Monarch culture problems

Anne Kilmer viceroy at
Mon May 5 03:58:52 EDT 1997

James J. Kruse wrote:
> On Sun, 4 May 1997 Insectadv at AOL.COM wrote:
> > Not knowing what state you are in.  There are several states in the East that
> > are wholesale spraying "Bacillus thuringiensis" to try and control the gypsy
> > moth problem,  the product is also being used by some states and county
> > vector control groups to control mosquito.
> >
> > Insect Adventures
> >
> As I recall, the monarch culture problem was with adults. In a nutshell,
> Bt affects the digestive system of LARVAE by cutting it up with crystals.
> There are different Bt strains targeting Leps, Diptera, and Coleoptera,
> and sometimes combinations.  It is HIGHLY unlikely that Bt would be
> affecting adults in the manner described.
> I am far from a Bt proponent, but if we are going to be angry about Bt
> useage, lets be angry for the "right" reasons and not perpetuate rumor!
> Also, I have had cultures fail for years before Bt came along, and now it
> seems to be the only possible reason for failure!
> Cheers!
> Jim Kruse
> University of California at Berkeley
> Dept. of Environ Sci, Policy and Mgmt.
> Div. of Insect Biology
> Sperling Lab
> 201 Wellman Hall
> Berkeley, California, 94720-3113
> (510) 642-5114

I suspect that the problem with the monarch females was that they were 
squished too firmly when they were mated. Physical trauma could produce 
the symptoms described.
Is Bt communicable bug to bug? What happens to it in the bio-chain, when 
a bird or another bug eats a dying caterpillar? Or when another 
caterpillar eats it? 
If the mosquito type Bt also kills blackfly larvae, what else does it 
kill? And are we sure we want it to? Wholesale?
Anne Kilmer

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