Honeybee decline a threat to global food supply, ASU researchers seek answers
Since the 1940s, the population has diminished from 6 million to 2.5 million hives today.
In spring, about 800,000 acres of California almond trees look to honeybees for help. Almond growers require the pollination services of two beehives per acre to produce their crop, and this time of year the state needs about 1.6 million beehives to get the job done. To reach this number, more than 1 million hives are trucked into California’s almond country annually — a practice some honeybee experts jokingly refer to as “bees on wheels.”
Honeybees aren’t merely needed to fuel the almond industry. They are critical to the entire global food supply. U.S. government reports link pollinator insects, like honeybees, to 35 percent of the world’s food production. In fact, 87 of the top 115 food crops grown in the U.S. require insect pollination. The nation’s “worker” honeybees, however, are in decline. Since the 1940s, the population has diminished from 6 million to 2.5 million hives today.
In Arizona, ASU scientists tackle honeybee population concerns from different angles and are now looking at several unique strategies that could help reverse this disturbing decline.
Colony collapse disorder
Colony collapse disorder (CCD), where a pathogen spreads within a hive and kills the colony, plagues honeybee populations. Scientists pinpoint diseases and specific contaminants, in particular pesticides, as the potential problem. When bees are at work, foraging and pollinating, they are exposed to what Jon Harrison, a professor in ASU’s School of Life Sciences, calls “an epidemiological nightmare.” They routinely encounter harmful herbicides, fungicides and other pest-repelling chemicals.
Fungicides have been a particular concern, Harrison adds. Under a recently awarded United States Department of Agriculture (USDA) grant, Harrison will partner with Brian Smith, an ASU animal behavioral neuroscientist who holds a Trustee of ASU Professorship; Jennifer Fewell, an ASU insect researcher and President’s Professor; Osman Kaftanoglu, an ASU apiculturalist; and Gloria DeGrandi-Hoffman, research leader of the U.S. Department of Agriculture Agricultural Research Service Carl Hayden Bee Research Center in Tucson; to study the effects two widely used fungicides, boscalid and pyraclostrobin, have on bees. Preliminary research has shown that when bees are fed pollen containing these fungicides, they experience reduced appetite and have difficulty digesting protein.
“You could see this poisonous attack on mitochondria,” Harrison says of the early research.
Harrison researches bee physiology; meanwhile, Smith analyzes bee brain activity associated with odors. Smith will study the neural effects of the fungicides.
Smith often looks to other disciplines, like mathematicians, to help better predict neural activity changes when an odor or stimulus is introduced to bees. He has worked with a Swiss chemist to study bee neural response to floral odors, in particular. From that, Smith learned bees associate floral smells with sugar and are then better able to find nectar.
“It’s impressive just how smart bees are and how quickly they learn. It’s like Pavlov’s dog,” Smith says. “Within 30 minutes I can have someone new in the lab training bees.”
Better pollinators, China
In what he describes as a three-decade long fascination with honey bees, Robert Page, Foundation Chair of Life Sciences at ASU and prominent honey bee geneticist, has been studying and selecting bees who are superior pollinators.
Page has found that certain bees collect more pollen (a protein) and less nectar (a carbohydrate), and enjoy superior nutrition as a result. He has also found selectively breeding this higher-protein-consuming population can lead to healthier bee colonies.
“Good nutrition is incredibly important for bee health,” he says. “With colony collapse disorder, the trend has been to try to find the smoking gun. But it isn’t one thing.”
Page is also setting up a study with the Chinese Academy of Agricultural Sciences, which will further inform his and other researchers’ understanding of bee nutrition.
China has established an international market for “royal jelly,” a protein-rich food produced by worker bees for queen bees. This market is made possible by the Chinese selectively breeding bees who produce higher volumes of royal jelly. Page will examine the physiology and metabolic pathways of these bees.
“We’d like to learn from them (the Chinese) and implement these findings in some way,” Page adds.
ASU School of Life Sciences Professor, Gro Amdam, is pioneering research that could create first-ever bee vaccines. With the help of researchers from Finland and Norway, Amdam’s research team has come to understand the importance of a critical protein called vitellogenin in bee immunity.
Vitellogenin is a key carrier of environmental bacteria digested by queen bees when they eat royal jelly. Once the queen bee digests the “royal jelly,” she then transfers the digested bacterial pieces to her larvae, which is a way of naturally vaccinating the next generation of bees. In this process, vitellogenin acts as a shuttle for the bacterial pieces.
“As humans, we protect ourselves against devastating bacterial infections via vaccination … These vaccines … provide long-term protection because our bodies develop a physiological memory of the bacterial material in the vaccines. In contrast, everybody thought insects could not be vaccinated because insects do not have physiology that allows the immune system to have memories,” Amdam says.
Knowing now that bees can be immunized, Amdam’s team is experimenting with oral vaccines that can be efficiently taken up by vitellogenin.
“We develop vaccines with bacterial pieces that are given to queens and study the physiology that allows the vaccines to be effective,” she says.
While trying to get a better understanding of the biology of the vaccine response, her team also calculates cost and benefits of launching a large-scale vaccination program. Amdam recently received a grant to continue this research until 2021. At that time, the idea of selling or licensing a patent may be considered.
“There is still a lot of science that we want to do,” she adds.
Originally published at www.azcentral.com on February 23, 2017.