Tuesday, September 12, 2017

Resistance to Antibiotics

For decades, beekeepers have used antibiotics in the control of certain honey bee diseases, particularly European foulbrood and Nosema disease. While antibiotics can be effective drugs, their misuse can lead to the development of strains of disease that are resistant to the medications. Resistance has occurred as well in diseases of humans and livestock. American foulbrood, AFB, a honey bee brood bacterial infection, is often resistant to antibiotics. The use of antibiotics is not effective for controlling AFB, as they only suppress the disease-causing bacterium; they don’t kill it. To limit the use of antibiotics administered to animals, the U.S. Food & Drug Administration has recently enacted a Veterinary Food Directive. This action will greatly restrict the use of antibiotics administered to bee hives. Unfortunately, the unavailability to obtain the antibiotic, Terramycin, will likely lead to the spread of European foulbrood, the fastest spreading honey bee brood disease.

A report the Idaho Statesman, http://www.idahostatesman.com/news/nation-world/health-and-medicine/article172080432.html, describes research being conducted at the University of Idaho. Researchers are trying to determine the mechanisms of bacteria developing resistance to antibiotics. Such a resistance is a problem for treating disease anytime antibiotics are used in humans, livestock, and even in honey bee colonies. The results, published in Nature, focus on plasmids, tiny pieces of DNA that can be transferred between bacteria cells. Plasmids transfer traits, such as resistance to antibiotic drugs, from one bacterium to another. Surprisingly, this can occur in as little as a few minutes. Resistance to antibiotics also occurs when bacteria chromosomes mutate. Interestingly, plasmids can produce resistance to multiple antibiotics at once. Research team leader, Dr. Eva Top, describes how we are affecting bacteria: “They’re picking up a lot of antibiotic resistance genes and spreading them because of our habits of using so many antibiotics.” Today’s photo: migratory hives in Idaho’s Treasure Valley, an area of diverse agricultural crops. Many crops are in bloom, and honey bee colonies are collecting nectar and building up honey stores after travelling for pollination service.

Sunday, September 3, 2017

New Findings on Queen Bees

Queen bees and worker bees develop from fertilized eggs, and drone bees develop from nonfertilized eggs. Queens develop from eggs laid in downward facing queen cell cups similar to the one on the side of a top bar hive comb (photo by Melissa Bridgman). A New York Times piece, https://www.nytimes.com/2017/08/31/science/honeybees-queens.html?,  describes recently published research from PLOS Genetics identifying a newly-identified mechanism involved in the development of queen bees. It has long been known that queen bee development is associated with diet. Worker bees feed developing queen bees and worker bees a different diet even though they both develop from the same fertilized eggs. The larvae of both queens and workers are fed an enriched food, royal jelly, in the first day of larval development. Worker larvae are then fed secretions workers produce from “bee bread,” a food consisting of fermenting pollen and honey. Queen larvae, however, continue to receive royal jelly through their larval development and throughout their life.

The new research finds that caste development, the differentiation of queens, which have a complete reproductive system, from workers, that are sterile, uses plant-based small molecules called microRNA. The study’s co-author, Dr. Chen-Yu Zhang explains, “The royal jelly and plant microRNA work together to affect caste formation.” It now appears that the plant-based molecules suppress the workers’ ovary development. This research expands our understanding of queen bee caste differentiation. It also reflects the interdependence of plants and honey bees. Flowering plants and bees have been co-evolving for the past 100 million years. Plants and bees share microRNA, a plant substance that affects bee development and a bee substance that is important in the development of certain flowers. Dr. Zhang explains that microRNA from bees can make flowers larger and more colorful. The authors relate that these microRNA molecules affect species in different kingdoms, such as plants and insects or plants and humans. Other experts reacting to the report expect that microRNA will emerge as a major area of research in human medicine.

