The majority of bees eat pollen and nectar, but certain species have evolved to eat meat, according to a new study.
Scientists from the University of California-Riverside, Columbia University, and Cornell University analyzed the gut bacteria or microbiome of so-called vulture bees to better understand this drastic change in diet. The bees' guts are full of acid-loving bacteria similar to those found in vultures, hyenas, and other carrion-feeding animals, researchers have found.
"The vulture bee microbiome is enriched in acid-loving bacteria, which are novel bacteria that their relatives don't have," Quinn McFrederick, an assistant professor and bee specialist at UC Riverside and an author of the study, 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."
The guts of honeybees, bumblebees, and stingless bees are all populated by the same five core microorganisms, which have survived for 80 million years, according to the study. The researchers were curious about the differences between the guts of vulture bees.
Adult bees for the tests were collected in April 2019 at field stations in La Selva and Las Cruces, Costa Rica. Large slices of fresh chicken were strung from branches with string at each site's 16 "bait stations."
The researchers set up 16 stations with 50 grams (1.8 ounces) of raw chicken dangling from branches 1.5 meters (4.9 feet) above the ground as bait. They used petroleum jelly to keep ants away from the string. They collected 159 bees in total, including pollen-eating and meat-eating bees, as well as vegetarian bees that only eat pollen and nectar.
Despite having significantly smaller baskets on their hind legs than their vegetarian cousins, the vulture bees were able to use them to capture chunks of masticated chicken, according to the authors.
The researchers discovered that vulture bees had lost some of the core microbes that most bees have and evolved a more acidic gut after researching their microbiomes by extracting DNA from their abdomens.
Lactobacillus is one of the bacteria found in vulture bees, and it's also in a lot of fermented foods, like sourdough, according to a news release. They also included Carnobacterium, a bacteria linked to the digestion of meat.
Despite the fact that they eat on flesh, the honey produced by vulture bees is sweet and edible, according to the study.
Their study was released on Tuesday in the journal mBio, published by the American Society for Microbiology.