Most bees feed on pollen and nectar, but some species have become carnivores, replacing flowering meadows with animal carcasses.
To better understand this radical change in diet, scientists at California-Riverside, Columbia and Cornell Universities studied the gut flora (or microbiota) of so-called “vulture” bees in Costa Rica. The researchers found that the bees’ intestines are rich in acid-loving bacteria, similar to those found in vultures, hyenas and other animals that feed on rotting meat.
O study was published last Tuesday (23) in the academic journal mBio, edited by the American Society for Microbiology.
Only three species of bees in the world (which belong to the group of “vultures” bees) have developed in such a way as to obtain their protein exclusively from carcasses — and they only live in tropical forests. However, there are other species of bees that can consume animal carcasses when available, but they also feed on pollen and nectar, according to the research.
Bees and Intestinal Bacteria
The intestines of bees (stingless and stingless) and drones are colonized by the same five major microorganisms, and they kept these bacteria for about 80 million years, according to the study. The researchers wanted to find out how the intestines of vulture bees differ.
Scientists set up 16 posts with 50 grams of raw chicken swinging from branches 1.5 meters high. To avoid ants, they coated the ropes with petroleum jelly. So they managed to collect 159 bees in total, including, for comparison, bees that feed on pollen and meat and “vegetarian” bees that feed exclusively on pollen and nectar.
After studying the intestinal flora of the bees, extracting DNA from their abdomens, the researchers noticed that the “vulture” bees had lost some of the main microorganisms, which most bees have, and that they had developed a more acidic intestine.
“The microbiota of ‘vulture’ bees is enriched with acid-like bacteria, which are new bacteria that their ‘relatives’ don’t have,” said Quinn McFrederick, study author, assistant professor and bee expert at UC Riverside . “These bacteria are similar to those found in real vultures, as well as in hyenas and other animals that feed on carcasses, presumably to help protect themselves from pathogens found in carrion.”
He added that bees that feed on both pollen and animal carcass have different types of bacteria compared to bees that feed exclusively on pollen or exclusively on carrion. This suggests that they harbor a greater diversity of microorganisms in response to their different diet or that they are disposed to a greater diversity of microorganisms due to the fact that they have contact with both flowers and carcasses.
One of the bacteria present in “vulture” bees is Lactobacillus, present in many fermented foods consumed by humans, such as sour dough. Another bacterium found in their bodies was Carnobacterium, associated with the digestion of meat.
Although they feed on meat, the honey produced by “vulture” bees is sweet and edible, according to the researchers.
“They store the meat in special chambers (in the hives), which are isolated for two weeks until they can access them. These chambers are separate from the place where they store the honey,” says Jessica Maccaro, a doctoral student at UC Riverside who also participated in the study.
(Translated text. Read the original here).