Researchers from the University of California have found that wild bees share bacteria with the flowers they pollinate. The study provides new insights into the microbiomes of wild bees and shows that flowers may be an important source of beneficial bacteria. The details were just published in the journal Microbial Ecology.
The microbiomes of honeybees and bumblebees have been studied extensively. However, there has been little research on the gut microbes of wild bee species. Bee research tends to focus on honeybees since they can be raised commercially and are the main pollinators for many important crops. Bee populations are dropping, however, and millions of honeybee hives have fallen prey to colony collapse disorder. If honeybee populations continue to fall, wild bees may become critical for crop pollination.
The research team established artificial bee nests in fields by drilling holes into wood. The team covered some of the wildflowers in the area with bags, picking the flowers right after they bloomed. They also collected flowers that had been visited by bees. The researchers then analyzed the bacteria present on the flowers and in the guts of the wild bees.
The bees and flowers shared a common bacteria species, a type of Lactobacillus. The bacteria were present in the guts of the bees and were also found on all of the flowers. The flowers that had been visited by bees had a greater quantity of bacteria, showing that the wild bees were transmitting the microbes. The covered flowers still had small amounts of Lactobacillus and the authors speculate that the bacteria may have arrived through the air or transmission by small insect vectors. The team is proposing the name Lactobacillus micheneri sp. nov. for the new bacteria species.
As global bee populations crash, wild bees will become more critical for their role as pollinators. Wild bees have been understudied and this study was the first to examine bacteria transmission between bees and flowers. The team believes that the identified bacteria are beneficial to wild bees but more research is needed to determine the effects of Lactobacillus and other gut microbes.
Quinn S. McFrederick et al. Flowers and Wild Megachilid Bees Share Microbes. Microbial Ecology (2016).