IRISBORER - CONTROL

In a message dated 97-06-22 03:09:14 EDT, you write:

>Anyway, from what I have gleaned about borers, most people who have them
>prefer Cygon.  I'm not sure just when to apply it.  Some people have
>talked about temperature.  When the temperature reaches a certain degree
>then you should spray.

Irisborer are probably the biggest problem we have to face in the eastern US
(except for soft rot...but I don't have any solid advice for that!)  The
borer is the larva of a night-flying and very shy moth.  The life cycle goes
like this..... despicable moth flies into your iris patch and lays her eggs
on iris debris (a good cause for total clean up in the fall.... and very
early clean up in the spring).  The eggs hatch in early spring and the worms
released burrow into your precious iris... usually along a leaf somewhere
(don't ask me why we never see the worms between the hatch and the entry....
I never have, anywho).  So, being a totally charming life form, the worms
then eat each other... a kind of insectoid Donner Party... ending up with one
superworm.  The superworm eats its way down the leaf sheath to the rhizome...
growing all the time... and enters the rhizome.   While there, it hollows it
out... exits into the soil and finds a place to pupate.... which becomes a
moth and so on.

SO .... the controls are 3-fold... and you can use any combination or the
ones that appeal.

1.  Your iris bed should be extremely clean.  No dead foliage should be
allowed to linger... and both a fall total clean and a very early spring
cleaning are imperative!  I know one hybridizer who actually BURNS his iris
field each year in the late fall.

2.  You should get right down and personal with your plants.... especially if
you're of the organic persuasion.  Watch for any telltale signs...  notched
leaves.... shiny appearance at the base of the fan... frass or sawdust.  If
you see anything like this... you can pinch the bejesus out of the leaves and
hope you mash the dasterdly grub... or you can go in with a knife and drag it
out of your iris and send it to it's maker in a bucket with clorox water.

3.  You need to set up a spraying program with Cygon 2E.  This systemic
pesticide is applied 3 times in the spring (and proactively)... once at the
first sign of iris growth (or when the tulips bloom), 10 days later and 10
days later.  This should rid you of almost 100% of the critters... BUT - you
should be very aware of the cautions about using Cygon and take the necessary
precautions.  ONE NOTE.... THIS IS NOT A SPRAY.  I would never consider
spraying with Cygon... we use it as a drench around each rhizome, which is
taken into the plant, making it toxic.  I have personally noticed no
reduction in wildlife (or soil life) after 10 years of using Cygon.  Plenty
of birds, worms and striped and/or bushy tailed rats.

SO.... that's my irisborer story.  It IS curious that little if any research
has been done on controllling the moth!  In fact, at the AIS Board meeting,
the person who manages the scholorship and grant fund wondered why no-one
ever applies to do a study on irisborers... certainly one of the scourges of
the east!

Kathyguest.... bracing
East Aurora, NY where the martagon lilies are to DIE for!
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