Gregorie: Fumidil-B is NOT fumigillin!!!
Fumidil-B is the combined preparation of the chemical "fumigillin" mixed with
an inert carrier to make mixing easier.
 
Do just what the directions say: 1 rounded teaspoon of Fumidil-B dissolved in
one gallon of 2:1 sugar syrup.
 
Let me help you get it mixed, or it will all float on the surface of syrup
like flour.
Mix the rounded teaspoon of fumidil-B in just 1-2 ounces of WARM (not HOT)
water and stir, stir, stir until dissolved.  Then mix that into the gallon of
2: 1 sugar syrup.
 
If you just try to dissolve the fumidil-B in the gallon of syrup, you will
still be stirring on Thanksgiving Day, and the fumidil-B will NOT be
dissolved.
 
How do I know?  I have fed about 100 colonies fumidil-B every November for
about 25-30 years; but I have HEALTHY bees.  It is a pain in the ___, but
healthy bees are worth the trouble.
                                                                                     George Imirie