Friday, September 1, 2017

Sampling Varroa Mites

Varroa mites are the greatest pest killer of honey bees. If left unchecked, these parasites will kill a colony of bees in about 18 months. It is, therefore, necessary for beekeepers to be aware of the mite load that a hive carries and to take corrective action when mite numbers exceed critical levels. Varroa mites live in bee hives, and they reproduce in the sealed brood cells of the pupal stage of honey bee brood. Mite levels typically peak in late summer at the time that queen bees slow their rate of egg laying. Excessive numbers of Varroa mites in the hive often lead to colony death. Mites weaken individual bees by sucking the bee’s blood, known as hemolymph. When a mite pierces the exoskeleton of a honey bee, it passes numerous viruses to the bee. At least 15 Varroa-vectored viruses have been identified. Varroa mites and the viruses that they transmit lessen the life span of the bees, leading to smaller winter colony clusters. These smaller clusters are often unable to generate enough heat to survive the winter.

Some individuals ignore the threat of parasitic mites and lose their bee. Others attempt to kill the mites with harsh chemical treatments. They are usually successful in reducing the colony mite loads, however, repeated use of harsh chemicals leads to populations of mites that are resistant to the chemicals. Beekeepers who take a judicious approach to controlling parasitic mites develop their own Integrated Pest Management program that involves mite sampling and treatments as necessary. The Honey Bee Health Coalition offers Tools for Varroa Management: A Guide to Effective Varroa Sampling & Control as a free document. The guide and video demonstrations of Varroa control techniques may be downloaded from http://honeybeehealthcoalition.org/varroa/. There are several methods of sampling a bee hive’s mite levels, including powdered sugar rolls and alcohol rolls. In today’s photo, Rita is counting the number of Varroa mites on 300 bees using a simple alcohol roll test.

Thursday, August 24, 2017

The Sun's Corona

Photographer, Mike Worthy, captured this picture of the sun at total eclipse showing the sun’s corona, the atmosphere of the sun. See NASA’s website: https://eclipse2017.nasa.gov/sun. The photo was taken August 21, 2017 at Marshall County, Kentucky. Thank you, Mike!

Beekeepers Observe an Eclipse

An eclipse of the sun is a rare event. A total eclipse passed across the entire United States on August 21, 2017, the first such occurrence in nearly 100 years. Rita and I travelled to Marshall County, Kentucky to meet beekeeping friends, Shirley Murphy and Mike Worthy along the path of the moon’s totally shadowing the earth. The trip was worthwhile. The experience of observing a total eclipse is significantly different from witnessing the same event a short distance away in the much wider area of partial eclipse. The 70-mile-wide area of total coverage of the moon’s shadow affords researchers and photographers an opportunity to observe the sun’s structure in rare detail. It also provides a rare and awe-inspiring spectacle of nature for anyone in place. Mike Worthy, an accomplished photographer and amateur astronomer, photographed the eclipse. Here is Mike’s photo of the sun at total eclipse, showing solar prominences, red streams of hot gasses looping hundreds of thousands of miles out into the sun’s outer atmosphere. See NASA’s website for a description of solar prominences: https://www.nasa.gov/content/goddard/what-is-a-solar-prominence.

As the moon crossed in front of the sun, the sky slowly darkened. Within a few minutes of total eclipse the air cooled and colors shifted. August lawns turned a brighter green; Mike’s white car turned silvery gray. When the moon finally covered the sun, the sky abruptly darkened. The only light showing was an orange glow in the horizons. Planets and mosquitoes appeared. Song birds called, and crickets chirped. Beekeepers questioned how honey bees would react to light conditions darkening to nighttime at mid-day. Alert beekeeper, Brent Ferguson, along with three others in his bee yard in central Arkansas in the area of partial eclipse, watched the bee hives for any change in the bees’ behavior. There was no observed change in behavior. Did the foraging bees change their navigation from solar guidance to ultraviolet, magnetic, or odors? Eclipses are rare; honey bees are resilient and capable of operating in rapidly changing conditions.

