Bee Health Issues
From all the information being gathered and the scope of attention being paid to the decline in the number of honey bees available to pollinate crops, regulation or guideline changes for pesticide use should be anticipated. This is even though the U.S. Agriculture Department and U.S. Environmental Protection Agency issued a “comprehensive report on honey bee health” in May that blamed the decline in bees on “multiple factors.”
But one of those controllable factors is indiscriminate insecticide use, and the onus is being placed on ag retailers, custom applicators and farmers to use best management practices and steward crop protection products better. Additionally, anyone associated with rural America is being expected to look at improving the habitat for bees.
“There is pressure to act. There will be changes to labels on pesticides, best management practices, mitigation strategies and on and on,” said David Epstein, Ph.D., entomologist with the USDA office of Pest Management Policy. He made his comments while explaining the current situation with honey bees, the life cycle of honey bees and the history of honey bees at Bayer CropScience’s Ag Issues Forum during the winter.
He participated in the October 2012 “National Stakeholders Conference on Honey Bee Health” from which the USDA and EPA based its comprehensive report on the bee situation, which provided no answers but outlined how much more research is needed to understand why bee populations have dropped drastically starting in 2006.
A 10 percent to 15 percent overwintering loss of bees is typical for commercial bee hives, but in 2006 through 2013 the annual loss of bees has been greater than 20 percent with a high of nearly 40 percent for this year’s estimate.
Every report about bee health notes how a number of factors stress bees to the point that many perish. There are old and newly identified parasites and diseases, low genetic diversity, poor nutrition and pesticides in the environment.
Pesticide Testing Protocol
As the government agencies have suggested, “The most pressing pesticide research questions relate to determining actual pesticide exposures and effects of pesticides to bees in the field and the potential for impacts on bee health and productivity of whole honey bee colonies.”
The challenge relating to pesticide impact lies in the testing. As Epstein explained, there are tier one, tier two and tier three testing. With tier one testing, you dose the bees in the lab with the pesticide and judge the response. Tier two testing involves setting up studies to simulate real-field conditions and look at not only what is happening to the honey bee itself but the whole bee colony.
Tier three is full field studies of bees in their natural habitat. “And the researchers uniformly are telling us that designing and funding of these type of studies are major challenges,” Epstein said.
He added, “With honey bees, it doesn’t matter what happens to one bee; it’s what happens to the colony” that is of major concern.
Setting up those outdoor real-field condition tests have been the center of controversy. The main insecticides under intense scrutiny at this time are the neonicotinoid class of chemistry. Activists against pesticide use claim as many as 30 scientific studies have found a link between the neonicotinoids and decresing bee numbers, including a study by the European Food Safety Authority.
Manufacturers of neonicotinoids, which includes the major crop protection companies, have been quick to claim the studies have been conducted outside of appropriate scientific protocol and the studies delivered too high of doses of insecticide compared to real-life field situations, which circles back to Epstein’s comments about tier three testing being extremely hard to do for trustworthy results.
Without a consensus of opinion about neonicotinoid dangers, the European Commission pushed ahead with banning imidacloprid, clothianidin and thiamethoxam active ingredient insecticides as May began. It isn’t likely that such a ban will occur in the U.S., any time soon. The investment in research has picked up greatly with the major manufacturers working with scientists across the nation.
Bayer CropScience is building its Bee Care Center and has a whole bee care program for interfacing with beekeepers and researchers. Syngenta has established funding grants for research and is taking leadership roles in working with private industry. Monsanto acquired a bee research company.
The most recent target of neonicotinoids’ use is as seed treatments, and this is happening just as farmers have been widely accepting the concept of using multiple active ingredient seed treatment compounds to get crops off to a fast, healthy start.
Whole Picture Look
Epstein and Dave Westervelt, assistant chief, Bureau of Plant and Apiary Inspection for the state of Florida, who also spoke at Bayer CropScience’s Ag Issues Forum, weren’t pointing their fingers at pesticides as being the main culprit for bee deaths and colony collapse disorder, where the whole hive of bees die off.
But both of them agreed that something needs to be done to increase bee populations in the U.S. “We are seeing the need for more pollination services, but at the same time we are seeing fewer bees,” said Epstein. “We had a peak back in about 1950 of almost six million bee colonies, and we have seen a steady decline since then until the latest survey from the National Agricultural Statistics Service reported about two and one-half million hives currently out there.”
