On Sat, 26 Jul 2003 09:46:24 +0100, David Hill wrote:

It was the banning of aldrin that has lead to the explosion of the problems
with Vine weevil

David, I'm quite sure that that's a gross oversimplification. In
chronological terms, I won't argue with you, but in terms of
cause and effect, I have to raise an eyebrow or three at this
analysis. There are all sorts of possible causes for the Vine
Weevil Explosion, and I'd put my money on the idea that all of
these causes have played significant roles.

Aldrin only came on the scene after the second world war,
probably in the mid-1950's. What was the vine weevil situation
like before aldrin was available?

I've read that the real culprit in the Vine Weevil Explosion was
the widespread adoption of peat-based composts instead of real
soil for potting, though I can't assess the validity of this
observation.

Another possibility is that overuse of petrochemical-derived
pesticides (not necessarily aldrin itself) eradicated the natural
predators of vine weevils, allowing their population to explode
when aldrin was taken off the market.

Yet another possibility: there has been no Vine Weevil Explosion;
it's just that we grow many more plants susceptible to them than
we used to. Cyclamen species, for example, are far more widely
grown now than they were just twenty years ago.


Footnote: has anyone else noticed that "weevil" is a conflation
of "we evil"?



--
Rodger Whitlock
Victoria, British Columbia, Canada