Robert Mann wrote:

> I had not said synthetic pesticides *never* work.  To cite one
> case of apparent efficacy is hardly to comment at all on the fact that
> there have been many flops which is the point I was registering (not
> conceded by the chemofan, but well documented and indeed notorious
> amongst ecologists).

Likewise, Robert, flops occur in IPM programs that rely heavily on biological
control agents. In a college course I took in biocontrol
the professor stated about 90% of control attempts are failures.

Recently on the entomol-l list, Bill Warner offered the following instructive
comments on the curious lack of regulatory scrutiny in testing and
measuring the effects of biocontrol agents on non-target organisms:
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"Biocontrol agents are also pesticides under the definition of
the word, and many definitely have non-target consequences.
BUT, chemicals do not reproduce themselves, increase their range
and levels in the environment and potentially wipe out non-targets
such as the introduced chalcidoid/Pacific Island moth scenario or
mongoose/Hawaiian bird scenario (there are obviously
other potential explanations (human hunting, rats, habitat
destruction) for the latter)."

"The point remains, however; introducing any item that self
replicates should be prefaced by VERY intensive testing to assure
lack of non-target effects.  Problems with early pesticides gave
rise to the intense regulatory situation we have now.  Biocontrol
agents have been espoused by many of those in the
biocontrol business (I include many--if not most--of the researchers
along with the insectaries here) as being benign; a paradigm which
history has proven is not true!  TO THIS DAY there are species being
released without any understanding of effects on non-targets, only
measures of effect on the intended targets.  ALL pesticides (including
biocontrol agents) deserve scrutiny."