bacillus thuringiensis shelf life

Paul Cherubini paulcher at concentric.net
Tue Jun 30 15:46:23 EDT 1998


Semjase,

Well I think we all agree with you that "natural" does not mean safe.
And I think we could all agree with your point that for marketing
reasons, a chemical company might purposely keep an ultra effective
product off the market (if one existed).

But the practical reality is that I can't think of any situation where
commercially available forumations of Bt have shown any promise of
providing long term control of any lep pest.  Consider golf courses,
city parks and cemeteries and their lawn moth problems. Turf pest
control managers can spray Bt on the same lawn time and time again for
several years and still be plaqued with lawn moths. As a rule, turf
managers don't use much Bt because they are dissappointed with its
effectiveness.

What I don't understand, as a practical matter,  is how you find it
conceivable that the same commercially available forms of Bt that havn't
worked well either on the farm or in the city, could somehow magically
cause widespread, long term mortality in a mourning cloak butterfly
population?

It's one thing to be philosophically opposed to using Bt because our
knowledge about its fate in the environment may not be 100% complete.
But it seems to me you are taking a big leap beyond this by flatly
stating (quote) "if a gardener uses this stuff he is making a grave
error." 

Paul Cherubini, El Dorado, California
paulcher at concentric.net


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