Friday, July 28, 2017

Water for the Bee Hive

Honey bee workers forage for four things that they bring into the bee hive: nectar, pollen, propolis, and water. Nectar is the sugary secretion of flowers that bees convert into honey. Pollen, also a product of flowers, is a necessary component of bee food that contains protein, fats, vitamins, and minerals. Propolis is a sticky substance that bees gather from the saps and gums of trees. It is the “bee glue” that honey bees use to seal cracks and openings in the bee hive, and, due to its antimicrobial properties, protect the hive from pathogens. Water is an important part of the life of a honey bee colony. Bees require water for metabolic processes; they use water to dilute stored honey for consumption in the hive; and they use water to help cool the hive. Honey bees are quite adept at regulating the environment inside the bee hive. Whenever there is brood in the hive, which is most of the year, the bees regulate the hive temperature to 95 degrees Fahrenheit. Bees must cool the hive in the summer. They do this in part by fanning their wings across droplets of water. With July temperatures above 95 degrees, the bees are foraging heavily for water.

A bee hive consumes lots of water. It is important for the beekeeper to ensure a reliable source of water for all bee yards. Unless an apiary is located near a natural body of water, like a lake or stream, artificial water sources should be provided. Because scout bees share the flavor of water that they find, bees prefer water with a taste. Bees will readily forage from pet or livestock watering containers.  Bees also like to collect water from swimming pools; and, for this reason, beekeepers need to provide an attractive water source close to urban hives as part of their Good Neighbor efforts. In today’s photo, honey bees float on duckweed and water lilies in my goldfish ponds to collect water.

Wednesday, May 31, 2017

GMO Crops and Bees

New technologies are, rightfully, viewed with skepticism. One of our blog readers asks, “Is there any effect of transgenic crops on bees?” The use of genetic engineering involves transgenic material, a portion of one plant or animal, being inserted into another organism. The resulting plant or animal is described as being a “genetically modified organism,” or GMO. In the case of crops, the purpose of the transfer of genetic material is to produce a new crop with desired traits. A number of crops are regularly produced using transgenic technologies include corn, rice, soybean, cotton, and rapeseed. Some GMO crops, especially soybean, cotton, and canola (rapeseed), are regularly foraged by honey bees. Careful study continues to determine any effect that the planting of GMO crops that are food sources for honey bees will have on the health of the bees and the safety of the honey that the bees produce.

Currently, there are two principal uses of GMO technology used to produce agricultural crops. The first employs Bt (Bacillus thuringiensis) genes to produce a toxin in crop plants as a means of controlling insect pests. The second GMO technology in common usage is designed to control crop weeds. The herbicide glyphosate, known as Roundup, is in widespread use to control broad-leaf weeds and grasses. Genetically modified corn, canola, alfalfa, sugar beets, and cotton are resistant to glyphosate. The herbicide can be sprayed over the genetically modified, glyphosate-resistant crop plants and weeds, killing only the weeds. Neither Bt toxin nor glyphosate-resistant GMO technologies appear to be harmful to honey bees and other pollinators, nor do they contaminate honey. The use of glyphosate-resistant technology does have a negative effect on bees and insect pollinators when it destroys the weedy field margins that previously provided food and habitat for these insects. Today’s photo shows a GMO soybean field. Glyphosate herbicide killed the weeds and grass in the crop area and along the field margin, leaving soybean plants growing without competition.

Friday, May 19, 2017

Reversing the Bee Hive

Throughout the spring, healthy honey bee colonies rapidly increase in population. This occurs as flowering plants are making nectar and pollen significantly more abundant. Both are collected by foraging worker bees and welcomed into the hive. The pollen is stored in close proximity to the brood nest where the queen is laying eggs and the workers are feeding and tending to the developing brood. The nectar, which will be converted into honey, is stored in the hive area outside the brood nest beyond the surrounding pollen. However, if there is not enough free honeycomb cells available, the bees will store the nectar in the brood nest. When this happens, beekeepers describe the hive as being “honey bound.” A serious hive problem results because the queen is left with no place to lay eggs. Prolific queens need at least 1500 empty cells per day to lay the eqqs necessary to sustain the colony’s population. As the brood nest becomes congested with nectar and honey, the colony starts making preparations for swarming. It is important for beekeepers to check for brood nest congestion and to take corrective action.

