Some Positive Buzz about Honey Bee Numbers

AGWEB    By Alison Wedig    September 22, 2017

Honey bee numbers show a slight improvement this year over the same time in 2016, according to USDA. © Charlene FinckThe U.S. Department of Agriculture (USDA) released a positive report on honey bee colonies this past spring. The number of commercial U.S. honey bee colonies was 2.89 million as of April 1--3% more colonies than during the same time frame in 2016. The total number of honey bee colonies lost was also lower in 2017. The number of colonies lost from April through June 2017 was 226,000 colonies, or 8%, compared to 330,000 colonies lost, or 12%, in 2016.

These are positive signs that honey bee numbers are stabilizing, but the much-needed pollinators aren’t out of the woods yet.

“It is hard to look at the colony numbers and get a clear snapshot on overall bee health; what the numbers and charts don’t show is how much harder the beekeepers are working to keep those bees alive,” says Jeff Harris, Mississippi State University Extension research apiculturist and honey bee expert.

The USDA’s research shows that varroa mites were the No. 1 stressor for operations in 2017, though their impact on the colonies is down 11% this year compared to April through June 2016. While mites may be causing less harm than in the past, honey bee colonies will always face threats from this serious pest and numerous other pressures.

“Bee health has been devastated for the last 30 years not only because the varroa mite was introduced, but because other diseases and pests were introduced including the tracheal mite, Nosema ceranae (a fungal disease) and the small hive beetle. Beekeepers must continually manage these diseases and pests to keep bees healthy,” Harris says.

To address disease and pest challenges, Bayer CropScience and other agricultural companies are doing research on bee health and working to create technologies that can help beekeepers on a daily basis. Relationships between manufacturers and beekeepers are vital to keeping lines of communication open, so the two parties can work together to address issues that impact bee health.

“We are making steady progress in our collective efforts to improve honey bee health; however, there remains much work to do to achieve a truly sustainable bee industry,” says Dick Rogers, Bayer North American Bee Care Program, principal scientist and beekeeper. Rogers continues, “Beekeeping has never been easy, but the introduction of this parasite (varroa mite) has forever changed the rules of the game, forcing beekeepers to cope with this formidable foe or face the loss of their livelihood altogether.”

To combat these issues Bayer has created a number of platforms to aid in the research of new products, as well as set a goal to help feed bees by planting forages in all 50 states. (https://www.cropscience.bayer.us/news/blog/2017/june/06202017-not-out-of-the-woods-but-on-the-right)

Lastly, it is also important to understand the relationship between farmers and beekeepers. Honey bees are a critical component to agricultural production through their pollination activities.  In 2010 research from Nick Calderone at Cornell University documented that managed honey bees hired by U.S. crop growers to pollinate crops contributed over $19 billion per year to U.S. agriculture.

Taking advantage of these symbiotic relationships that farmers and beekeepers share are important for securing future benefits for all of agriculture.

“This relationship was first noticed when varroa mites first came to the U.S. There were devastating losses of bee colonies that led to shortages in those needed for pollination.” Mississippi State’s Harris says. “Some crop failures that resulted caused people to see that honey bees are important and need to be a reliable pollination source for certain crops.”  

When bees are brought into agricultural environments, the bees risk exposure to pesticides that can kill or otherwise harm them.  Of course, Harris adds, farmers need these pesticides to protect their crops from insect pests or weeds that threaten them.

“Much effort has been aimed at improving how farmers and beekeepers work together to best protect honey bees without dramatically hurting farmers who also need to make a living.  The dialogue between beekeepers and farmers must continue indefinitely if we are to get the best protection for bees while also securing the best production from the agricultural crops that need their pollination,” Harris says. 

https://www.agweb.com/article/some-positive-buzz-about-honey-bee-numbers-naa-alison-wedig/

Some Honeybee Colonies Adapt In Wake Of Deadly Mites

 Cornell University/Cornell Chronicle    By Krishna Ramanujan   August 7, 2015

A new genetics study of wild honeybees offers clues to how a population has adapted to a mite that has devastated bee colonies worldwide. The findings may aid beekeepers and bee breeders to prevent future honeybee declines.

The researchers genetically analyzed museum samples collected from wild honeybee colonies in 1977 and 2010; the bees came from Cornell University’s Arnot Forest. In comparing genomes from the two time periods, the results – published Aug. 6 in Nature Communications – show clear evidence that the wild honeybee colonies experienced a genetic bottleneck - a loss of genetic diversity - when theVarroa destructor mites killed most of the honeybee colonies. But some colonies survived, allowing the population to rebound.

“The study is a unique and powerful contribution to understanding how honeybees have been impacted by the introduction of Varroa destructor, and how, if left alone, they can evolve resistance to this deadly parasite,” said Thomas Seeley, the Horace White Professor in Biology at Cornell and the paper’s senior author. Sasha Mikheyev ’00, an assistant professor of ecology and evolution at Okinawa Institute of Science and Technology (OIST) in Japan, is the paper’s first author.

“The paper is also a clear demonstration of the importance of museum collections, in this case the Cornell University Insect Collection, and the importance of wild places, such as Cornell’s Arnot Forest,” Seeley added.

In the 1970s, Seeley surveyed the population of wild colonies of honeybees (Apis mellifera) in Arnot Forest, and found 2.5 colonies per square mile. By the early 1990s, V. destructor mites had spread across the U.S. to New York state and were devastating bee colonies. The mites infest nursery cells in honeybee nests and feed on developing bees while also transferring virulent viruses.

A 2002 survey of Arnot Forest by Seeley revealed the same abundance of bee colonies as in the late 1970s, suggesting that either new colonies from beekeepers' hives had repopulated the area, or that the existing population had undergone strong natural selection and came out with good resistance.

