basic question on Bt

[Liz Day]

Hi...

Is all Bt used for insect control the same?  I mean does any kind of Bt
kill any kind of caterpillar, or is it more complicated than that?  I have
wondered this for years, and of course the garden centers have no clue.

They also sell Bt for mosquito larvae, and I wonder if that can effect
leps too.

Somebody please enlighten me.....

Thanks.

Liz Day   
LDAY at iquest.net 
Indianapolis, Indiana, central USA - 40 N latitude, zone 5.

Where the &^$%@! promie larvae are all cocoons now as it's 90F every day.