[NAFEX] Don't use Bt

david.maxwell at dal.ca david.maxwell at dal.ca
Fri Jun 19 11:59:52 EDT 2009

>     Instead, encourage Yellow Jackets and Bald Faced Hornets.  Both
>     spend 
> their days searching out larva to take back to their nest to feed
> their young.  You don't want them feeding their young with Bt poisoned
> grubs.  By the time insects develop resistance to Bt, you'll hope
> there are still some (flying) biological controls around.  Hopefully,
> you won't have killed them all off.
> Jim Fruth

I agree fully with encouraging vespids, but my understanding is that Bt is absolutely selective 
for caterpillars, and has no effect on any other insects.  In particular, it won't harm the wasps, 
and there is no risk of "killing off" anything other than the caterpillars eating your food crops.  
Nor will the "poisoned" caterpillars harm the baby wasps if Mom brings home the carcasses 
to feed them.

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