Want your bees with more bite? As it turns out, Costa Rica is home to a more al dente species: the vulture bee. Far from the fuzzy vegetarians we have come to know and love, these insects are carnivorous and have the teeth and – as it turns out – guts to go with it.
A paper published in the journal mBio took a deep dive into these beasties' bowels. Their investigations revealed that in true vulture by name, vulture by nature style, these insects share gut microbiome constituents with the carrion-consuming birds. The adaptation reveals how it is that these bees have developed such a taste and tolerance for rotting carcasses.
The study (humorously titled “Why did the bee eat the chicken? Symbiont Gain, Loss, and Retention in the Vulture Bee Microbiome”) collected 159 bees that ate either pollen, carrion, or a bit of both, amounting to 17 species from nine genera. They were mostly collected from La Selva and Las Cruces field stations in Costa Rica using carrion and chicken as bait.
Watching the meat eaters flock to their rancid offerings, the researchers made a curious observation.
“They had little chicken baskets,” said UCR entomologist Quinn McFrederick in a statement – the vulture bees stored meat in pockets, much like how pollen-eating bees store their foraging finds.
Vulture bees are unique as they are thought to be “the only bees in the world that have evolved to use food sources not produced by plants,” said UC Riverside entomologist Doug Yanega, who says it constitutes “a pretty remarkable change in dietary habits.”
It was expected, then, that their gut microbiomes might stand out compared to those of honeybees, bumblebees, and stingless bees whose tummies all contain the same five core microbes. This has been the fashion for bees for around 80 million years of evolution. So, do our vulture bees buck the trend?
Comparing the gut microbiomes of pollen-eaters, meat-eaters, and the omnivorous, the study authors discovered that there were significant differences between the different diets.
“The vulture bee microbiome is enriched in acid-loving bacteria, which are novel bacteria that their relatives don’t have,” 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.”
And that wasn’t the only surprising difference.
“Even though they can’t sting, they’re not all defenseless, and many species are thoroughly unpleasant,” Yanega said. “They range from species that are genuinely innocuous to many that bite, to a few that produce blister-causing secretions in their jaws, causing the skin to erupt in painful sores.”
Despite their savory diet and unsavory behavior, the honey of vulture bees is reportedly still edible and actually sweet. But if Bear Grylls turning into Benedict Cumberbatch taught us anything, it's that sometimes the price is too high for a bit of honey.