Cover Story
Cover Story July 2010
(excerpt)
American Bee Journal Editor - C. P. Dadant
When George W. York, editor of the American Bee Journal from 1892 until his sales announcement in the May 1912 issue,1 was looking for an opportunity to start a new life in the West, he was faced with the problem of disposing of the American Bee Journal. Consequently, his thoughts turned to C. P. Dadant who had been a faithful contributor to the Journal for some 40 years.
Although York had contributed to the columns of the Journal for a long time, and was the editor and publisher for 20 years, he actually was not a thoroughly experienced beekeeper, being more of a theorist and interested in the development of beekeeping rather than in the actual operation of a beekeeping business.
With C. P. Dadant, it was a different matter. Coming to America in 1863 at the age of 12 with his father, Charles Dadant, he had to take an active role in providing a living for the family. He actually was doing more in agricultural work-until the opportunity arrived.
Soon after the family settled near Hamilton, Illinois, Charles Dadant bought two colonies of bees, and he gradually increased the number of colonies. As time passed, the natural resources of flora caused the colonies to prosper and he found it necessary to call on his son to help with the care of the bees. This was to signal a big change in C. P.'s life.
Camille Pierre (for that is what C. P. stands for) soon became the main operator of the home apiary and gradually expanded to outyards in the search of better locations, moving colonies to harvest honey during the fall flows in the bottom lands along the Mississippi River. These moves were made, of course, with wagons since automobiles were not available yet.
Although his father was writing extensively for American and especially foreign journals, at first, C. P., of necessity, devoted but a small part of his time to writing. It can be assumed that he helped his father in writing for English publications since Charles found the language difficult, and some of the articles are authored by Chas. Dadant & Son.
C. P.'s first contribution to the American Bee Journal was entitled "Review of Foreign Bee Journals," and appeared in the May 1872 issue.2 This was followed by an article in the June 1872 issued entitled "Introducing Queens."3 Naturally, in these early years he didn't have too much time to devote to anything but bees in order to earn a livelihood. His records show that, as early as 1882, he had extracted 25,000 pounds of honey, which was an enormous crop for anyone at that time. Nevertheless, his contributions to the Journal amounted to as many as six in 1885, nine in 1890, eleven in 1896, and these increased, as he had more time to devote to writing, to as many as 32 in 1906. The latter was after he had retired in 1904, leaving the bees and the comb foundation business to his three sons, Louis, Henry and Maurice.
Prior to assuming editorship of the American Bee Journal in 1912, C. P. Dadant is listed as a contributor upwards of 350 times. A concise reporting isn't made here because some of the volumes were not indexed as to contributors and some articles are listed by Chas. Dadant & Son. His contributions in 1906 marked the beginning of his series entitled "Dadant Method of Honey-Production,"4 and ran through 21 issues. The article No. 22 entitled "Dadant Methods of Vinegar-Making with Honey" appeared late in the same year.5
After assuming the editorship in 1912, C. P. Dadant is listed as a contributor to the Journal some 460 times, before his declining health in 1937 and death in 1938. His largest number of contributions occured in 1927 when 46 articles were listed.
We might interject here that, after a busy life and after his sons had entered the business during the period from 1900 to 1910, C. P. Dadant decided he would retire and lead a quiet life. So, in 1904, he built a large brick house in Hamilton and retired.
With C. P., however, the quiet life did not prove entirely satisfying. He found time hung heavy, so he took pleasure in acquiring the American Bee Journal in 1912 and moving it to Hamilton.
The Journal offices were moved to the floor above the First National Bank in Hamilton. This was quite an undertaking for C. P. and soon he looked around for help. Dr. Miller, as associate editor, answered questions and was of editorial help, but remained at his home in Marengo, Illinois.
Cover Story - June 2010
My Recipe for Successful Beekeeping
Excerpt
After being away from beekeeping over 25 years, I started helping some friends with their hives in 2007. Because of the pest and health issues facing honey bees today, I had to re-learn beekeeping. It was difficult because there was too much information available.
Many beekeeping authors - even most - hesitate to say, ‘This is how to do it.' And for good reason. There are so many variations in honey bee behavior, weather, diseases, pests, environment and everything else that it's impossible to be definitive. Details and possible variations are usually included to avoid misleading anyone. The unintended consequence is that people with only a few years experience in beekeeping can read stacks of beekeeping literature and still not know what to do in their bee yard. Too many details confuse people. Even with 20+ years of beekeeping experience, it was difficult for me to find a reasonably simply way to deal with today's beekeeping environment. After nearly two years of study, experimentation and hard work, Clyde Hammil (my partner) and I developed a simple procedure for successful beekeeping.
Instead of trying to cover all the possible variations, I will explain step-by-step what has to be done in the bee yard, why we have to do it and when we have to do it. Honey bees will no longer thrive on neglect. Some actions by the beekeeper are required. Those critical actions will be highlighted in red. I won't nag or call you a ‘bee-haver', but if you do not have the time and discipline to take these few required actions at the right time, your colonies will be weak, will not produce surplus honey and are likely to die out. That's just the facts of today's beekeeping.
Certainly, this procedure is not complete. Read all the books you can, join a beekeeping club and talk to experienced beekeepers. Really good beekeepers want to know all we can about honey bees. But keep this simple guide close at hand. A lot of things can go wrong, but they usually go right!
My experience is in south Arkansas. People farther north will have to adjust the suggested actions to the calendar and conditions in their area. If you have corrections or suggestions, by all means, let me hear them. My email is: jfreeman1944@yahoo.com. My phone number is: 870-853-2412.
JULY - Extract honey and TREAT FOR VARROA MITES
For me, the beekeeping year begins in July. Our honey flow has ended and the VARROA MITE population is beginning to explode. (for beekeepers farther north, you will need to move that month to sometime in August.) I extract honey the first part of July and treat for Varroa beginning in the middle of July. The chart shows why Varroa mites are such a threat in summer and early fall. I realize some people still have a honey flow in July, Aug and even September, but fall treatment of Varroa is too late. The colony must raise healthy babies in the fall to produce honey next year! If the fall brood has been chewed on by Varroa mites, they will not be healthy enough to build a strong colony for next spring.
Hygienic queens may solve the problem for you, but you need to make sticky board counts to be sure the mites are under control. (I use the oil tray in our beetle trap for a sticky board.) Randy Oliver's web site, http://www.scientificbeekeeping.com/, provides more details.
