Hello,
 
Paul Cronshaw wrote:
 
> He reminded me about an article I came across an article in our local
> Sunday THursday paper's Gardening section, entitled "Some bacteria can
> fight pests in the garden:
>
> "The velvety green cabbageworms that chew leaves of broccolli and cabbage
> to shreds can be stopped by making insect pests sick.  And the way you do
> this is by spraying the plants with Bt - short for Bacillus thuringiensis,
> a bacterium  that causes disease in certain insects.  Since Bt is toxic
> only to certain insects, it does not pose a danger to other creatures, such
> as birds, cats, dogs, humans, even beneficial insects.
>
> .. More recently, additional strains have been discovered that are toxic to
> insects besides caterpillars...Another strain, Bt var.aizawai, is deadly to
> the wax moth of beehives."
>
> How effective is Bt var.aizawai for control of wax moths?
 
This topic has been mentioned before on Bee-l.  In the UK there is a
product available called Certan based on BT.  I have used it and
found it to be very effective.  It is easy to use but in the
quantities that I have purchased quite expensive.  The makers claim
(and I think they are correct) that the product can be used with no
harm to bees on combs which are in use at the time of application.  I
seem to remember from the previous discussion that this product is or
has been available in the US and Canada.
 
Joe Hemmens