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market-farming - Re: [Market-farming] Imidacloprid - helpful info on characteristics

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  • From: Roots Farm & Karen Sutherland <rootsfarm AT cwdom.dm>
  • To: Market Farming <market-farming AT lists.ibiblio.org>
  • Subject: Re: [Market-farming] Imidacloprid - helpful info on characteristics
  • Date: Mon, 2 Aug 2010 10:54:17 -0400

My understanding is that a biologically active ingredient might not be seen on the list of active ingredients if it somehow is able to be loopholed into the class of  "inert" ingredients which don't have to be disclosed, but may be anything but "inert."

Best wishes to all,

Karen

Roots Farm
Organic Produce
Fruits, Roots, Vegetables & Herbs
CockraneDOMINICA
767-449-3038


On Aug 2, 2010, at 10:46 AM, <sunnfarm AT netscape.com> wrote:

The article says imidacloprid is found in most homeowner insecticides. Can someone name one of these homeowner insecticides. I don't spend much time in garden centers but I have yet to see inidacloprid on any shelf. I only see it sold to nursery and agricultural businesses. Since this product came on the market its been tightly controlled to prevent insect resistance. Which is why most ag pesticides are not avaliable to the general public. I would like to see more research on pollen/ nectar. When imidacloprid first came on the market and to this day when we apply it to greenhouse flowering plants like New Guinea Impatiens it will not kill insects in the flowers. Western flower thrips will die feeding in foliage but not from feeding in flowers. This finding lead us to conclude that imidacloprid does not pass into flowers of broadleaf plants until fruiting bodies have formed which is after pollen and nectar are gone... eternally perplexed Bob.

--- chriscreid AT yahoo.com wrote:

From: Chris Reid <chriscreid AT yahoo.com>
To: market-farming AT lists.ibiblio.org
Subject: [Market-farming] Imidacloprid - helpful info on  characteristics
Date: Mon, 2 Aug 2010 06:17:06 -0700 (PDT)

A University of Minnesota researcher discusses the amounts of imidacloprid found in pollen and nectar of plants treated with this chemical.

http://blog.lib.umn.edu/efans/ygnews/2010/08/imidacloprid-found-in-most-hom.html

PAN-UK cautions on the studied effects on beneficials, earth worms, and the ability of soil to break down leaf litter:
" Imidacloprid is acutely toxic to earthworms, for example the LC50 (the lethal concentration required to kill 50% of a test population) of the species Eisenia fetida is between 2 and 4 ppm in the soil. At lower concentrations, the activity of the enzyme cellulase in the soil, that allows the break down of plant litter is reduced by imidacloprid concentrations of 0.2 ppm.
   Soil application of granular imidacloprid is the most common. This is less harmful than the foliar spray because it is less likely to come into direct contact with non-target insects. However many natural enemies supplement their diet by feeding on plant material. As imidacloprid is systemic it can be translocated to the surface of the plant, increasing the chances of direct contact with insects on the plants. Laboratory tests have also shown that imidacloprid is acutely toxic to a variety of predatory insects including mirid bugs, ladybirds and lacewings."

For those with potable wells or high water tables, an important note:  I was surprised to learn that imidacloprid is in a category of pesticides with very high leaching potential.

Here is a link to Canadian Sierra Club rundown on some of the scientific findings regarding imidacloprid:
http://www.sierraclub.ca/national/programs/health-environment/pesticides/imidacloprid-fact-sheet.shtml

What least toxic methods have worked for others on control of cucumber beetles on squash?  I bought cucumber beetle lures this year and sticky traps, but so far insect pressure is very low.

Chris Reid
Stamford, CT








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