Re: vermin

Carol,
I am wondering if lasting 12 months means the chemical remains at high enough levels in the plant to be effective, or if they really mean the time they hope will elapse before pest populations will be noticed again? These chemicals are most likely moving in the transpiration stream to the surfaces of the plant where water is lost, and staying there. New surfaces would probably not become toxic unless the material remains available in the soil for continuous uptake over that long period. I do not know anything about the criteria for product approval, but I would guess that long persistence is not considered a good characteristic.

It is true that plants do move sugars and other products of metabolism from mature leaves to growing areas via the phloem, and this could occur with Imidocloprid as well, if it is stable inside the plant and can pass into the phloem. As for the safety of flowers and fruits, well, if true that means it doesn't move at all, or has a remarkably short lifetime, according to my calculus. :-)

The longer I go on, the more questions I have, so will keep quiet, except to say that I have never seen anything so remarkable as the common brown soft scale crawler. It is a little space alien - there is no doubt in my mind. Now to figure out what evil planet it came from!!!

Betty in South Bend



On Nov 13, 2004, at 12:20 PM, carol noel wrote:

Betty - thanks for the great information and warnings.

Bayer says their Tree and Shrub formula is supposed to last for 12
months, but I find 6 to 7 months on the outside for its' effectiveness I
have also been told(by someone who deals in pesticides) that it does not
migrate to the flowers or the fruit and that it is used on some orchard
crops...but I am skeptical of that. Aphids and mealies will live in the
flowers and umbels of my hoyas quite happily, though, while the rest of
the plant is clean.

Carol



From: Betty Hamilton <bkhamilton@earthlink.net> >Reply-To:
ferns@hort.net >To: ferns@hort.net >Subject: Re: [ferns] vermin >Date:
Sat, 13 Nov 2004 09:07:23 -0500 > >Hi Folks! > As a plant physiologist, I
would like to add a few things to the >discussion on Imidocloprid , and
other systemics. First, they are >strong chemicals, and should all be
used very carefully. It is not >just the pesticide that is dangerous.
The carriers and stabilizers >that accompany them may be more toxic than
the pesticide. Further, >the active agents may be volatile or unstable
in the soil, so they >may be available for absorption for only a short
time. Kyle may >have a better handle on this, but it is something to
keep in mind. > Second, as systemics, they have to be taken up by the
plant, and >that puts certain limitations on their effectiveness. Plants
which >are actively growing/transpiring will take up more active agent
than >those not in active growth. So bright light encourages uptake.
Abundant water is necessary to carry the chemical to the roots, at >the
time of application. Fertilization with systemic treatment may
stimulate root activity, which would increase uptake. To treat a >whole
plant requires that a large part of the root system be exposed >to the
systemic all at once, as there is no central switching yard >for water
movement in plants. > Third, insects not actively feeding while the
chemical remains in >the plant will not be affected. I do not know how
long the >systemics remain in the plant, but hope likely exceeds reality
in >this case. Any dormant or inactive scales will just sit out the
assault, and live to reproduce another day. > Just as a side note,
Imidocloprid is the active ingredient in the >popular Grub-X, used to
treat lawns for ..... grubs!!!!. The >populations of rose chafer grubs
(very similar to Japanese beetle >grubs) have gotten high in my garden,
causing damage to quite a few >ornamentals, including my hardy ferns.
Grub-X to the rescue, >followed by milky spore to establish lasting
control. I hope. > I know winter is upon us, but I am very reluctant to
use >Imidocloprid in the house. My plan is to do any treatments in warm
weather, outdoors, so the plants get their dose, and volitile
components have a chance to disperse before the plants come back
into the house. > > >Betty in South Bend, where the leaves are finally
falling, and >winter is just around the corner!!!! > > > >>Mary, >> 
They go go by the name "Provado Insect-pin" and are produced by
Bayer. They >>contain 2.5% Imidocloprid. >> >>I get them, but that
won't help you much, at the Boerenbond... >> >>Wim >> >> >>-----Original
Message----- >>From: owner-ferns@hort.net on behalf of Mary Gorton
Sent: Sun 11/13/2011 1:35 AM >>To: ferns@hort.net >>Cc: >>Subject: Re:
[ferns] vermin >>Wim, >> >>Where do you get 'sticks' of Imidocloprid and
what is the name >>under which >>it is sold? >> >>Mary Gorton >>
[demime 1.01d removed an attachment of type application/ms-tnef >>which
had a name of winmail.dat] >> 
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