Quinn McFrederick / UCR
Ask a random person to imagine a bee and they’ll likely conjure up the familiar black and yellow striped creature that hums from flower to flower collecting pollen to bring it back to the hive. But a more unusual group of bees can be found “slicing pieces of meat from carcasses in tropical rainforests,” according to the authors of a new paper published in the journal mBio. As a result, these bees have gut microbiomes that are markedly different from their fellow buzzers, with populations more common to hyenas and scavenging vultures. They are therefore commonly called “vulture bees” (or “scavenger bees”).
According to the authors – entomologists from the University of California at Riverside (UCR), the University of Massachusetts, Amherst, Columbia University and the American Museum of Natural History – most bees are basically “wasps that have switched to a vegetarian lifestyle.” “But there are two recorded examples of bumblebees feeding on carrion dating from 1758 and 1837, and some species are known to occasionally feed on carrion in addition to foraging for nectar and pollen. (They are considered” facultative scavengers. ” , as opposed to vulture bees, which are considered “obligate scavengers” because they eat only meat.)
An entomologist named Filippo Silvestri identified the first “vulture bee” in 1902 when analyzing a group of pinned specimens, although no one called it that because they did not know at the time that this species was found. fed on carrion. Silvestri nicknamed him Trigone hypogeum, and he also described their nests as being used for honey and pollen, although later researchers noted a surprising lack of pollen. On the contrary, biochemical analysis revealed the presence of secretions similar to those given to queen bees in the nests of honey bees.
Then, in 1982, entomologist David Roubik of the Smithsonian Tropical Research Institute in Panama reported surprising results from his observations of Trigone hypogeum colonies. Rather than collecting pollen from flowers, this species ingested the flesh of dead animals: lizards, monkeys, snakes, fish and birds. Bees that stumbled over a tasty piece of rotting flesh deposited a trail of pheromones to call out their nest mates, who usually converged a lot on the corpse within eight hours.
DW Roubik, 1982
Vulture bees often entered a carcass through the eyes, like maggots, and Roubik particularly emphasized how efficiently they can consume a carcass. A large lizard was reduced to a skeleton in two days, while bees took just eight hours to remove all the feathers and flesh from the head of a dead sparrow. They reduced two frogs to skeletons in six hours. Because they fed on carrion rather than collecting pollen, this species had a distinctive hind leg, with a greatly reduced pollen basket compared to “vegetarian” bees.
The bees ate the flesh on the spot, storing a sort of “meat slime” in their crops to bring it back to the hive. Roubik hypothesized that once at the hive, the bees transformed this slurry into a kind of glandular substance, which they then stored in pots of wax. “Considering that animal flesh rots and would not be suitable as stored food, its metabolic conversion is essential to enable storage,” he wrote. Another hypothesis, proposed in 1996, suggests that the actual flesh is what is stored in the wax pots.
DW Roubik, 1982
We now know of three distinct groups of vulture bees that derive their protein exclusively from carcasses: Trigone hypogeum, Trigona crassipes, and Necrophages of Trigona. They are stingless bees, but they have five large, sharp teeth and they are known to bite. Some people excrete substances with their bites that can cause painful blisters and sores.
