Beesource Beekeeping Forums banner

Bt kills Varroa Mites

1972 Views 5 Replies 5 Participants Last post by  Flyer Jim
Reading papers on corn pollen I came across papers showing that Bt, Bacillus thuringiensis, kills varroa but is harmless to bees.
GMO corn with Bt genes, created to kill pests that eat corn, has Bt in the pollen that bees collect and feed to larvae. Fortunately, this seems to have no negative effects on the bees at all. Looking at some of the papers linked in this study I happened upon several that studied the effects of Bt on mites, and it appears to be very effective in vitro (in the lab). Was not able to find much other info or whether anyone had tested this in the field.
Effects of Bacillus thuringiensis strains virulent to Varroa destructor on larvae and adults of Apis mellifera
1 - 6 of 6 Posts

· Registered
447 Posts
Bt can only kill if ingested. And passthrough control methods won't work because it is the action of gut enzymes combined w/ conformational changes due to gut pH that activates the killing power of the Bt protein. That is why there are different strains for different target species--and why it is nontoxic to vertebrates (low pH vs high pH digestion).

I'm sure you could get it to work in vitro if you have mite colonies that are being reared on artificial substrate (feed) where you could mix the Bt in and have it remain stable until ingestion. One of those scenarios where lab does not equal nature.

Maybe mites consume some water from hive condensate? I assume not but do not know. If they do then spraying comb could work theoretically.
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.