The Bee Hive in Fall

The success of the colony to survive the winter is largely dependent upon the health of the bees in the fall and the beekeeper’s efforts in setting up the hive for winter. Fall is a time of transition in the bee hive. The bee colony’s population is changing from the short-lived bees of summer to the longer-lived bees that live through the winter. Bees born in the early fall are the ones that will produce the brood food for the first bees the colony rears the following year. Food stores are important. Bees must be able to sustain themselves until flowers bloom again in the spring. The bees store food of both honey and pollen in cells in the bee hive. Other necessary nutrients for the colony’s survival are stored in fat bodies in the individual bees’ abdomens. The more food that bees have available in the fall, the more nutrients they store in these fat bodies. These bees with well-filled fat bodies are best able to produce brood food for bees reared before flowers start blooming in the spring.

The health of the bees is important for the survival of the colony through the winter. If a large number of the colony’s bees are afflicted by viruses spread by parasitic mites or by Nosema disease, many bees will likely die over winter. Hives losing excessive bees often do not have enough bees to maintain a warm environment in the winter cluster. In preparing the hive in the fall, the beekeeper needs to check for the presence of bee parasites. If Varroa mite loads are high, the colony will not survive for very long. Reducing Small Hive Beetle levels to a minimum in the fall helps control these pests in the following year. The winter bee hive must also be provided with adequate ventilation to prevent the warm, moist air from condensing inside the hive and dripping water on the clustered bees. Today’s photo: Jeremy Bemis prepares hives for winter.

--Richard

Replacing Old Honeycombs

Beekeepers build hives for bees, and the bees build their nest inside the hives from beeswax, a substance that the bees produce. Young bees secrete beeswax from glands on the lower side of their abdomen. Beeswax makes a strong and lightweight nest to hold the developing bee brood as well as a storage area for bee food. The individual cells of the bee nest are used repeatedly to house bees developing from egg to larva to pupa to adult. As the bee brood changes from larva to pupa, the workers cap each cell with reused beeswax from the hive. However, workers use freshly secreted beeswax to cover the cells of ripened honey. Honey bees are attracted to the odor of old honeycombs, but old comb is a potential problem for bee health. Beeswax absorbs chemical toxins from the environment, making the hive increasingly toxic. Old honeycombs also hold the reproductive spores of a number of pathogens, namely American foulbrood, chalkbrood, and Nosema disease.

Periodically replacing old beeswax combs is a key element in Peace Bee Farm’s integrated pest management plan. Honeycomb replacement has a similar effect as changing the engine oil in a beekeeper’s truck; the impurities are removed. In today’s photo, I am using a high-pressure power washer to remove the old beeswax comb and hive materials from frames of plastic foundation. The stream of water removes pollen deposits, old bee larvae cocoons, wax moth webbing and cocoons, and small hive beetle “slime,” the waste deposits of the larvae of these hive scavengers. Once the old comb is removed from the frames, I will coat the plastic foundation with fresh beeswax, capping wax saved from harvesting honey. The bees will rapidly form this beeswax with their mouthparts into smooth sheets of comb. During a strong nectar flow, young worker bees will secrete additional beeswax to complete the honeycombs. The colonies will rear brood in clean, chemical-free beeswax cells. Providing a clean brood nest helps ensure a healthy bee colony.

--Richard

Fall Bee Hive Inspection

If a colony is queenless in the fall, it will be dead by the following spring. As beekeepers prepare their hives for winter, they need to determine which colonies stand a chance of surviving the winter. Each hive should be inspected to see if its colony has enough bees to generate heat to stay alive throughout the winter. Any hive that is extremely weak needs to be combined with a strong hive. You can usually combine a weak hive with a stronger hive by simply smoking both hives to cover the bees' scents. If you are combining two fairly strong hives, you need to separate them with a sheet of newspaper to slow the mixing of bees to keep from fighting. If each hive being combined has a queen, the weaker queen can be removed. If you don’t remove one, the queens will fight and only one will survive.

To survive the winter, the bees need to have two things: adequate hive ventilation and enough food stored in a location where the winter cluster of bees can access it. This usually means that the honey stores need to be above the brood nest. I like to rearrange the boxes so that the brood nest is at the bottom of the hive and the honey is above it. The winter cluster of bees will eat the honey above it and move up slowly throughout the winter. The cluster of bees will occupy the honeycomb emptied of stored honey. If a hive doesn’t have adequate honey stores, it is necessary to feed the bees. Fumagillin added to the sugar syrup feed helps control Nosema disease. Ventilation at the top of the hive prevents condensation and moisture build-up. Today’s photo: Judith Rutschman and Richard Underhill. Judith hosts the Memphis television program, Nature of Conservation. Judith interviewed me on the air about honey bee health matters, the effect of chemicals in the environment on bees, and the role of bees in human food production.

