Tomas,
Best idea is to do nothing and see what bees survive. Breed from these and
you have the mite resistance. Good genes are found in about 10% of the bee
population. You may have to import some resistant strains from the US, but
your African bees may already be resistant.
Follow the experience of Brasil, keep producing that organic tropical
honey!
Regards,
Charles Andros
Linden Apiaries since 1973
Former NH/VT Apiary Inspector '78-’89
Walpole, NH 03608-0165 USA/EUA
603-756-9056