Irises: My first iris borer!, 1 by laurief

laurief wrote:
OK, so not my first iris borer, but the first one I've ever seen in person. Ten years or so ago, I had a LOT of obvious borer damage in my iris beds, but I never actually managed to find one of the little uglies in action. I knew I had them in substantial numbers, but I must have dug my irises after the borers were already pupating. Never saw a one of them.

Then I started applying imidacloprid every spring, and borer damage virtually disappeared from my iris beds. Every now and then I'd find a rhizome along the outer edge of one of the beds with what appeared to be a borer hole in it, but again I never actually saw a borer.

This spring I applied imidacloprid to two of my beds before running out. I figured after using it for nearly 10 yrs, I must surely have wiped out the borer population in my iris beds, so I felt pretty safe not applying imidacloprid to the one remaining bed.

Over the last couple of weeks, I've been digging, dividing, and replanting all of the MDBs and SDBs in the non-treated bed, and LOW AND BEHOLD I found my first two living borers yesterday with their little heads stuck inside my dinky little rhizomes. As repulsed as I was by them, and as much as I'd prefer to think that I'd never have another borer in my iris beds, I'm actually glad to have finally seen the real live creatures for myself. They're smaller in diameter than I'd expected, and less pink. The head isn't as dark, either. Mostly, though, I'm surprised that they're not pupating yet. I would have expected them to be pupating this late in the season. I wonder, now, if this is normal timing for them or if they're running a couple of weeks late this year because of the prolonged winter and slow, cold spring.

All in all, I'm glad the little buggers finally made a personal appearance. I'm better acquainted with them now - better the enemy you know ... you know? And now I know that it is unwise to skip imidacloprid application in the spring. I won't be making that mistake again.

And now, (previously) alive and in person ... our nemesis, the iris borer ...