of white at the inner margin near the anal angle; photographs of spread specimens also show a white mark at the costa near the apex.  The head and thorax are white in all the specimens I've seen at my location, but a some Internet illustrations show a grayish thorax.  The hindwing is grayish.

In my experience, the dark fringe of the forewing sometimes shows a slight orange-brown reflection from the flash, suggesting on the basis of written descriptions that this could be the very similar species Swammerdamia pyrella.  The latter, however, has not been recorded from the Ottawa area, and all of the specimens submitted from my locations for expert examination have been identified as Swammerdamia caesiella.

According to Internet sources, the larva of Swammerdamia caesiella feeds on birch.  My observation records appear to suggest two generations per year in my area.

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