A species of stingless bee from Costa Rica has evolved an extra tooth that can bite into flesh and its gut has more in common with a vulture than other bees, according to a new paper by scientists from the University of California, Riverside (UCR).
Bees don't usually eat meat, but scientists suspect these 'vulture bees,' which come from the Trigona family, did so in response to intense competition for nectar.
There are approximately 550 species of stingless bees worldwide and while they don't sting they have other defense mechanisms, like powerful bites or blister-causing secretions. Typically, stingless bees have 'baskets' on their hind legs that they use to collect pollen.
But when UCR researchers went to Costa Rica and set up raw chicken, or carrion, bait to observe the bees, they found the vulture bees were using those baskets to collect the meat.
A vulture bee.(Ricardo Ayala)
Despite their diet, scientists say the honey from vulture bees remains edible and sweet, because the bees store meat in special chambers that are sealed off for two weeks before they access it, and those chambers are separate from where they store honey, Jessica Maccaro, a UCR entomology doctoral student, said in a statement.
The findings are significant because these are the only known bees in the world that have evolved to use food sources that aren't produced by plants, the study's authors say, although there are some stingless bees that feed on both meat and flowers.
When comparing the gut microbiomes of stingless bees that eat only flowers, bees that eat both, and bees that only eat meat, researchers found differences, with the most extreme deviations in those that exclusively eat meat.
“The vulture bee microbiome is enriched in acid-loving bacteria, which are novel bacteria that their relatives don’t have,” UCR entomologist Quinn McFrederick said.
“These bacteria are similar to ones found in actual vultures, as well as hyenas and other carrion-feeders, presumably to help protect them from pathogens that show up on carrion.”
Next up, researchers will take a deeper dive into the physiology of vulture bees and how their microbiomes support their health.
“The weird things in the world are where a lot of interesting discoveries can be found,” McFrederick said.
“There’s a lot of insight there into the outcomes of natural selection.”