Most of my bees are not hygienic enough to deal with Varroa on their own. I make two treatments with Apiguard - the first one in the middle of July and the second one two weeks later. I use Apiguard for two reasons. First, it is effective. Second, it is not a poison. The active ingredient in Apiguard is Thymol - made from the herb, Thyme. This is the only ‘chemical' I use in my colonies. I believe chemicals and poisons are major contributors to the current decline in honey bee health.
Formic acid is also a natural ingredient, but is much more harsh than Apiguard. It kills some brood and may even damage the queen. GOOD NEWS! The makers of Mite-Away-II, formic acid pads, have developed a new product called MAQS - Mite Away Quick Strips. They claim it is so mild it can be used even when honey supers are on the hive. It has not yet been approved, but surely will be by next year. This means that even beekeepers with summer honey flows will be able to treat their colonies when the Varroa mite population is expanding
Cover Story - May 2010
Proceedings of the American Bee Research Conference
Excerpt
1. Afika, O., W.B. Hunterb & K.S. Delaplanea - Effects of varroa mites and bee diseases on pollination efficacy of honey bees - Varroa mites and viral diseases are known to affect the efficiency of crop pollination by honey bees through the elimination of colonies, but only limited information exists on their influence on pollination at sub-lethal levels on the individual bee (Ellis & Delaplane, 2008 Agr. Ecosyst. Environ. 127:201-206). The purpose of this study was to learn about effects that varroa mites and bee diseases may be having on the foraging behavior of adult bees and the consequences of these effects on successful fruit pollination.
For the first season of the experiment, four honey bee colonies of about 4,500 bees each were established. Two of these colonies were each infested with 1,000 varroa mites collected from other hives by sugar powdering. Two other colonies were used as non-infested control colonies. In order to force mites to attach to the adult bees, brood combs from both treatments were replaced with empty combs before brood was sealed. Each colony was caged in a separate enclosure containing one blueberry target plant and two potted pollen source plants. Pollination efficacy was tested by measuring percent of fruit-set and pollen deposition at flowers exposed to a single visit by an individual bee. Each visiting bee was collected at the end of the flower visit and preserved for later pathogen analysis.
The results indicated that bees from mite-infested colonies achieved a lower percent of fruit set and tended to deposit fewer pollen grains on the flower stigma. Bees from infested colonies performed shorter flower visits and a lower percentage of them were pollen foragers. These two behavioral differences may contribute to lower rate of fruit-set since the duration of flower visit was positively correlated with pollen deposition and pollen foragers were found to be more efficient pollinators of blueberry flowers than nectar foragers. More than 75% of the bees from both treatments were determined to be naturally infected with the viruses DWV and BQCV, but no bee was positive for Nosema spp., ABPV, IAPV or KBV. The results suggest that bees from colonies highly infested with mites are less efficient pollinators, possibly due to shorter visits to the flowers and lower tendency to collect pollen. The effects of mite infestation combined with high virus infections have not yet been determined. Further research will focus on how to limit the effects of varroa mites on the foraging behavior and pollination success of honey bees.
2. Alauxc, C., J.-L. Brunetd, C. Dussaubatc, F. Mondetd, S. Tchamitchand, M. Cousind, J. Brillarde, A. Baldyc, L.P. Belzuncesd & Y. Le Contec - INTERACTIONS BETWEEN NOSEMA MICROSPORES AND A NEONICOTINOID IN HONEY BEES - Massive honey bee losses have been reported in the world, but the specific causes are still unknown. Single factors, like pesticide impact, or a disease or parasite have not explained this global decline, leading to the hypothesis of a multifactorial syndrome (van Engelsdorp et al., 2009 PLoS One 4:e6481). Consequently, we tested the integrative effects of an infectious organism (Nosema sp) and an insecticide (imidacloprid) on honeybee health. We demonstrated, for the first time, that a synergistic effect between both agents, at concentrations encountered in nature, significantly weakened honey bees. The combination of Nosema, a pathogen whose importance is emerging, with imidacloprid caused a significantly higher rate of individual mortality and energetic stress in the short term than either agent alone. We then quantified the strength of immunity of honey bees. While the single or combined treatments showed no effect on individual immunity (haemocyte number and phenoloxidase activity), a measure of colony level immunity, glucose oxidase activity, was significantly decreased only by the combined treatments, emphasizing their synergistic effects. Glucose oxidase activity enables bees to secrete antiseptics in honey and brood food. This suggests a higher susceptibility of the hive to pathogens. We, thus, provide evidence for integrative effects of different agents on honey bee health, both in the short and long term. By focusing either on the effects of pesticides or parasites alone, previously established synergy has been ignored, despite clear evidence from integrated pest management that entomogenous fungi act synergistically with sub-lethal doses of pesticides to kill insect pests (Alaux et al., 2009 Environ. Microb. doi:10.1111/j.1462-2920.2009.02123.x).
3. Andinof, G.K. & G.J. Huntf - A NEW ASSAY TO MEASURE MITE GROOMING BEHAVIOR - Grooming behavior is one of the known mechanisms of defense for honey bees against parasitic mites. Varroa destructor is often considered the biggest beekeeping problem within the U.S. and around the world. Mite-grooming behavior has been described as the ability of the adult bees to remove Varroa mites during grooming and has been associated with mites that have been chewed by the bees' mandibles, but the proportion of chewed mites is extremely tedious to measure.
We developed an easier assay to measure mite-grooming behavior that can be used for selection in breeding programs. Wood cages with screened tops and bottoms were used to hold a frame of bees collected from the brood nest. Bees were transferred to comb containing pollen and nectar but without brood. The mites removed during grooming were collected in sticky boards for three days at room temperature (22-25 °C) and then counted. The remaining mites on the adult bees were collected and counted using carbon dioxide (CO2) to anesthetize the bees and powdered sugar to remove the mites. The percentage of the mites removed was calculated.
A significant relationship (p = 0.0285) was found between the proportion of mites removed in the lab assay and the proportion of chewed mites on sticky boards from the source colonies. This relationship indicates that the colonies that removed the highest percentage of mites in the caged adult bees were also the colonies that had the highest percentage of chewed mites (Figure). These results suggest that the method used to measure mite-grooming behavior is effective. In addition, we also found a negative relationship (p = 0.0072) between the percentage of mites removed and mite infestation of adult bees, which indicates that the colonies with the highest percentage of mites removed in the cage assay, had the lowest population of mites on adult bees. These results suggest that the low population of mites present on the adult bees is due to grooming.