--Richard

Nosema Studies Underway

A Minnesota beekeeper asks if there are guarantees that the bees one purchases in packages are free of Nosema disease and tracheal mites. The answer is no. There are no visible ways to detect either condition. The pathogen causing Nosema and the mite involved in tracheal mite infestation are both microscopic. To be seen, bees must be dissected and the affected organs viewed under a microscope. At times, tracheal mite infestations lead to “k-wing” bees having unhooked wings and bees crawling along the ground. However, these conditions are not conclusive evidence of tracheal mites. The bees that one receives in a package may carry Nosema disease or tracheal mites, and it is possible that the person supplying the bees may not be aware of the condition. The recently identified strain of Nosema disease, Nosema ceranae, is being studied by scientists of the Managed Pollinator CAP, or Coordinated Agricultural Project. A CAP project for queen breeders, http://www.extension.org/pages/58424/laying-groundwork-for-a-sustainable-market-of-genetically-improved-queens:-the-bee-team, has been started in California. It is designed to help queen producers improve genetic diversity and select for bees that can defend themselves from parasitic mites and diseases. If this program works well, the team plans to establish similar programs in the Southeast and other queen breeding areas. The CAP project also gives an extensive report on the nature of Nosema ceranae at http://www.extension.org/pages/31234/nosema-microsporidia:-friend-foe-and-intriguing-creatures. The work of the Managed Pollinator CAP program is designed to provide feedback to queen producers to allow them to adjust their methods of controlling Nosema disease. The researchers are finding that Nosema infections increase the effect of viral infections in honey bees. The current method of detecting Nosema is by counting spores in the mid-gut of foragers.

Honey bees are working buckwheat vine today. The tough vine which covers small trees and invades row crops is a heavy producer of nectar in the summer. Buckwheat vine is also known as “ladies’ eardrops” because of the shape of the seed pods produced after the flowers are pollinated by bees.

--Richard

The New Nosema

A beekeeping friend in New England started packages of bees in April and May. While each colony had plenty of bees, one colony struggled. These bees took up less syrup than the other similar colonies. Eventually, they quit feeding on syrup altogether. The beekeeper requeened the colony to give it a queen with stronger pheromones and greater egg-laying potential. Still, the colony dwindled and died. A Mississippi beekeeper installed four packages of bees and captured a swarm in May. Each colony started to expand rapidly, and then they all became queenless. A Tennessee beekeeper says that he has plenty of bees in his hives, but they are not putting a surplus of honey in his supers. All three are frequently seen occurrences in beekeeping. It is possible that each shares one thing in common: the new strain of Nosema disease, Nosema ceranae. Unlike the original Nosema strain, N. apis, N. ceranae exhibits no symptoms in the bees. The bees lose their ability to digest food, and they may starve in the presence of plenty food. Like the New England bees, the nutritionally stressed bees quit eating. Nosema disease can lead to early supersedure of queens, a possibility with the Mississippi colonies. Perhaps the most notable effect of honey bee colonies being infected by Nosema ceranae is slow population build-up caused by the premature death of foraging worker bees. While a hive may appear to have plenty of bees, without a large population of the older bees, the foragers, very little surplus honey can be stored. This is a possible explanation for the Tennessee bees’ not storing honey. Nosema ceranae infection produces perforated honey gut linings, exposing the bees to viral infections. The combined effects of Nosema and viruses can be lethal.

Randy Oliver discusses current studies into Nosema ceranae on his website, http://scientificbeekeeping.com/nosema-ceranae-kiss-of-death-or-much-ado-about-nothing/. In time for the major summer nectar flows in the Arkansas Delta, I am spacing nine frames so the bees can extend the honeycomb.

--Richard

Investigating Nosema Disease

Nosema disease is receiving considerable attention, because it is now being seen as possibly associated with honey bee Colony Collapse Disorder. As researchers began their study of all known honey bee pathogens in their search for possible causes of the large-scale die-off of honey bee colonies that started in 2006, they discovered that a new strain of Nosema disease was present In the United States. The new strain, known as Nosema ceranae, is thought to have originated with the Asian honey bee. Our honey bees, of European origin, have carried another strain of this bee disease, Nosema apis. This microorganism, which has been reclassified several times and is very similar to a fungus, causes dysentery in honey bees. Now, surprisingly, the original strain has been largely replaced by the new strain. Nosema apis has easily identified symptoms, mainly waste streaking on the hive; Nosema ceranae shows no symptoms. Nosema apis is normally a winter time disease; Nosema ceranae affects bees throughout the year. While Nosema apis was rarely considered a serious condition, Nosema ceranae seems to be much more lethal. Honey bees affected by Nosema ceranae have a shortened lifespan. For honey producers, this results in a lesser number of foragers and reduced honey harvests. The new strain is being reported to exist along with certain viruses in collapsing honey bee colonies. Both strains can be controlled by Fumagillin, our only available treatment.