Honey bees cluster together and generate heat during cold weather. It is common for the cluster of bees to gradually move upward in the hive over the winter months. In the spring, beekeepers need to determine the position of the brood nest and the cluster of bees. Some colonies will move back down into the lower portion of the hive during the spring, but it is common for bees to remain in the upper half of the hive. This has the effect of the bees living in a hive of one-half its normal volume. Reversing the position of the hive bodies gives the colony greater capacity in the brood nest, providing cells for the queen to lay eggs. This is an important beekeeping measure in swarm suppression. Today’s photo: a queen bee on a honey-bound frame with capped honey, liquid honey, and pupa-stage brood.

Saturday, May 6, 2017

Swarm Season

Healthy honey bee colonies swarm. Swarming is the honey bee’s way of reproducing on a colony-wide basis. Honey bees typically swarm in the spring, and this season has been exceptionally “swarmy.” The Mid-South experienced a warm winter, and springtime weather arrived early. Warm weather and frequent rains brought plenty of wildflowers into bloom. Mild weather allowed the bees to take advantage of red maple and other early-blooming plants. Early-season pollen flows stimulated the queens to rapidly increase egg-laying in late winter and spring. Unless beekeepers expand the capacity of their hives in the spring by rearranging hive bodies and adding extra boxes of frames, hives tend to get congested with honey. Brood nest congestion, where the queen doesn’t have adequate numbers of cells to lay eggs, leads to swarming.

Beekeepers don’t like for their hives to swarm. The smaller resulting colonies don’t have enough bees to produce a surplus of honey. The effect of a hive’s swarming is that this year’s honey crop just flew away! However, beekeepers are often able to capture swarms of bees where they rest, often on a tree limb or structure like the wall of a house, before they fly away to a permanent nesting location. These captured bee colonies make for good replacements of winter hive losses. Captured swarms are particularly useful because the bees are especially capable of drawing out beeswax honeycombs. If the beekeeper feeds sugar syrup to a newly hived swarm, it will rapidly fill the hive with honeycombs. Captured bee swarms are a source of genetic diversity, and they may bring in desirable traits. Beekeepers should evaluate their swarm colonies and replace the queen if the bees show undesirable traits, such as excessive defensiveness. Today’s photo: young workers make orientation flights at the entrance to a hive of swarming bees captured in early April. Swarm catching can be quite exciting. A beekeeping friend, an avid outdoorsman, proclaims that he would rather catch a swarm of bees than a five-pound bass!

Tuesday, February 21, 2017

Mid-Winter Hive Check

Whenever the winter weather conditions are suitable, beekeepers examine their hives. An extremely mild Mid-South winter brought several warm days with temperatures rising above 50 degrees, allowing bees to fly from their hives and beekeepers to check them. If the temperature is barely above 50 and conditions are windy, one can only open the hives briefly. Extensive exposure can chill and kill brood. If somewhat warmer conditions exist, a more in-depth examination of hives is possible. We experienced several suitable beekeeping days in February. Any hive check involves looking for evidence of an egg-laying queen, ample stores of food, and signs of bee disease. A mid-winter check of hives revealed colonies with rapidly expanding populations. Queens were laying eggs in all hives; and while warm weather allowed the bees to fly and consume lots of honey, all of the hives held adequate food stores.