4. Bahreinig, R. & R.W. Currieg - INCREASING THE ECONOMIC THRESHOLD FOR FALL TREATMENT OF VARROA MITE (VARROA DESTRUCTOR A.&T.) IN HONEY BEES BY USING MITE-TOLERANT STOCKS IN NORTHERN CLIMATES - The objective of this research was to develop effective and economical methods to reduce the impact of varroa mites on honey bees under winter management systems. Fall economic thresholds for varroa mite control in the prairie region of Canada suggest producers should treat honey bee stock when the mite level is greater than 4 mites per 100 bees (in late August to early September) to prevent fall or winter colony loss (Currie & Gatien, 2006 Can. Entomol. 138:238-252). However, it is not known how the use of mite tolerant stock or late season acaricide application would affect these thresholds. An experiment to assess these factors was carried out at University of Manitoba in fall 2007 to spring 2008. Thirty-nine colonies from mite-susceptible (n=23) and mite-tolerant (n=16) stocks with mite levels (16±3 mites per 100 bees) above the fall economic threshold were chosen and within each type of stock were randomly assigned into two groups that would either receive a late fall (November 2007) treatment with 1 g of oxalic acid crystals or were left untreated. Colonies were randomly arranged in two small rooms in a wintering building maintained at 5°C. Colony worker population and mean abundance of varroa mites were assessed before and after wintering colonies, and varroa mite and worker mortality rates were determined.
As expected, late fall treatment with oxalic acid reduced the mean abundance of varroa mites over winter (to 3.5%), relative to that found in untreated colonies (12%) in both susceptible and tolerant stock as indicated by a significant acaricide treatment × season interaction (P<0.01). However, under high fall mite load, reductions in mite levels associated with late-season oxalic acid treatment did not improve colony survival relative to untreated colonies. The use of mite-tolerant stock improved colony survival. In the mite-tolerant stock winter survival of colonies was much higher (75%) than in mite-susceptible stock (43%). The populations of worker bees in mite-tolerant and mite-susceptible stock were similar in colonies that survived winter. Bee populations in tolerant stock tended to be slightly higher than in susceptible stock, whether colonies were treated with acaricide or not. Untreated colonies with tolerant and susceptible stocks had similar mite mortality rates over winter, but tolerant stock had slightly a lower mean abundance of mites at the end of winter, compared to susceptible stock. Overall, this study demonstrates that when late fall mite levels are well above the fall economic threshold, tolerant stock could be used by beekeepers to help minimize colony loss in the Canadian prairies and under these conditions late fall oxalic treatments may not improve colony survival.
5. Cobeyh, S., J. Pollardi, C. Plantei, M. Flennikenh & W.S. Sheppardj - Development of A PROTOCOL for THE International Exchange OF HONEY BEE GERMPLASM - The development of protocol for the safe, well regulated international exchange of honey bee genetics is needed. The current ban on importation is inconsistent and has failed to prevent the spread of pests, parasites and pathogens. The initial limited gene pool introduced into the U.S. before the 1922 ban and the alarmingly high loss of colonies due to Colony Collapse Disorder is an increasing concern. Genetic diversity has been demonstrated to increase colony fitness and reduce the impact of pests and diseases. Our project is designed to develop technologies to safely import honey bee germplasm, semen and eggs, and to import stocks selected for resistance to enhance our domestic honey bee gene pool.
An improved bee semen extender with an antibiotic mixture, containing gentamicin, amoxicillin, lincomycin and tylosin, specifically designed to control bacterial pathogens was developed and tested to facilitate the transport of semen. Extended semen was examined for viability and motility after storage for 7 days, and inseminated to virgin queens. Results demonstrated high sperm viability, normal spermathecal sperm counts and normal brood patterns of inseminated queens.
USDA-APHIS (Animal Plant Health Inspection Service) permits were obtained and honey bee semen imported. Apis mellifera ligustica from survivor stock in Italy and A. m. carnica from the Germany Carnica Association were imported in 2008 and 2009 and crossed with domestic stocks. The semen was tested for viruses and resulting colonies established in an approved quarantine area at Washington State University. Progeny of these colonies were also examined and tested for pathogens. The 2008 imports released were backcrossed to the 2009 imports to create more pure stocks and also were incorporated into proven commercial U.S. stocks.
The New World Carniolan × German A.m. carnica colonies expressed increased fitness and increased expression of hygienic behavior. The Italian stock is still undergoing testing. Future plans are to import A.m. caucasica, as this subspecies is detectable but largely unrecognizable in the U.S.
Honey bee eggs represent a complete genetic package and are available in large quantities. Therefore, we developed reproductive technologies to manipulate honey bee eggs to allow for their isolation, pathogen testing and transport. A method to manipulate embryos was developed using fine forceps modified by the application of micro-bore tubing. The transferred eggs were hatched in vitro and the larva were grafted into queen cell cups, reared into queens and instrumentally inseminated with a high rate of success.
6. Delaplanea, K.S. & J.A. Berryk - TEST FOR SUB-LETHAL EFFECTS OF SOME COMMONLY USED HIVE CHEMICALS, YEAR Two - We are involved in a two-year, two-state (GA, SC) experiment examining sub-lethal effects of selected bee hive chemicals; the list includes registered products at label rates, as well as two off-label formulations. The reason we are doing this is that there is evidence that some of the chemicals used in beekeeping are hazardous to bees and contribute to bee decline (Frazier et al., 2008 Am. Bee J. 148(6):521-523; Desneux et al., 2007 Ann. Rev. Entomol. 52:81-106). Understanding this piece of the CCD puzzle will help beekeepers move toward more chemical-independent management. Here are results for two years from Georgia. Varroa levels (mites/100 bees) were significantly higher in CheckMite (coumaphos)-treated colonies than in colonies treated with Taktic (amitraz); mite levels were intermediate in all other treatments. Bees in the non-treated control colonies exhibited numerically highest brood viability, homing ability, and foraging rate and numerically lowest incidence of queen supersedure cells. Information like this is important for evaluating the cost:benefit ratio of using exotic chemicals in honey bee management.
7. Desaig, S. & R.W. Currieg - INHIBITION OF DEFORMED WING VIRUS (DWV) MULTIPLICATION IN HONEY BEES BY RNA INTERFERENCE - DWV plays a major role in affecting honey bee health. High proportions of colonies are infected by this virus, and it can be detected in worker honey bees, queens, pupae, larvae, drones and also in varroa mites. DWV and its interactions with the ectoparasitic varroa mite and other diseases have caused significant mortality of honey bee colonies on a world-wide basis (Miranda & Genersch, 2009 J. Invertbre. Pathol.103:S48-S61).
