The extreme heat makes bees ejaculate until they die: they expel the endophalus in an “explosive” way
Sci-Tech

The extreme heat makes bees ejaculate until they die: they expel the endophalus in an “explosive” way

A survey conducted in Canada has shown that male bees exposed to heat stress have convulsions and expel the endophallus to death.

Alison McAfee

Males of honey bees (Apis mellifera) exposed to extreme heat die horribly, ejaculating and expelling the huge endophalus, the size of the entire abdomen. To the untrained eye, the dead insects may appear to have “exploded”, but in reality it is a reaction to heat stress. At 42 ° C, about 50 percent of drones – as male bees are called – in a colony lose their lives within six hours. It is a very serious problem for biodiversity, given that these precious insects play a fundamental role in maintaining the ecological balance and in pollination, both of wild plants and of those of commercial interest. Suffice it to say that in Canada alone the economic contribution linked to honey bees is between 4 and 5.5 billion dollars a year.

Emily Huxter

The atrocious death of male bees was described by Alison McAfee, an expert on these hymenoptera at the University of British Columbia (Canada). While studying ‘queens bees’, she received images of numerous dead drones from an Armstrong beekeeper, sent to the heart of the devastating heat dome that struck North America between June and July 2021. It is estimated that over a billion marine animals were literally cooked alive in the sweltering temperatures (reaching 46.6 ° C in a village, an all-time record for Canada), while many small birds had to jump from their nests in order not to die from. overheating. Insects have also been killed, as Emily Huxter’s dramatic images show. Professor McAfee immediately got in touch with other British Columbia beekeepers and found that the drones were dying en masse from heat stress.

Emily Huxter

“When drones die of shock, they ejaculate spontaneously,” the scientist said in a press release. “They have this elaborate endophallus that protrudes and is about the size of their own abdomen. It’s pretty extreme, ”the entomologist added. Researchers know that hives are able to maintain a stable internal temperature of around 35 ° C, however when extreme heat waves occur, the temperature can rise significantly, resulting in the death of bees.

To try to ward off this deadly increase, Professor McAfee and Mrs Huxter tested a polystyrene insulation system (a kind of roof) on several colonies, noting that it was able to reduce the internal temperature by 3.75 ° C compared to untreated hives. A sugar water dispenser was also tested, which enticed the bees to return more often and to spread the water in the hive by waving it with their wings. It is a proven cooling system among hymenoptera insects. In this case the reduction was 1.1 ° C. Both systems could help beekeepers prevent the loss of numerous drones during extreme heat waves.