The Plight of the Honey Bee

The Plight of the Honey Bee

By Derek Brandt

Pollination is essential to agriculture, horticulture production

Since 2006, when a steady decline in honey bee population was noticed, considerable research has gone into investigating the decline, called Colony Collapse Disorder. Honey bees are essential pollinators of various plants in the agricultural system as well as of plants that provide food and shelter to wildlife, plants that control erosion, plants that add nitrogen to the soil, and many plants that add beauty and color to landscapes. Honey bees and their pollination services have taken a hit and researchers are still working to figure out why.

Marion Ellis is a professor of entomology at the University of Nebraska-Lincoln. He has been in the Department of Entomology since 1995 and works primarily with factors affecting honey bee health.

"Colony Collapse Disorder has received a lot of publicity," Ellis said. "The consensus opinion of scientists studying the problem is that there is not a single cause, but there have been a lot of factors affecting honey bee health that have cumulatively filled the cup and spilled over. The biggest being recently introduced diseases and parasites that weren't in this country 20 years ago."

Ninety-five percent of crops grown in the United States require bee pollination. Ellis said that crops like cucumbers and apples are obvious, but noted that even a glass of milk has links to bee pollination. The cattle are fed alfalfa and farmers cannot produce alfalfa seed and grow it without bee pollination.

"It's not just the obvious things," Ellis said. "Most things in our diet, if you trace them, have a link to pollination."

The mite problem

Two mite species were introduced to the U.S. in the 1980s that have contributed to the honey bees' decline in population. A tracheal mite was discovered in 1984 that clogs the breathing tubes of honey bees. In addition to feeding injury it provides a port of entry for viruses and pathogens. "For four or five years, it was a big problem," Ellis said. "It is much less of a problem today due to selection and resistance."

Again, in 1987, another type of mite was discovered- the varroa mite. These parasites are flat enough to latch on between the honey bee's abdominal segments to suck blood out of the bees, shortening their lifespan, introducing viruses and pathogens, and in high infestations, causing honey bee offspring to be born with deformities.

"It is the biggest scourge of beekeeping worldwide," Ellis said of the varroa mite. "It is a very severe parasite on honey bees. It is native to another species of honey bee that live in Asia, and it is not a severe problem on that species. But on the species we keep in this country, it is a devastating parasite."

Ellis described each mite's mouth parts as being similar to a sabre. The mite pokes holes in the bees in order to ingest the body fluids that leak out, and in the process provide an entry spot for bacteria, viruses and fungi.

"I think there is a pretty good consensus that if the varroa mite would go away, a lot of the other beekeeping problems could fix themselves," Ellis said. "It clearly is the most stressful thing affecting honey bees."

Some honey bees are building up a resistance and it takes longer for the mites to damage them. Ellis stressed, though, that without beekeeper intervention, even the resistant bees will eventually die.

Honey bees won't disappear

With recent trends showing that the honey bee population is in decline, Ellis is quick to dismiss the notion of the bees' population reaching zero. Honey bees are too valuable for their ecosystem services, and current research is providing better tools for protecting and conserving them.

"I think there are a lot of things going on today that have an impact on the honey bee, Ellis said. "Climate change, certainly. Honey bees are fine-tuned to be in cycle with the blooming plant cycle. So there are a lot of things that can affect them in our world. As far as them disappearing from the planet, I think it is safe to say that if they do, we will too."

The treatment issue

In order to combat the mites, beekeepers initially had to rely on miticides to save their colonies. According to Ellis, beekeepers had no choice. They either treated the infestations or lost their colonies. "The miticides saved colonies," Ellis said. "But they also put a stress on honey bees."

Ellis, along with colleague Blair Siegfried, a professor of entomology at UNL, looked into the potential of the pesticides on the honey bee reacting with other things that the bees encounter when foraging or away from the hive and there were some treatments found that should not be used on the bee, due to these reactions. When pesticides interfere with other treatments, it is called a synergistic interaction.

"We found that when bees are pollinating fruit orchards, and almond orchards in particular, that are treated with fungicide- sometimes during bloom- the fungicides that bees are exposed to can interact with the treatments that the beekeepers are using and cause harm where either one treatment would not be a problem. 'One plus one equals seven' is a good way to think about it."

The effect on agricultural supplies

Honey bees by nature are some of farmers' best friends. They are invaluable to crops that require pollination in order to achieve bloom. According to Ellis, the crops that bees pollinate total $18.7 billion. Nebraska agriculture is not as reliant on honey bee pollination as are other states. Though the Cornhusker State does have fruit orchards and melon crops that require pollination, some agricultural regions are much more reliant on the honey bee. California, for example, grows a lot of almonds, a crop that is heavily dependent on the honey bee.

"In some agriculture systems, like California, where they grow a lot of almonds, they have to be cross-pollinated. Without bees, they can't produce one almond. Almonds are worth six to seven thousand dollars per acre to the growers. So they're currently renting more than half of the honey bees in the United States to be moved to California in February to pollinate that crop," Ellis said.

Before 2007, Ellis noted that the main source of income for beekeepers was honey but that has since changed over to renting honey bees to pollinate the almonds blueberries, apples, cherries, cranberries and other crops. Almond acreages have expanded rapidly and have become more profitable than producing alfalfa or cotton, which were alternative crops in the central valley of California. In many areas the potential to earn pollination income exceeds the value of the honey that can be produced as growers are competing for the bees they need to make their crops profitable.

"A concern is that they are continuing to expand the almond acreage in California," said Ellis. "It requires less water than some of the other crops and is more profitable. The demand for bees is going up. If we don't come up with some good solutions that allow beekeepers to expand operations to meet that demand, it is going to impact people other than beekeepers."

The University of Nebraska-Lincoln role

UNL is providing many ways to educate people about all things honey bee. Ellis conducts workshops for new beekeepers, and the public also has responded to the news about problems with honey bees by wanting to become beekeepers themselves. "Our participation in those programs has nearly doubled in the last two years," Ellis said. "We have a number of offerings for both beginning and advanced beekeepers that we offer. The value of those is you just need to know a little more getting started to succeed with bees than you did 20 years ago before we had all these issues that have been introduced."

One class on the UNL campus includes students who start their own hives, which they'll take home at the end of the semester. As far as research is concerned, in past years, Ellis spent a lot of his efforts on researching the varroa mite problem. In the last two years, synergistic interactions with pesticides have been the course of study.

What can we do?

The public can do its part to change the direction of the honey bee's population, Ellis said. Planting flowers can help the bee population because the diversity of blooming plants provides food for the bees. The Nebraska State Arboretum has suggestions for which plants to grow for honey bees.