RNAi is a comparatively "simple", rapid and specific method for silencing gene function and can be developed to be specific to an individual virus. RNAi has recently been utilized in a number of species including human beings, plants, animals and insects (Drosophila) and recently in bees to suppress viruses. For example, successful silencing of Israeli Acute Paralysis Virus (IAPV) in honey bees by feeding specific dsRNA to bees dramatically improved bee-to-brood ratio and honey yield (Maori et al., 2009 Insect Mol. Biol. 18:55-60).
RNAi reduces virus replication by causing degradation of the target mRNA. In this experiment, we assessed the effects of feeding dsRNA constructs against DWV to larvae that were infected with DWV and the potential lethal and sub-lethal effects on developing worker bees.
In DWV-infected larvae fed dsRNA survival (45%) was greater than the survival of larvae fed unrelated dsRNA (GFP) (31%) or DWV-infected larvae that were not treated with dsRNA. The dsRNA did not affect larval survival as DWV-"free" larvae fed our dsRNA construct had similar survival to that of untreated controls (Figure). Our dsRNA-fed larvae that were infected with DWV had significantly lower levels of wing deformity compared to larvae infected DWV or to larvae infected with DWV and an unspecific form of RNAi (GFP). Our experiment also demonstrated for the first time that feeding DWV orally in the absence of mites causes wing deformity in in-vitro reared larvae. We hypothesize that application of dsRNA into the honeybees fed DWV should result in a reduction in DWV titer over time with no effect on bee longevity. If proven effective, this mechanism can be used to block DWV and could improve winter survival of honeybee colonies.
8. Eischenl, F.A., R.H. Grahaml & R. Riveral - MOUNTAINSIDE WINTERING IMPROVES COLONY STRENGTH AND SURVIVAL OF HONEY BEES IN SOUTHERN CALIFORNIA - We examined the interaction of a feeding program and cold-windy conditions on honey bee colonies near Santa Ysabel, California (elev. 914 m). An equal number of colonies located near Fallbrook, California (elev. 219 m) served as controls. The trial began 7 September 2008 near Holtville, California (Imperial Valley). Colonies were randomly assigned to four treatment groups (n = 50), i.e., 1) Highland, fed continuously, 2) Highland, fed discontinuously, 3) Lowland, fed continuously, and 4) Lowland, fed discontinuously. On 20 November, lowland-designated colonies were moved to their normal winter locations near Valley Center, CA, and highland colonies to a mountainside near Santa Ysabel, CA. Groups 1) and 3) were fed continuously throughout the trial. Groups 2) and 4) were not fed during the period 6 Dec. 2008 - 13 Jan. 2009. Colonies were evaluated for strength and broodnest size on 26 January 2009, i.e., near the time of almond pollination evaluation.
Regardless of feeding treatment, highland colonies at the end of the trial were stronger by about 1.5 frames of bees than colonies of either lowland group. Brood nests of highland colonies were smaller, however by about 1.0 frames of brood. Stored pollen declined in the highland colonies, but stayed about the same in the lowland colonies; indicating that pollen foraging occurred in the lowland colonies. Highland colonies had a slight, but significantly higher survival rate than did lowland colonies.
To determine if the highland colonies would lose strength on return to lowland conditions, colonies from each treatment group (n = 25) were moved to an almond orchard near Shafter, CA and examined on February 15. Highland colonies were nominally larger than lowland colonies. Broodnest sizes were about the same for both highland and lowland colonies. Highland colonies had significantly more stored pollen than lowland colonies, indicating that their larger size caused increased pollen foraging. A simplified cost/benefit analysis indicates that it was economical to place colonies in a climate that limits unproductive flight during winter.
9. Eischenl, F.A., R.H. Grahaml & R. Riveral - ALMOND POLLEN COLLECTION BY HONEY BEE COLONIES HEAVILY INFECTED WITH NOSEMA CERANAE - In 2007 apiculturists became aware that the microsporidian, Nosema ceranae, had become established in the United States. A related species, N. apis is a well known honey bee pathogen. There was concern within the beekeeping industry that this "new" pathogen is part of the Colony Collapse Disorder (CCD) phenomenon.
A commercial beekeeper, based in Louisiana and New York, was found to have high levels of this pathogen in colonies used to pollinate almonds, blueberries and cranberries. We examined the impact of four N. ceranae levels on honey bee colonies including pollen collection during almond bloom in the Central Valley of California during February - March 2009.
N. ceranae levels in October 2008 were on average 1.0 - 2.9 million spores/bee (MSPB). By January 2009, levels increased to, on average, 1.6 MSPB in the lightest infection group to 49.5 MSPB in the heaviest. After transport from Louisiana to California during 31 Jan.-2 Feb, colonies in the two heaviest-infected groups had striking declines in their spore levels. We suspect the rigors of travel caused many severely infected bees to die.
Pollen collection by the lightest-infected colonies (Group I) was about twice that of Group II (159.8 vs. 74.0 g/day). Both Group I (0-4.5 MSPB) and Group II (5-15 MSPB) colonies collected significantly more pollen than Groups III (16-34 MSPB) and IV (35-49 MSPB) 16-34. When pollen collection was based on grams of pollen per frame of adult bees, we found that Group I colonies collected significantly more pollen. This suggests that foragers with heavy infections either make fewer collecting trips or pack smaller loads or both.
Colonies of all four groups lost significant adult bee strength during almond bloom, but losses were more severe in Groups II, III, and IV. At the end of pollination, no significant differences in N. ceranae spore levels were found among treatment groups, but levels rose in Groups I and II, while remaining about the same in Groups III and IV.
We suspect that these colonies, especially those with high spore levels, had large spore reservoirs on their honeycombs. We recommend including this factor when determining economic thresholds.
10. Eitzerm, B., F. Drummondn, J.D. Elliso, N. Ostiguyp, M. Spivakq, K. Aronsteinl, W.S. Sheppardj, K. Visscherr, D. Cox-Fosters & A. Averillt - PESTICIDE ANALYSIS AT THE STATIONARY APIARIES - One facet of the stationary apiary project within the "Sustainable Solutions to Problems Affecting the Health of Managed Bees Coordinated Agricultural Program" is a monitoring of the honey bee's exposure to pesticides. This is being done by determining pesticide residues in the pollen that is brought back to the hive by foraging honey bees. At five hives from each of the stationary apiaries, pollen is sampled with traps one day per week. Pollen samples are frozen after collection. Aliquots from all samples taken from an apiary during a calendar month are combined to generate a monthly composite sample for each apiary. Five grams of this composite sample are analyzed by a multi-pesticide residue procedure. In brief, the samples are extracted with acetonitrile using a dispersive solid phase technique known as QuEChERS (for Quick, Easy, Cheap, Effective, Rugged and Safe) and analyzed using high performance liquid chromatography/mass spectrometry/mass spectrometry. Using this technique allows over 140 different pesticides to be analyzed in the parts per billion (PPB) concentration range.