Hives with lesser populations of bees require particular attention. Examining one weak hive revealed a small population with no worker brood. I found the queen shown in today’s photo surrounded by a retinue of attendant workers constantly stroking her abdomen. However, the queen was damaged; her wings were incomplete. The queen appeared to be afflicted with Deformed Wing Virus, one of more than a dozen viral diseases commonly vectored by parasitic Varroa mites. A queen with deformed wings would have been unable to make her mating flights as a young adult. An unmated queen cannot lay the fertilized eggs needed to produce worker bees or queens. Without these bees, the colony is doomed to collapse. This deformed queen evidently emerged the previous fall. The workers in the hive were long-lived bees produced by this queen’s mother. Deformed Wing Virus affects drones and workers more frequently than queens. It is likely that a female Varroa mite entered the queen cell before it was capped, and then the parasitic mite transferred the virus to the developing queen pupa. Varroa-vectored viral diseases cause the loss of many honey bee colonies.

Saturday, January 28, 2017

Pollen Bees

Our managed hives are home to honey bees, but some people think that these industrious creatures should be called “pollen bees.” Of course, honey bees produce honey; but they also spend their lives deeply involved in handling pollen. While bees are collecting pollen from flowers and bringing it back to their hive for food, they are also moving pollen among flowers. Pollen is the male reproductive cells of flowering plants. As honey bees fly, their bodies pick up an electrostatic charge. When the foraging workers encounter flowers, fine grains of pollen adhere to their hairy bodies. As bees move around within a flower and as they move from flower to flower, they unknowingly transfer grains of pollen to the sticky female flower organs, the stamens. This begins the reproduction of the flowering plant. Pollen that the bees carry to the hive provides protein, fats, vitamins, and minerals for the bees’ diet. Once pollen has been combined with honey, a carbohydrate, the bees have a complete diet. The mixture of pollen and honey ferments with microorganisms supplied by the bees to become “bee bread,” the source of bee brood food.

Arkansas’s warm weather in January allowed bees to leave their hives to forage for pollen. Several central Arkansas beekeepers noticed bees returning to the hives with green-colored pollen. Pollen occurs in colors from white to black. Much is yellow or orange in color. Dandelion, like the wildflower being foraged for pollen in today’s photo, is the first reliable source of pollen in mid-winter. Skunk cabbage, a plant that sometimes sprouts through snow-covered ground, is another plant to bloom early in the year. The availability of foraged pollen stimulates the queens to lay eggs. Since queens resumed their egg laying on the winter solstice, December 21, many hives now have considerable brood to feed and protect from chilling. Make sure that your bees have plenty of stored honey. There’s still a long time before nectar and pollen are abundant in April.

Wednesday, January 4, 2017

Bee Stings

First, honey bees are stinging insects. They have stingers, and their sting is painful. However, honey bees are relatively gentle creatures, and they only sting to protect their hive. The craft of beekeeping involves employing techniques passed down over hundreds, even thousands, of years for handling bees. For example, we know from cave paintings that people have used smoke in ancient times to help control the behavior of bees when we “rob” them of their honey. We consider honey bees as being defensive rather than aggressive in nature. Bees will defend their hive, where they protect their food stores and brood, by stinging intruders, whether they are foreign bees, attacking wasps, hornets, skunks, bears, or humans. The honey bee’s sting is barbed. When we are stung by a honey bee, the barbs hold the sting firmly in our skin. As the bee pulls away, her abdomen is torn apart, a fatal injury for the individual bee. The bee’s sting and death, however, have a concentrating effect in protecting the hive. Left behind on the skin are the sting, venom sac, muscles pumping venom, and glands emitting alarm pheromone. Alerted hive bees readily follow the intruder and add more stings.

Honey bees from other hives are the most common attacker of hives. Guard bees at the hive entrance check bees attempting to enter the hive. Since the bees from each hive have a distinct odor, the guards turn away intruders. If a guard stings an intruding bee, her sting usually pulls out of the victim’s soft exoskeleton without fatally injuring the guard bee. Gentleness in honey bees is an inherited trait, and beekeepers select for bees that are gentle. Helping control the behavior of bees is one of the ways beekeepers serve their communities. Even though beekeepers learn how to safely handle bees, it is important for them to always protect their eyes from stings. Beekeeper Mary Phillips Riddle wears a protective veil while working with the bees.