American scientists have found a way to protect bees against varroa mites, tiny bloodsucking parasites that weaken and harm the adult bee population necessary for pollinating US$15bn worth of US crops each year and fuelling the country’s valuable honey industry.

Entomologists at the US Agricultural Research Service have discovered that some bees have a built-in genetic defence preventing mites reproducing in the honeycomb, where they generally prevent young bees developing.

When a queen bee with a “suppressed mite reproduction” trait is introduced to an infested hive its offspring’s gene’s can prevent mites breeding, curbing beekeepers’ dependence on chemical miticides. An untreated colony can be wiped out within two years of mite infestation.