To date 29 of the monthly composite samples have been analyzed. Within these 29 samples, residues of 32 different pesticides or pesticide metabolites have been observed including: 14 insecticides plus one insecticide metabolite, 9 fungicides and 8 herbicides. The average composite pollen sample had an average of 4.1 pesticide residues detected. The concentration of residues when detected are mostly in the low PPB range (1< to 30 ppb), but some residues were substantially higher. The results indicate that honey bees at the stationary apiaries are being exposed to varying amounts of pesticides. As might be expected, this exposure amount varies with the location of the apiary (i.e. honey bees in Washington are exposed to different pesticides than those in Florida) and time of year. In addition, analysis of non-composited samples taken from five different hives within the same apiary on the same day also shows different pesticide amounts. This indicates that the honey bees from these hives are clearly foraging from different fields that have had different amounts of pesticides applied. This variability of pesticide exposure will be further examined as we continue to monitor these hives over the next several years.
11. Esaiasu, W. - RELATIONSHIPS BETWEEN VEGETATION COVER, NECTAR AVAILABILITY, AND THE AFRICANIZED HONEY BEE - Collections of scale hive records of the Honey Bee Nectar Flow reveal dramatic regional variations related to honey bee forage and its phenology, and are used to quantify inter-annual variations that are related to changes in land cover type (nectar sources) and natural climate change. Temporal trends in the nectar flow dates correlate well with trends in vegetation parameters observed with the Moderate Resolution Imaging Spectroradiometer on the Terra and Aqua satellites. Nectar flows are generally occurring earlier in the Northeast U.S., and later in the Southeast U.S., in conjunction with regional increases in winter minimum temperatures. Numbers of volunteer beekeepers who provide records of daily weight changes has been doubling for the past several years and is now approaching 100 locations throughout the U.S. Further insight into climate and land cover change impacts on the timing of nectar flows will be possible as the number of volunteer locations increases, especially in the central and western U.S. Maps of site locations coverage, and scale hive data itself, are available at http://honeybeenet.gsfc.nasa.gov. Research programs establishing longer term monitoring apiaries are encouraged to consider monitoring hive weight changes to evaluate the impact of inter-annual nectar flow variations on colony health and behavior.
Jointly with the USGS National Institute of Invasive Species at Ft. Collins (C. Jarnevich, J. Morisette, T. Stohgren), climate and satellite vegetation data and species distribution models (SDMs) are used to better understand the areas at risk from further advance of the Africanized Honey Bee, and to shed light on why its movement into eastern Gulf of Mexico states has been slow compared to movement to the north and west. A key limitation to these studies, based on presence of an invasion still in progress, is the relatively poor knowledge of exact AHB locations throughout the range, although some states are very well sampled. Additionally, the sampling is biased spatially, makes no distinction between overwintered versus incidental/transient transport, and sampling effort is not uniform or recurrent over time. With 1-5 km scale resolution, model depictions of areas having similar climate and vegetation to the AHB presence locations appear to be very robust in the Southwest U.S. (west of 190 W) using the Maxent model. Winter and summer temperatures and vegetation parameters were critical variables. Maxent does not give satisfactory results for the Southeast U.S. yet. There, sampling biases are extreme due to presence data only in the western portion and extreme southeastern (S. FL) portion of the region. However, initial software test runs using an ensemble approach with 5 different SDMs appear to provide very useful maps of suitable AHB regions for the U.S., with further refinement required. Based on those very preliminary results and the small number of historic and current nectar flow records available, there is complete correspondence between areas of AHB presence/absence and abundance/dearth of nectar in the late summer and fall. This suggests that the combination of physical climate and the bulk vegetation phenology data from satellite observations can provide useful insight into local nectar flow phenology, at national scales.
Contributors to this project are R. Wolfe, P. Ma, J. Nightingale, and J. Nickeson at GSFC, C. Jarnevich, T. Stohlgren, J. Morisette at USGS Ft. Collins, J. Pettis at ARS/USDA Beltsville, J. Harrison at Arizona State Univ, J. Hayes at FL DACS, D. Downey at UT DAF, and the HoneyBeeNet Volunteers. Funding is from the NASA Earth Sciences Applications - Decisions Program.
12. Fellv, R., C. Brewsterv, & A. Mullinsv - The Spatial Distribution of Varroa Mites in Honey Bee Hives - Studies on the intra-hive distribution of Varroa mites were designed to obtain a better understanding of the spatial distribution of mites, how these patterns change over time, and how this information might be used to improve sampling and treatment decisions. Mite populations were sampled in a group of eight experimental hives (consisting of 1 full-depth hive body or 1 full-depth and 1 medium depth) three times at two-week intervals from mid-August to early October. PSU/IPM sticky boards were used for sampling, but were modified to cover the entire bottom board of a hive. Sticky boards were left in hives for 3 days. After removal, mite numbers were counted in each grid square (1.8 x 1.8 cm) and used to establish a distribution matrix. A geostatistical approach utilizing GS+ and Matlab® (MathWorks Inc., Natick, MA) software was used to analyze the mite sampling data and to build spatial models of mite distributions that can be displayed as surface density maps (Figure). Brood distribution in each hive was also measured after mite sampling using digital images. Frames were removed and photographed on each side with respect to their position in the hive and then divided into a set of data cells that corresponded with the sticky board grid. Frame contents were categorized as brood (worker, drone, capped, uncapped) or non-brood. Mite and brood sample distributions were further analyzed using spatial analysis by distance indices (SADIE).
The results show mite distributions were aggregated or clumped, and significantly associated with brood distributions (Index of association [Im] values varied from 0.23 - 0.58, Pm < 0.0001). Surface density maps indicate that bee collection for mite sampling using techniques such as the powdered sugar roll should be made in or near the brood nest. The results of this study also indicate that mite-sampling data can be highly variable. Mite numbers from sticky board samples were found to vary by as much as 250% in as little as two weeks. These data make it difficult to set mite number thresholds for beekeepers to use when making management decisions for colony treatment. Colonies deemed below a treatment threshold may show mite populations significantly above the threshold two weeks later when sampled in late summer and early fall. The association between brood and mite distribution also suggests that brood frame manipulation might provide an effective management tool for altering mite distributions for targeted treatment approaches.