Researchers at The University of Tennessee are among those studying Nosema disease. At the recent Tennessee Beekeepers Association’s annual conference, Dr. John Skinner and entomology graduate students Michael Wilson and Paul Rhoades demonstrated how to remove the honey bee mid-gut and examine the contents for Nosema spores. Like American foulbrood and chalkbrood, Nosema is a spore-forming pathogen. Nosema exists in both vegetative and spore-producing states. Microscopic analysis of infected honey bees often reveals millions of reproductive Nosema spores. In the photo Paul removes the mid-gut of a honey bee. Beekeeper Shirley Murphy observes in the background.

--Richard

Chemicals in the Environment

The world that you and me and the honey bees live in is being sprayed, coated, and drenched with chemicals. Agricultural fields, lawns, and golf courses are treated with chemical fertilizers, herbicides, and pesticides to produce larger crops, and greener, weed-free grass. The visible effects of this level of chemical use can be measured in more food crop yield per acre of farmland, less fuel consumed tilling the soil, crops available for conversion into alcohol for fuel, and greener lawns and golf courses. Some of the less visible effects of today’s chemical use include weeds becoming resistant to herbicides; pests becoming resistant to insecticides, miticides, and other pesticides; water quality affected by chemical run-offs; soil damaged by persistent chemicals; increased monoculture farming; the loss of pollinator forage and habitat; and the compromising of honey bee immune systems.

While the recent report of one scientific study of honey bee health pointed to a lethal combination of Nosema disease and Invertebrate Iridescent Virus, beekeepers who have been following the CCD investigation are asking questions about the findings. Particularly troubling to some is the lack of mention of certain insecticides that have been suspected of damaging the honey bees’ immune systems. Many beekeepers in Europe and North America feel that the neonicotinoids, like Imidacloprid, have not been proven to be safe for honey bees. To add to the lack of trust among beekeepers, some are questioning the conflict of interest between researchers and chemical companies. For example, see http://money.cnn.com/2010/10/08/news/honey_bees_ny_times.fortune/index.htm. Regardless, any scientific investigation must be able to stand up to scrutiny. Confidence in tests is built by repeating the tests and increasing the number of samples taken. The association between Nosema disease and IIV Virus in collapsing honey bee colonies needs further study. The connection between sub-lethal exposure levels of Imidacloprid and honey bees’ immune systems certainly needs independent study. Today’s photo: An aerial applicator sprays insecticides to kill soybean loopers. Insecticides and fungicides are questioned as having weakened honey bees.

--Richard

CCD and Natural Selection

This week’s publication of findings in the study of Colony Collapse Disorder provides beekeepers encouragement that we are closer to having an understanding of the pathogens that are associated with the disorder. With this knowledge, we now want to know if CCD will become a controllable disorder, like so many of the conditions that beekeepers regularly face in managing their colonies. Beekeepers want to know what things they need to do to help maintain healthy colonies. It is remarkable how resilient the honey bee has proven to be. It has survived for millions of years under changing environments and in the presence of myriad pests and pathogens. This survival illustrates the strength and importance of natural selection. Only those honey bees that held the traits that allowed their survival and reproduction in the face of current environmental conditions were able to pass along their genes to another generation. Often for the survivor it is the chance result of being in the right place with the right trait at the right time. The trait may be a natural resistance to a particular pathogen.

CCD has taken a large toll on honey bees. Annual losses of colonies in North America are one in three. Recent years have found a number of pests and pathogens entering the US, most brought in unintentionally through expanding world trade: tracheal mites, Varroa mites, small hive beetles, Nosema ceranae, and a number of viruses. This week’s CCD report also listed two viruses, previously unknown, as now existing in the US. How will beekeepers adjust their hive management with the new understanding of a relationship between Nosema and Invertebrate Iridescent Virus? The larger question is: Will a line of survivor honey bees emerge that are resistant to CCD? There is reason to believe so. When tracheal mites arrived in the US in 1984 they decimated colonies. Now after a few hundred brood cycles, the parasite is much less lethal. Today’s photo: native leaf-cutting bee on perennial sunflower.

--Richard

CCD: What Now?

