what season do the moths lay the iris borer eggs?

Do they lay eggs in just one season like spring or fall or throughout the spring, summer and fall?

Good question...I would like to know also.

I copied this info from a garden web site.


The most effective control relies on an understanding of the borer's life cycle. Borers begin life as eggs, laid on garden debris in the late summer and fall. Each spring, the borers larvae begin to hatch after the first two days of temperatures greater than 70 degrees. New England gardeners also have observed that hatch begins about the time the tulips bloom and it continues into June. The ¼ inch long larvae crawl up the iris leaves. Near the top they chew into the leaves. Then they eat their way down inside the leaves to the rhizomes, where they gorge themselves until they reach a length of about 1 to 1 ½ inches. Borers often will hollow out whole rhizomes causing fans to collapse and the remaining tissue to rot.

Some time in the summer the borer larvae change into pupae with a chestnut brown chrysalis or cocoon. These pupae reside in the soil for about a month and then a moth emerges and lays eggs. Borers in the pupae, moth and egg stages do not feed. Only as a larvae do they eat and do damage. At this stage they are most vulnerable to our efforts to control them.








This message was edited Sep 25, 2013 1:59 PM

the web site I quoted was the irisgarden.org

This was also stated
Basic Borer Control
"Keeping a clean garden is the first step in minimizing borer problems. In the summer and fall, the borer moths lay their eggs on the iris foliage or on the foliage of nearby plants. In the fall, cut back the iris leaves and remove them from your property if possible. This will reduce the number of borers hatching next spring.

In the spring, watch for the signs of borer infestation. A sharp eye for borer entry allows some gardeners to catch the borer in the leaf before it travels to the rhizome (simply pinch them in the leaves). If the borer has chewed its way further down the leaf, it maybe easier to remove a portion of the leaf then search for and destroy the borer. "

www.ComancheAcresIris.com
I just received a 2014 Newsletter #3 from Commanche Acres Iris farm and they included a section on what to do for iris bores. You might find it very helpful and informational.

I just signed up for the newsletter...hope I get the 2014 Newsletter #3.