13. Frostw, E.H., D. Shutlerw & K. Hillierw - EFFECTS OF A MITICIDE ON HONEYBEE MEMORY: IS THE CURE WORSE THAN THE DISEASE? - Significant mortality from Varroa destructor has occurred in wild and managed honeybee populations. Although mortality is the clearest indicator of negative consequences, Varroa may have other subtle effects. For example, chemical treatments used to eliminate Varroa may interfere with the honey bees' ability to properly integrate stimuli that elicit feeding, mating, colony defense, and communication behaviors.
We assessed learning and memory of honey bees exposed to tau-fluvalinate, the active ingredient in Apistan®, using a standardized Pavlovian insect-learning paradigm (proboscis extension reflex [PER]), that mimics learning in the natural environment. Honey bees are presented with a neutral stimulus, usually an odor, followed by a positive reward such as sugar water. Honey bees learn to extend their proboscis when exposed to the odor, in the absence of a reward, because the odor predicts the presence of food. Stressors, such as pesticides may reduce the frequency of PER, suggesting impaired learning (e.g., Abramson et al., 2004 Environ. Entomol. 33:378-388; Decourtye et al., 2005 Arch. Environ. Contam. Toxicol. 48:242-250).
Forager honey bees were collected in Nova Scotia, Canada in August/September 2009 and immobilized with only their antennae and mouthparts free. Tau-fluvalinate, dissolved in 1.25 µL of acetone, was applied dermally (thorax) or orally (proboscis) at concentrations of 0.125 µg (estimated to be daily exposure per bee in treated hives [Johnson et al., 2009 J. Econ. Entomol. 102:474-479]) or 1.25 µg. Controls were treated with 1.25 µL of acetone. Bees were trained to perform PER (training trials), and then tested for retention of odor memory 24 hours later (extinction trials).
Lower dose treatments had no significant effect on mortality or PER during training or extinction. At the 1.25 µg dermal dose, mortality was significantly higher in treated honey bees than controls at both 3 and 24 hours post treatment (p = 0.001 and p < 0.0001, respectively). Controls had a significantly higher average number of PER responses to odor cues during training (p = 0.05); there was no significant effect during extinction trials (p = 0.08).
We are also quantifying how tau-fluvalinate is partitioned within the honey bee body, and the relative concentrations. Chemical residues are evaluated using gas chromatography mass spectrophotometry by isolating the head and thorax and placing them in hexane to extract tau-fluvalinate. Quantities of tau-fluvalinate are measured by the size of the peaks on the chromatography output relative to a standard curve. Preliminary results suggest tau-fluvalinate enters the honey bee circulatory system after dermal contact. Honey bees with a dermal application (thorax) of tau-fluvalinate also have traces of the chemical in their head. Detoxification may also occur over time, with decreasing levels of tau-fluvalinate present in honey bee tissues over a 24 hour period.
Ultimately, this research will lead to standardized methods to evaluate suitability of mite treatment programs and potential sublethal effects of chemicals on honey bee
Cover Story - March 2010
An Adaptable Work Force
Excerpt
by Randy Oliver
I'd like to return to the analogy of the honey bee colony as being similar to a medium-sized mammal. The combs are analogous to the skeleton, the queen to the ovary, drones to sperm, honey to body fat, and the workers to the individual cells that make up organs.
The honey bee superorganism has one up on a mammal, though-a mammal can't "dissolve" unneeded or overrepresented organs, and shift those cells to augment other organs. A colony of bees can-by shifting workers from one task to another. This plasticity in worker task specialization allows the colony to quickly respond to changes in the environment-such as a sudden bonanza of nectar, or the need to shift from broodrearing to winter cluster formation. However, in order to undergo such transformations at maximum efficiency, the individual bees of the colony must be able to share information. Such sharing is done via the commerce of foods (analogous to the mammal's circulatory system), and through the bees' pheromonal language (analogous to a colony nervous system).
Allow me to return to the concept of the hive economy, which is driven by floral resources, and to the female labor pool that processes them. (Drones do not participate in within-colony labor other than in heat production. That leaves the two castes of females-the queen or queens, whose only labor is to lay eggs, and the omnicompetent and versatile worker.) By having only one sort of generic yet adaptable worker, that can specialize in short order to fill any task, the colony's workforce can rapidly shift from one job to another, as opportunities or challenges arise, so as to ensure that the economy of the hive functions most efficiently.
Seeley (1995) points out that much "communication" within the hive is by cues, rather than actual communicative signals. This is especially true with communicating the status of the state of nutrition within the hive. The feedback of cues (such as amount of jelly, or the ease of unloading nectar) forms the bulk of communication from the colony to the individual. Only a few signals (the dances, alarm and orientation pheromones, etc.) allow the individual to directly communicate to the colony as a whole.
Human economies respond to the dynamics of price-the more valuable goods get more economic attention. The same occurs in the hive-and foragers respond to cues that tell them how valuable certain commodities (rich or dilute nectar, water, or pollen) are at the moment. In response, the individual foragers invest work effort proportionally to the current value of each commodity, not for individual gain, but rather for the maximum gain of the colony as a whole.
Thus, a web of information sharing within the hive allows it to function without a central brain or government. Rather, the myriad feedback loops based upon food cues and pheromones allow the entire colony to act as a "mind" that allocates the labor pool to efficiently exploit the ever changing market of available resources upon which the hive economy is based-the pollen and nectar of the flowering plants that have coevolved in a mutually beneficial symbiosis with the bees. (Bees are the "shoppers" in the pollen market; plants advertise with bright petals and fragrant scent for bees to "buy" their product, and reward the shoppers with energy-rich nectar to fuel their shopping sprees.)
The godmother of hive dynamics was Dr. Anna Maurizio (1950), who found that workers in queenright colonies starved for pollen would transform into long-lived "winter" (diutinus) bees, even in summer. In the past several years the combined research of others has culminated in a considerable understanding of how nutrition and pheromonal feedback regulate colony economics and population dynamics.
Cover Story - February 2010
Strategies to Lower Your Tax Liability
Excerpt
by Howard Scott
As beekeepers, we all have the obligation to file all honey sales. For most of us, it's a sideline income. But that still doesn't exempt you from listing beekeeping revenue. The IRS states that all worldwide income must be entered on the tax return, whether $10 or $10,000. Furthermore, non-compliance can be fraud, which could result in serious penalty.
