Promiscuous queen bees more likely to be executed

QUEEN bees are at a greater risk of execution by their workers if they mate with more than one male, research has found.

Queens normally only mate with one male, the father of the colony’s workers, in order to lower the effect of producing infertile offspring, known as “diploid males”.

These share one of the queen’s two alleles – different versions of the same gene – which emerge from cells around a month after the eggs have hatched.

It is at this stage that worker bees can kill a queen, as they sense that her offspring are defective.

In their experiment the University of Sussex and the University of Sao Paulo compared the fate of queen stingless bees, which are closely related to honeybees and bumblebees, in different hives in Brazil.

Scientists monitored colonies with 50 per cent diploid males – when the queen mated with one male who shared a sex allele with her.

They also monitored other colonies with 25 per cent diploid males – when the queen mated with two males, but only shared a sex allele with one.

As the queen was just as likely to be executed in both colonies, it showed that by mating with two males the queen actually doubled her chance of being executed. Francis Ratnieks, professor of apiculture (beekeeping) at the University of Sussex, said: “It is due to the genetics of sex determination in bees and the risk of what is known as ‘matched mating’.”

The study, published in the American Naturalist, helps biologists to understand why some species mate with multiple males, while others only remain with one.