Borer: cover iris Sept-Nov???
Using the knowlegde of life history of Borer:
Has anyone tried covering iris from Sept-Nov with a white
fibrous cloth [often used for protecting against vegetable pests]?
Virginia from Georgia
"Here is an excerpt from a later Cornell Bulletin [July 1935 (again no
bibliography!)] that may give you a starting point.
CORNELL EXTENSION BULLETIN 324 INSECT PESTS OF IRIS Grace GRISWOLD
The iris borer (Macronoctua onusta Grt.) is probably the most injurious
.. The moths usually appear about September ... into November.
They mate, and the females lay eggs which do not hatch until the
following spring. ...eggs laid on wire screen. Only in one instance
were any eggs laid on fresh green iris leaves.
..It eventually leaves the rhizome and goes into the soil to
pupate. Pupation lasts for about five weeks and, as previously stated, the
adult moths begin to appear about the middle of September.
Iris plants should be carefully watched during the summer months. If there
In fighting the iris borer a thorough clean-up of the garden in
..late fall and spring. Another method of control is to spray ...