But, at the same time, the IRS allows us to subtract all expenses from the inflow, to arrive at a net profit. It is the net profit which is taxed. Whether you file a Schedule C (self-employment) or Schedule F (farming) or hobby income (revenue on line 21 of the 1040 and expenses on Schedule A), we file these expenses associated with our beekeeping activity.
In this article, I will offer five strategies to lower net profit, which in turn will minimize your beekeeping-activity tax liability (the amount of taxes you pay on your return).
? Home office deduction. Home office deduction can be used when the beekeeper uses a portion of the house regularly and exclusively to do bee work. An example would be if if there is a honey house on the property, that conforms to the regularly and exclusively standards. However, if the beekeeper has a corner downstairs where operates his beekeeping activity, whether extracting, bottling, or maintaining hives, and doesn't do much else in this spot, that qualifies as a home office. If a beekeeper has a place where he does all his administrative work (orders supplies, keeps product, figures out prices, pays bills) and doesn't do much else, that too qualifies. The new home office rules state that if that exclusive place exists, one can add other space in the basement or garage, where product is stored, where supplies are kept, or where experimenting and tinkering is done, even if this space isn't exclusively used for beekeeping activities.
Cover Story - January 2010
The Story of the American Bee Journal--
The Beekeeper's Companion for 150 Years
Excerpt
The story of the American Bee Journal, its origin, and Samuel Wagner, the first editor, must be closely associated with the Rev. L.L. Langstroth. In 1851, Langstroth had invented his movable-frame hive. In September 1851, a few weeks after a call on Langstroth, the Rev. Dr. Joseph Frederick Berg, pastor of a church in Philadelphia, visited Wagner and told him about this extraordinary beekeeper, his movable-frame hive and his beekeeping methods. They agreed that Wagner should go and see for himself, but it was not until August 1852, almost a year later, that he was able to do so.
After visiting Langstroth's apiary and seeing his hive, Wagner made a decision at a personal sacrifice to himself. He had corresponded with Dzierzon, discoverer of parthenogenesis, proponent of a practical system of beekeeping and author of a book entitled Rational Beekeeping. He had received permission to translate the book into English to be published for the improvement of American beekeeping. Wagner had made the translation, but it was never published. Recognizing the Langstroth movable frame hive as superior, he decided to encourage Langstroth to write a book instead; for his part, he would place all his store of information at Langstroth's service.
Langstroth quickly prepared the copy for the first edition of his book with the assistance of his wife, and Langstroth on the Hive and the Honey-Bee, A Bee-Keeper's Manual appeared in May of 1853.
Inasmuch as there were already two bee journals published in Germany, Langstroth made this prediction: "There is now a prospect that a Bee Journal will before long be established in this country. Such a publication has long been needed. Properly conducted, it will have a most powerful influence in disseminating information, awakening enthusiasm, and guarding the public against the miserable impositions to which it has so long been subjected."
Wagner established the American Bee Journal and its first issue appeared in January 1861, and from the start he had Langstroth as a contributor as well as an advisor. But after one year of publication, the Civil War resulted in the suspension of its publication until July 1866, when it was resumed.
To quote from Pellett's History of American Beekeeping, "The history of the American Bee Journal has been the history of the rise of beekeeping, and the one is inseparably linked to that of the other. Before this first copy of the first bee magazine in the English language appeared, there were few of the implements now in common use among beekeepers. Conventions of beemen had not been held, a practical smoker had not yet been invented, queen excluders were unknown, comb foundation was still to be perfected, the extractor had not come into use, nor had commercial queen rearing been suggested.
Cover Story December 2009
The Future: Pesticides and Fungicides
by RANDY OLIVER
Dave Hackenberg once quipped that, "Beekeepers have become the ugly stepchild of agriculture." Despite their general disregard for us, perhaps there are lessons that we can learn from our agricultural stepparents.
Pest Resistance Management
Beekeepers worldwide, in their exuberant use of every miticide available, have accelerated the development of mites resistant to (surprise) every synthetic miticide to hit the market. Luckily, U.S. beekeepers have been thrown a lifeline at the last moment in the form of the latest "silver bullet"- Hivastan®. However, lest I sound critical, I'm not blaming them-varroa has been the worst thing ever to hit beekeepers-it just won't go away! To their credit, every commercial beekeeper I've spoken to is concerned about the sublethal effects of miticides upon his bees, and most have experimented with alternative treatments.
The problem of varroa resistance to targeted poisons is hardly unique to beekeepers-this is a common phenomenon in modern agriculture. Allow me to quote from the pesticide industry's own pest resistance management website (IRAC 2009):
"General insecticide use is no longer the answer to pest control. Insects have developed widespread, insecticide-defeating resistance to many traditional treatments, and the industry may not have enough resources to continually develop and supply the market with new products precisely when needed to replace old ones. Growers with resistance problems do not have enough time to wait for new chemistry. It is imperative that the effectiveness of available insecticides be conserved by growers through adoption of these management principles. By working together, insecticide resistance can be managed!" [emphasis mine]
Folks, the above statement comes from the very companies that sell pesticides! They are telling us that we'd better learn to use Pesticide Resistance Management (PRM) for our own bee pests-mites, bacteria, and fungi. PRM strategy uses three main tactics of pest control-cultural, biological, and as a last resort, chemical. In the case of varroa management, "cultural" would include such techniques as the making of splits and other biotechnical methods. "Biological" would involve mite-resistant bees or biocontrols such as fungi or viruses specific to mites (unfortunately, we don't yet have the latter at our disposal). We should no longer consider miticides to be the first mode of defense.
A key aspect of pesticide resistance management to extend the effective life of a pesticide is the concept of "refuge strategy"-that is, to make sure that a large "refuge" of untreated pests remains outside of the managed fields. These untreated (and therefore susceptible) pests are expected to move in after treatment, and to outbreed the few resistant pests that survive the treatment, thereby delaying the development of pesticide resistance.
Unfortunately, the refuge strategy is problematic with varroa for two main reasons: (1) varroa normally mate brother to sister, so resistance alleles are difficult to breed out (shy of completely exterminating any colonies with resistant mites), and (2) because any miticide with a long residual life in the combs will maintain a constant selective pressure against "wild type" susceptible mites.
These facts suggest that long-term control of varroa with miticides will become more and more difficult with time (in case you hadn't noticed).
