Honey bees face multiple stressors, but IU researchers hope findings reduce colony declines

Indiana University researchers identified a microbe that may help protect honey bees against poor nutrition, which can worsen stresses that cause declining populations.

The team of researchers published findings that show the microbe, Bombella apis, is the only bacteria to withstand the diet of growing honey bees and can also synthesize all the essential amino acids needed for a healthy bee.

Adult honey bees with poor nutrition during growth stages were smaller and did not live as long, the report shows.

The new findings are important because honey bees help pollinate food crops, and beekeepers across the country have reported losing about 40% of their colonies between 2015 and 2016, the report says. This loss can threaten the multi-billion-dollar agriculture industry.

Lead author, Audrey Parish, said shorter lives mean fewer foraging flights. This puts the entire colony in a cycle of poor nutrition as less foraging will lead to pollen-starved larva and eventually colony collapse.

“One stress always noted in colonies is poor nutrition,” Parish said. “That feedback loop can pretty quickly crash a colony, so the implication is pretty dire for not having the right nutrition as larva.”

Each honey bee colony builds its entire environment, from the hive to the meticulously placed individual cells. The bees pack nectars and pollens and ferment foods within the colony, and it’s all associated with specific microbes, Parish said.

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Most of those microbes don’t survive in royal jelly — food fed to growing queens, but also given to all larvae for the first few days. Bombella apis, however, is one of the main microbes found in the biological community of queens. The microbe is also associated with honey bee larvae as it’s found in the colony’s food supply and in the “social stomach” where honey bees keep nectar.

The IU researchers began investigating Bombella apis because it’s so prevalent in the hive, Irene Newton said. Newton is a biology professor and principal investigator at the Newton Lab who helped author the paper.

The microbe makes a potent anti-fungal, Newton said, which protects developing larvae from fungal pathogens.

Good nutrition gives honey bees a better chance of surviving when faced with pathogens and parasites, Newton said. Poor nutrition means honey bees could succumb to almost anything.

“This research tells us there is a natural microbe to leverage to try and bolster and help them overcome the challenges they face,” Newton said.

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Colonies foraging in a large monoculture setting, such as a large corn or soy bean field, is akin to humans eating only white bread every day, Parish said. It’s not a nutritionally balanced diet.

Bombella apis can help fill that nutritional gap by transforming nonessential amino acids into the essential amino acids bees need to grow healthy, notably one called lysine.

In the lab, bees with poor nutrition were reported to drop as much as 50% their mass on the extreme end, Newton said.

Bees go through age-based jobs within the hive. Starting out as nurses and guards and eventually becoming foragers. Bees with poor nutrition may not make it to that final and important stage of finding food for the colony.

The final life stage is a huge physiological burden, Parish said. The bees communicate through a waggle dance to tell others where nutritious food can be found and how far away it is. Without proper nutrition in the early stages of life, this final and vital stage is imperiled.

While beekeepers may introduce lysine to hives with supplements, it is not a permanent solution. Bombella apis, however, produces lysine on its own and a supplement containing the right strain of the microbe could provide a colony with the proper nutrition through the life of the hive.

“You can give 50 grams of lysine (to a colony) and then it’s gone,” Newton said. “If you provide an organism that makes (lysine), it keeps on giving. It’s like taking vitamin versus having a microbe that can make it for you.”

The number one resource for beekeepers is time, Parish said, and any intervention that requires a lot of time is not viable.

“One thing that’s great about Bombella apis supplements is you can just put it in sugar water,” Parish said. “It gives a carb boost and is easy to lay out.”

The microbe can stay in sugar water between 36-48 hours and bees are pretty efficient at taking up water, so a colony would be likely to collect the strain of Bombella in the supplement,” Parish said.

In the future, Parish said small microbiology businesses may be able to identify and grow the correct strains of Bombella and create a dry ingredient that gets added to water.

In the meantime, non-beekeepers can help the honey bee population with a few simple actions, Parish and Newton said.

• Avoid using certain weed and pest killers that may be harmful to pollinators.

• Leave out little water sources for honey bees

• Plant for pollinators as much as you can using diverse, native plants.

Karl Schneider is an IndyStar environment reporter. You can reach him at karl.schneider@indystar.com. Follow him on Twitter @karlstartswithk

IndyStar's environmental reporting project is made possible through the generous support of the nonprofit Nina Mason Pulliam Charitable Trust.

This article originally appeared on Indianapolis Star: Honey bees are under stress and IU researchers may be able to help