Well, we finally have a published report of the current findings in the study of the causes of Colony Collapse Disorder. The report is available online at http://www.plosone.org/article/info:doi/10.1371/journal.pone.0013181. I gave it a quick reading; I’ll give it a much more thorough view. The CCD study is definitely not over. We don’t necessarily know the cause, but a strong association between the collapsed honey bee colonies and two pathogens has been established. In the near future we will be hearing much about strains of DNA Invertebrate Iridescent Viruses. We will speak freely about IIV. Nosema disease will be brought further to the front of discussion. Nosema apis was around throughout beekeeping, but it was usually considered an easily controlled over-winter ailment. Nosema ceranae was only discovered to exist in the US after the CCD investigation opened up a search into all possible pathogens affecting honey bees. It was revealed that the new strain of Nosema was not only in the US before the 2006 CCD outbreak, it had replaced the original strain in many cases.

Many questions remain unanswered. What is the involvement of the numerous viruses that infect honey bees? Do environmental chemicals and pesticides play a role in CCD? How do problems associated with poor nutrition and other stressors affect CCD? How are honey bees’ immune systems affected by the recently identified IIV Virus and Nosema combination? Can we rule out any of the items that have been suspected as being involved in CCD? Further studies involving greater numbers of samples will increase our knowledge of this complex honey bee health disorder. Meanwhile, we need to thank all who worked to get us to this level of understanding. The professional researchers adhered to disciplines to ensure the validity of their studies. Beekeepers gathered samples of honey bees and comb to provide a measure of parasitic Varroa mites, pathogens, and honeycomb chemicals. The media effectively kept the story in the public’s forefront. Today’s photo: honey bee pollination’s gift, Washington peppers.

--Richard

World Trade

It is a reality that goods are shipped regularly around the world. Among the goods traded are agricultural products that are grown where the conditions are favorable and then transported to distant lands. The goods are often transported in shipping containers that can be passed from one carrier to another without unloading the contents. The containers are carried across the oceans in ships that arrive in deep-water ports. The same containers can be transferred to railroad cars or trucks for transport to terminals where the goods can be distributed to stores, markets, or processors of foods. The process efficiently moves goods around the world; however, it sometimes moves unwanted pests and pathogens as well. A number of foreign insects, mites, and pathogens have entered the United States in recent years, often as a result of world trade. Two species of deadly parasitic mites were detected in the mid-1980s. Their arrival started the rapid decline in both managed and feral colonies of honey bees. Varroa mites are responsible for vectoring at least 15 viruses that weaken and kill honey bees. Africanized honey bees have been traced to deep-water ports in the South-east. As researchers began looking for causes of the greatest die-off of honey bees, named Colony Collapse Disorder, they found a new strain of Nosema disease, Nosema ceranae, had entered the United States. This strain is a spore-forming pathogen of the Asian honey bee. Small hive beetles, bee hive scavengers from Africa whose larvae destroy honeycomb and drive honey bees from their nest, entered this country about 1999 and spread rapidly across the country. Their spread was aided by transportation of honey bee hives for pollination service.

While world trade has the potential for the accidental spreading of agricultural pests, pathogens, and invasive species, it also brings beekeepers of the world closer through the exchange of ideas and experience in treating honey bee problems. Today’s photo shows one of the shipping containers that pass Peace Bee Farm daily.

--Richard

A New Nosema

Along with chemicals found in the honeycomb and honey bee viruses, Nosema disease appears to be a contributing factor in the large-scale die-off of honey bees that has been occurring since the spring of 2007. Extensive studies of the bees are being undertaken to look at any possible sources of this die-off which is being called Colony Collapse Disorder. Nosema apis is a fungal infection found anywhere in the world that our honeybees of European descent are managed. Nosema is a spore-forming microbe that causes dysentery in honey bees. Honey bees don’t defecate inside the hive, and dysentery occurs when infected colonies are confined to the hive unable to make cleansing flights during extended periods of cold weather. Bees with dysentery leave feces on the outside of the hive. Nosema disease occurs in adult bees and is readily spread as bees consume the spores while cleaning out infected hive cells or by sharing food. Nosema apis is generally only a problem in regions with extremely cold winters. In the southern United States and throughout the tropics, Nosema disease is rarely a problem

Researchers studying honey bee health found that Nosema apis has been largely replaced by a more virulent strain of the disease, Nosema ceranae. This replacement of diseases is itself an unusual occurrence. Nosema ceranae is a disease of the Asian honey bee, a different species from our European honey bee. While the original Nosema was known as a rarely deadly, winter-time condition, the new strain is an around-the-year disease that is suspected as being associated with Colony Collapse Disorder. Fortunately, for the beekeeper there is good news; Nosema can be controlled by feeding sugar water treated with Fumagillin in either the fall or early spring. Placing bee hives facing the south where the sun warms the hive entrance encourages flying. Considerable advantage in fighting Nosema disease can be gained by regularly changing out old honeycomb, thus removing the disease-causing spores. Today’s photo shows hive-top feeders in use.
--Richard