Re: CULT: ROT/BORER?

rimat wrote:

> rimat wrote:
> >
> > some of my new irises are soft and yet are sending up leaves.  I
> > smooshed one open yesterday and found a critter about a half inch long
> > and kind of oval shaped --grey in color.  What is this creature and what
> > should I do?  Is it the dreaded borer?  and if it is rot or borer, how
> > come the leaves are up, growing and look helathy?
> > Rima  terra@catskill.net
> > upstate ny   zone 4
>
> I was hoping someone would respond to this query.  If it is borer, I
> need to do something soon.  and if it's just rot, I need to know what to
> do about that.  Can anyone help?
> Rima

Chris responds:

Rima; noting the area where you reside (upstate New York - USDA zone 4) I
seriously doubt that what you have found is an iris borer. They would not be
anywhere near this size at this early date. Iris borer at this time in your
area would be nearly microscopic in size having just hatched from the over
wintered eggs. As you are in an area of the continent affected by iris borer
it is now the perfect time to apply a first preventative spray of Cygon to
break the life cycle of any borer that may be present in your garden irises.
Follow up with a second spray in two weeks and you should be virtually borer
free this year.

As you noted these grey larvae are found in soft and mushy rotten rhizome
tissue. I know exactly what you refer to as I have found these myself.(often
upon examination there are found many more smaller less mature white larvae
throughout the rotten area)  They are nothing more than some sort of maggot
larvae. More serious is the presence of the rot. Be diligent in finding these
affected plants by touching the rhizomes. If soft, be suspicious and dig
deeper! Clean all rot out and disinfect with the Comet treatment of the liquid
bleach solution as much discussed here previously. The plant may not bloom
this year but should recover to increase and bloom next year. Left untreated,
the leaf fan will die back and the whole rhizome WILL rot over the next couple
of weeks.

--
Christopher Hollinshead
Mississauga, Ontario  Canada  zone6b
AIS(Region 16), CIS, SSI
Director-Canadian Iris Society
Newsletter Editor-Canadian Iris Society
e-mail:  cris@netcom.ca
CIS website:  http://www.netcom.ca/~cris/CIS.html
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