SIB - flower infestations
From: GWhite & LRader <bentfork@navix.net>
Chris Hollinshead wrote:
> From: "Chris Hollinshead" <cris@netcom.ca>
>
> > -----Original Message-----
> > From: Tmilchh@aol.com [T*@aol.com]
> > Sent: Wednesday, May 05, 1999 23:31
> > To: iris-talk@onelist.com
> > Subject: Re: [iris-talk] TB: Dieing Buds
> >
> > A friend of mine told me today that she had this problem and
> > found out that
> > there was a worm inside the iris below the blossum.
> > Annette in KY
> ---------------------------------------------------
>
> There is a good chance that this is the larvae of a fly which may infest the
> buds of various iris, particularly those such as siberians, japanese and
> species like versicolor and virginica and setosa, and eats the forming bud.
> For the most part this damage is not noticeable until the bud fails to open
> or opens with a very damaged bloom. A smaller bud than normal is
> occasionally symptomatic.
>
> I understand that this problem may be more prevalent in corn growing areas
> of the continent.
>
> The problem may be remedied with.......CYGON... which also is used for iris
> borer control.
> ...or removal and destruction of the infested bud.
>
> Christopher Hollinshead
> Mississauga, Ontario Canada zone6b
> AIS(Region 16), CIS, SSI
> Director-Canadian Iris Society
>
2 years ago in one of our gardens on our local spring tour, someone noticed that
a few of the siberian iris flowers were not opening properly and/or were
deformed/damaged. Upon closer inspection, we found a small larvae (about 1/4 to
1/2 inch in length) inside the flower. One of our youth members became quite
adept at finding these larvae in several siberian flowers during the rest of the
tour. A couple people thought that these were very young borer larvae, but this
was at bloom time (late May) and only the individual flower was affected. The
rest of the plant in every case was vigorous and there was no other sign of
borer damage either at that time or later that year. Since we are in
southeastern Nebraska (home of the Cornhuskers), and there are large cornfields
not far from the garden with the most infestation of this larvae, the tie to
corn growing areas as Chris mentioned may be true.
As for my own siberians, I have found these larvae only in a couple of
flowers (2 years ago, also), but my garden is within the Lincoln city limits and
hence a little further from large cornfields (but still within 1 mile of my
garden). Also, last year I sprayed with Cygon, and probably for that reason did
not see any sign of this problem then. This year I have sprayed about half of
my siberians with Cygon, but the other half have not been sprayed. I will do a
little experiment and see how these 2 groups fare with any infestations of this
fly larvae. One other point - As I recall, only a few flowers were affected on
any given siberian clump. And with a large clump with many bloom stalks, an
infestation, especially light one, will not be very noticeable if at all.
I have not directly observed these larvae in other irises, although I have a
vague memory of one Japanese variety that had several flowers that were deformed
or failed to open a couple of years ago also. I wonder if this larvae was the
culprit in that case. I will watch them more closely this year (although some
of the JI clumps have also been sprayed with Cygon). I have no first hand
knowledge of any problems related to bearded irises being affected by these
larvae in our gardens, though.
If anyone has more info on this insect (identification of species, natural
range, life cycle, etc) or its infestations on iris flowers, I for one would be
very interested in hearing about it. Thanks!
Gary White
Lincoln, Nebraska where our bloom season is at least 1 week ahead of normal
- a good number of TBs with bloomstalks on May 6 and our regional tour is May
22nd - will there be enough cool weather to slow their progress till then? If
not, the Region 21 tour may feature siberians and late TBs which will be a
really nice change of pace. At any rate, there Will be bloom.
------------------------------------------------------------------------
Did you know that
http://www.ONElist.com
More than 3.5 million people are using ONElist?