There are between 25,000 and 35,000 commercial beekeepers even though the total number of persons who maintain at least one bee hive totals between 115,000 and 125,000. Many commercial beekeepers tend to their bees in northern climates during the South’s hottest time of year. Epstein speculated that the largest beekeeping operation in the U.S. is one in the Dakotas with 90,000 colonies.
Of those two and one-half million hives, Florida currently claims 360,000 of them as being based in the state. “We actually in the last four years have gone from 900 beekeepers at 240,000 hives to 3,000 keepers and 360,000 bees,” said Westervelt. “So, CCD (colony collapse disorder) has done something. It has brought us into the limelight. We have niche pollinators included in that number (one or two hive owners), but they pollinate backyard gardens, which is very important, too.
The top four crops needing commercial pollination in order of acreage are almonds, apples, melons and alfalfa. “There are about 750,000 acres of almonds in California. That is by far the driver for pollination services in this country,” Epstein said. “We need 1.5 million colonies just to serve that industry.”
Bees Shore to Shore
Westervelt noted the need for pollinators in Florida is outweighed by the California almond growers and other nut, fruit and vegetable crop growers, but Florida definitely needs a large number of bees, too.
Florida serves as a major launch pad for commercial beekeepers to transfer their bees from the southeast to California each year. A big percentage of commercial beekeepers take their bees north during the hottest time of the year then move them to Florida to be ready for the first pollen flows starting around the first week of December, Westervelt explained.
“Most of the beekeepers who come into Florida, Louisiana and Texas are here to build their bees up to go to almond pollination,” he said. “Florida sends out about 135,000 hives of bees in about a month and a half’s time on semis (trucks) to do pollination. Those bees, most of them, will come back by March 12 and go into oranges.”
A truck of 480 hives per semi-truck hauls the bees across the country in three and a half to four days. That long haul is stressful for the bees, and the bees “need watered down” because honey bees require a lot of water, Westervelt explained.
600 Years of Research
“Honey bees have been studied more in the last six years than they have been studied in the previous 500 to 600 years,” Westervelt said. This studying has resulted in the identification of viruses, bacteria and other insects that were never previously recognized as harming bees.
“We have learned more about the lesser known such as viruses, bacteria and what role they play in the life of the bee,” he said. “We knew most of the parts about how a hive operated, but with new technologies, we’ve been able to identify over 20 different viruses that are associated with bees and found some new bacteria that existed, but we didn’t know exactly what their function was in the mid-gut and causes for CCD.”
The most commonly identified parasitic pest blamed for colony collapse is the Varroa mite. Management systems and technology to try and keep the mites in check are being researched.
Saving bees even means trying to breed stronger bees with more diverse DNA. “There are a number of laboratories that are doing breeding work,” Epstein said. “There is genetic bottlenecking. We always have selected certain bees that we use for our beekeeping. And you end up with certain people doing queen production; so, you are squeezing the genetics even more.”
Today, he said, breeding researchers are looking at a lot of different genetic improvements that can assist in the bees’ health—resistance to disease, resistance to certain pests such as the Varroa mite and tracheal mite and exhibiting better hygiene. He pointed to a University of Minnesota breeder who has bred a hygienic breed of bees that specifically does a better job of cleaning the hive of any material where bacteria or fungi might become established. Perhaps one of the most unusual breeding concepts is development of a bee that would pick Varroa mites off each other.
Drought Had Impact
This year’s high die-off of bees or colony collapse shouldn’t be too unexpected. The drought across much of the upper Midwest where bees are parked in the summer resulted in a lot of weakened bee colonies. “That was a debilitating tactic in 2012,” Epstein said.
Bees fly within a five-mile radius of the hive in general to find food sources and water, and they need water to cool their hives. Because of the drought there was less forage that was palatable and much less pollen.
The states, counties and rural landowners could be doing a better job for helping keep bees healthy, especially in a drought situation like last summer. Beekeepers talk about rights of way management for utilities, highways, etc. that are sprayed for weeds and not planted with wildflowers as being a problem for bees. Additionally, they would like to see the National Resource Conservation Service (NRCS) involved in targeted planting of forage for bees. This isn’t for wild bees because the experts point out that less than 10 percent of the bees in the nation are feral and the rest are maintained by beekeepers.
To conclude, Epstein noted that causes of colony collapse is way too complicated to jump to conclusions about one cause, pesticides, when it’s probably a combination of causes. “Our EPA has said that the European Union is basing its studies on what EPA would consider incomplete science. They (EPA) prefer we have the full science done—tier two and tier three testing—instead of just the tier one testing.”