[Market-farming] Pesticide resistance

Pat Meadows pat at meadows.pair.com
Mon Aug 25 11:28:07 EDT 2008


On Sat, 16 Aug 2008 04:39:40 -0700 (PDT), you wrote:

>Hello,Can anyone help me with with the following. How does an insect or a weed become resistant to a pesticide. What goes on in their system to creat this resistancy?Also, I know that there's no virucide out there, or at least used not to. Are there any known products out there now against plant viruses?ThanksAndrea Weber

I believe it's just natural selection working.  I.e., each generation of
insects (for example) will have a certain number that are slightly more
resistant to the pesticide than others, for one reason or another,
including chance mutations. Genes will mutate when hit by cosmic rays, as
well as for other reasons, and the earth is constantly being bombarded with
cosmic rays. 

The slightly more resistant ones have an advantage over the slightly less
resistant ones, so they will have more offspring.

Than the process is repeated for each successive generation. 

One really major problem with insects is that their generations are so
short; fruit flies are an outstanding example of this.  They reproduce much
faster than the proverbial rabbit.  But many, probably most, insects can
have a couple of generations per growing season.  Therefore, they can
fairly quickly become resistant to pesticides.  

I've used insects as an example, but exactly the same process (natural
selection) works in exactly the same way in plants.

Pat
-- northern Pennsylvania
Website:  www.meadows.pair.com/articleindex.html

"Rats and roaches live by competition under the laws of
supply and demand. It is the privilege of human beings to
live under the laws of justice and mercy." - Wendell Berry 



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