Stingless bees can mummify invading beetles in resin

Washington, January 4 (ANI): In a new research, scientists have found that stingless bees are not easy targets for predators, as they can mummify invading parasitic beetles in resin.

"They're stopped in their tracks and they dehydrate and shrivel up like a mummy," said Mark Greco, an entomologist at the Swiss Bee Research Centre in Bern.

According to a report in New Scientist, Greco discovered the practice in a species of Australian stingless bees, Trigona carbonaria, living in the wild.

To further investigate this peculiar defence, Greco's team planted parasitic small hive beetles, Aethina tumida, near the entrance of laboratory beehives.

Guard worker bees instantly attacked the parasites, but the thick-skinned beetles had little trouble warding them off.

Faced with such a resilient foe, a group of workers resorted to coating the beetles in a sticky mix of resin, mud and wax.

From computerised tomography (CT) scans of hives flash-frozen at 5-minute intervals, Greco's team found the mummifications take less than 10 minutes.

The beetles rarely got very far from the entrance before being mummified.

The only time Greco saw the beetle invasions succeed was during a hot Australian summer, when temperatures above 40 degree Celsius may have stressed the bee colony and prevented the resin from setting.

The behaviour may have evolved out of conventional hive-patching, in which stingless bees use a similar resin to secure loose bits of their hive.

"Their instinct is to glue something down if it's not secure," Greco said.

Other stingless bees also make mummies out of intruders. Some tropical species even mix in acidic secretions that eat away at the beetle's hard cuticle. (ANI)