Muddymitts said:
Sue (sooby) -- I didn't know that Iris Borers were that far north? 
I'm so sorry. They're very discouraging -- but there are ways to eliminate them so that you can enjoy your Irises. Folks on this forum can help you!!
Yes, unfortunately, they do occur here. There's a map, not necessarily complete, showing the range of iris borer reports to Bugguide:
http://bugguide.net/node/view/...
Something to bear in mind with suggestions for control information, Marion and I are both in Ontario where most "chemical" pesticides are banned for homeowner use by the provincial government. I believe the Bayer Grub Control that Leslie mentioned contains the same neonicotinoid insecticide as Merit (imidacloprid)? We can't get/use that here, or any other systemic insecticide. Squishing is legal though