By 2010, advances in DNA technology, used previously to stitch together fragmented DNA from Neanderthal samples, gave Mikheyev, Seeley and colleagues the tools for whole-genome sequencing and comparing museum and modern specimens.

The results revealed a huge loss in diversity of mitochondrial genes, which are passed from one generation to the next only through the female lineage. This shows that the wild population of honeybees experienced a genetic bottleneck. Such bottlenecks arise when few individuals reproduce, reducing the gene pool. “Maybe only four or five queens survived and repopulated the forest,” Seeley said.

At the same time, the surviving bees show high genetic diversity in their nuclear genes, passed on by dying colonies that still managed to produce male bees. The nuclear DNA showed widespread genetic changes, a signature of adaptation. “Even when a colony is not doing well, it can still produce a batch of males, so nuclear genes were not lost,” Seeley said.

The data also show a lack of genes coming from outside populations, such as beekeepers' bees.

The surviving bees evolved to be smaller, suggesting these bees might require less time to develop. Since the mites infest nursery cells in hives, the shorter development time may allow young bees to develop into adulthood before the mites can finish their development. Mite-resistant honeybees in Africa are also small and have short development times, Seeley said.

Next, the researchers will study which genes and traits confer resistance to Varroa mites. The findings may help beekeepers to avoid pesticides for controlling mites and to trust the process of natural selection, and bee breeders to develop bees with the traits that have enabled bees to survive in the wild.

The study was funded by the OIST and the North American Pollinator Protection Campaign.

Read at: http://www.news.cornell.edu/stories/2015/08/some-honeybee-colonies-adapt-wake-deadly-mites

The Bee Solution to Winter

The New York Times - Environment   By C. Claiborne Ray   January 26, 2015

Q. Do bees hibernate, especially where temperatures are below freezing for extended periods? Why don’t they just freeze?

A. Many bees hibernate, though some, including honeybees, do not, said Scott McArt, a research scientist in the department of entomology at the Cornell University College of Agriculture and Life Sciences.

“Most bee species in northern climates overwinter in dormant stages,” Dr. McArt said. “For example, queen bumblebees will mate in the fall, then crawl into a crevice and overwinter alone, protected from the elements.”

The queens emerge in spring and found new colonies, which are productive through the summer, Dr. McArt said. Then, in the fall, new queens are produced by the colony to find a mate and continue the cycle.

“Honeybees are different,” Dr. McArt said. “The major reason they produce so much honey is so the entire colony can survive through the winter by feeding on it.”

The colony forms itself into a tightly packed ball, he said, “shivering” to produce heat and using the honey for fuel.

“The bees on the outside of the cluster act as insulators,” he said, “while the innermost bees generate the heat. They continually rotate their position, alternating roles as heat producer and recipient.”

Read at... http://www.nytimes.com/2015/01/27/science/earth/27qna.html?emc=edit_tnt_20150126&nlid=46934151&tntemail0=y&_r=0

Worker Bees 'Know' When to Invest in Their Reproductive Future

Science Daily    Source: Springer Science + Business Media    August 20, 2014

When a colony of honeybees grows to about 4,000 members, it triggers an important first stage in its reproductive cycle: the building of a special type of comb used for rearing male reproductive, called drones. A team of experts from the Department of Neurobiology and Behaviour at Cornell University, led by Michael Smith, studied what starts the reproductive cycle of honeybee colonies. The results are published in Springer's journal Naturwissenschaften -- The Science of Nature. 

Reproduction isn't always a honeybee colony's top priority. Early in a colony's development, its primary focus is on survival and growth. When the colony reaches a certain stage, its workers start investing in reproduction. The first step in this whole reproductive process is building cells of drone comb, the special comb made of large cells in which drones are reared.

Drones are male honeybees that develop from unfertilized eggs. Their sole purpose in a colony is to mate with virgin queens from other colonies, thereby spreading the genes of the colony that produced the successful drones. Virgin queens in turn need to mate with drones before they can lay fertilized eggs that will become workers. Queens will mate with over a dozen drones during their single nuptial flight, after which they are stocked with sperm for life.

Smith and his team were puzzled about precisely which colony features kick-start this key process of building drone comb. Is it the number of workers in the colony? Is it the total area of worker comb in the colony? Is it the amount of brood in the colony? Or perhaps it's the size of the colony's honey stores? The Cornell University researchers therefore set out to carefully manipulate each of these features in different groups of colonies, while keeping the other colony features identical.

They found that while every colony built worker comb (non-reproductive comb), not every colony built drone comb (reproductive comb). In fact, only an increase in the number of workers stimulated the workers to start constructing drone comb. This was seen whenever colonies contained 4,000 or more worker bees.

The researchers were still left wondering about precisely how an individual worker bee 'knows' how many other workers there are in its colony. Smith and his team speculate that this might have to do with how crowded individuals feel while working side-by-side in the hive. They are currently engaged in further research to shed more light on this mystery.

"Colonies with more workers built a greater proportion of drone comb, but colonies with more comb, more brood, or more honey stores, did not do so," Smith summarizes. "We estimate that a colony needs approximately 4,000 workers to invest in building drone comb."

The researchers believe that their findings are also relevant to other social systems in which a group's members must adjust their behaviour in relationship to the group's size.

Journal Reference: Michael L. Smith, Madeleine M. Ostwald, J. Carter Loftus, Thomas D. Seeley. A critical number of workers in a honeybee colony triggers investment in reproductionNaturwissenschaften, 2014; DOI: 10.1007/s00114-014-1215-x

Read at... http://www.sciencedaily.com/releases/2014/08/140820091609.htm