Australasian Science: Australia's authority on science since 1938

Male Bees Protect Females from STDs

The seminal fluid of male bees kills the sexually transmitted fungus Nosema apis, protecting queen bees from sexual transmission of the parasite.

Prof Boris Baer of The University of Western Australia’s Centre for Integrative Bee Research said that the study, published in Proceedings of the Royal Society B (, found that male honey bee semen produced protein molecules that cause the Nosema apis fungus spores to germinate prematurely, killing them because they cannot survive outside of their hosts’ cells. Another smaller molecule in the bee’s semen could quickly kill the fungus spores directly.

“We also found that these immune molecules in the bee semen were specifically active against the fungus but had no effect on other microorganisms,” Baer said. “This finding was surprising, because insect immune systems are often believed to be primitive and not very complex or specific.”

Baer said the spread of parasites and pathogens globally are contributing to the alarming loss of millions of bees every year. “This is problematic, given our dependence on honey bees, as they pollinate more than 80 crops of agricultural interest or about a third of what we eat,” he said.

“However this new finding, which confirms honey bees are remarkably capable of defending themselves against parasites, will provide exciting new ways to breed bees that cope with diseases by themselves. Suppressing parasites with chemicals has become a major issue because of contaminations of honey with residuals, as well as bee parasites having become more resistant against available treatments.”