The "New" Antibiotic
Since I'm on the subject of resistance management, let's talk about tylosin. This antibiotic was registered for use against active cases of AFB. It was registered only after the AFB bacterium evolved resistance to the long-successful antibiotic Terramycin (oxytetracycline, or OTC). OTC has the desirable characteristic of degrading fairly rapidly in moist environments (as in a bee hive). Therefore, it fit the bill of allowing refuges of susceptible bacteria (and beneficial competing bacteria) to survive.
Tylosin, on the other hand, has a very long life in the hive-on the order of several months. That is why it is currently such an effective antibiotic against AFB-it just keeps killing and killing the bacteria. This persistence was noted in the process of its registration for bee hive use, so the label specifically prohibits its use as a prophylactic measure, or its application in sugar syrup.
Of course, many commercial beekeepers now routinely (and illegally, at least in my state) feed tylosin in sugar syrup as a prophylactic measure against AFB! It is a "box movers'" dream-no need to inspect for foulbrood, nor loss of AFB-tainted equipment-just treat ‘em all with tylosin. I strongly question this practice! We do not know the long-term effects of a persistent antibiotic upon symbiotic honey bee gut flora or those in the bee bread. Of even more concern is the imprudence of such practice-tylosin is an incredibly effective tool for the control of AFB. The routine use of it will predictably soon render it ineffective as tylosin-resistant bacteria evolve. Those misusing the product will ruin it for the rest of us! This is not a matter of "laughing with the sinners or crying with the saints"-it is rather a shortsighted folly.
First-World agriculture has reveled in the achievements of the Green Revolution and factory farms, the success of which unfortunately depend upon energy-gulping fertilizer and transportation, massive pesticide and herbicide use, dousing animals in "Concentrated Animal Feeding Operations" with antibiotics, and government subsidies. We've become infatuated with the beauty of our weapons* against pests, weeds, and diseases. Although this system has been highly effective for the short term, there are good arguments that it is unsustainable in the long run.
*Apologies to Leonard Cohen
Commercial beekeeping has become a microcosm of the larger agricultural system. Let me note that I make my living as part of that system-renting bees for pollination, and selling honey by the drum. I enjoy as well plentiful, and what appears to be "cheap," food (if one ignores the hidden costs). Be assured that I'm not criticizing the system nor the farmers or beekeepers who feed the nation. Neither am I disparaging the use of miticides and antibiotics-they are valuable and necessary tools. However, I feel that it may be wise to pay attention to the evolution of the larger system, as beekeeping will likely reflect similar changes and challenges.
Big Agriculture is moving toward fewer (and safer) pesticides and antibiotics, more biotechnical methods of pest control, such as crop rotation and interplanting, better breeding for pest and disease resistance, and better animal nutrition. The parallels with beekeeping are hard to ignore.
New Pesticides
The market for agricultural pesticides is huge, so there is a constantly evolving arsenal of new pest control products-this year look for imaginative new names like Belay, Endigo, Zeal, Movento, Synapse, and Coragen (all ®) (Roberson 2009). The good news is that the newer classes of insecticides are generally designed to be more environmentally friendly, which is good news for bees.
However, with the release of each new pesticide, beekeepers wonder if there will be unforeseen ill effects upon their bees. When colonies die for no apparent reason, it is easy to blame said losses on the unfamiliar new product.
This has certainly been the case for the neonicotinoids. The good news is that the systemic neonics are replacing the nasty organochlorines and organophosphates (WHO Class 1-"extremely hazardous"), and can be used in much smaller amounts, since they are applied directly to the seed prior to planting, rather than spread or sprayed over the soil or crops.
However, many beekeepers in Europe, and some in the U.S., feel strongly that neonics can cause detrimental effects to their colonies. Numerous field trials (by Bayer, government labs, and independent researchers) generally fail to support this supposition (the continuing reports in the press are generally recycled old research). There is no doubt that some bees are harmed by some neonic applications, but in general, monitored test colonies appear to thrive when placed adjacent to neonic-treated crops in which the chemical has been properly applied. Indeed, I've spoken to some large commercial beekeepers who profess their love for the neonics, as their use has reduced the typical historical kills by the older generation of pesticides.
This is certainly not the final word on the neonics-I'm sure that the labels will need to be modified as we find specific cases where their use (such as in potatoes followed by clover, in melons, when applied by chemigation, etc.) appears to be harming bees and other nontarget organisms.
Guttation "water"
O.K., by the time you read this article, you may have heard the buzz about "guttation droplets" and neonicotinoids in young corn (maize) plants. Dr. Vincenzo Girolami in Italy released a video last year of bees dying rapidly after drinking droplets of sap exuded by clothianidin-treated corn seedlings. The twitching deaths were gruesome to watch, and fired up justifiable emotional outrage in beekeepers. Had the culprit for colony losses finally been pegged?
Well, there's a bit more to the story. In the first place, the knowledge about systemic pesticides in guttation fluid (a natural phenomenon in young plants in the grass family) was well known. The whole reason for seed treatment is to make the sap of seedlings toxic to root- and leaf-eating insects. Then as the plant matures, the concentration of pesticide naturally decreases, plus guttation normally ceases.
Beekeepers have complained about bee losses at the time of sunflower or corn flowering-but this occurs months after guttation in the seedlings. But some beekeepers also complained about losses just after planting. These losses could be explained by contaminated dust from the seeds as they are planted (as in the well-publicized clothianidin kill in Germany last year, in which the pesticide was not glued properly to the seed). Or, as Dr. Girolami (2009) points out in his recent paper, perhaps bees might be poisoned by drinking guttation droplets. His laboratory studies indicate that the droplets can indeed be toxic, but alas, he did not perform any "real-life" field tests, and stated "it is still not possible to draw a judgment on a possible correlation between neonicotinoid translocation into guttation drops and CCD."
Luckily, others have performed such field tests. I've been able to preview Bayer-funded studies that were performed in corn fields this spring at six sites in Austria and France, under different climatic conditions (some specifically chosen to have access to water restricted, and little alternative attractive flora), and involving 38 fields and about 100 colonies. Guttation on the corn seedlings was commonly present during foraging hours.
The results were that bees were observed foraging only at the field margins, and "only very occasionally" were individual bees observed exhibiting symptoms of intoxication. I've looked at the graphs of the numbers of dead bees caught in hive traps or fallen on linen sheets placed before the hives-there didn't appear to be any significant effect of seed treatment compared to control colonies on untreated fields.
The researchers found that the placement of gravel-filled watering trays decreased bee foraging for guttation water. However, colony development for three months appeared to be identical (and normal) whether alternate water was provided or not.
Aha, you say, that research was funded by Bayer! I also found that the Swiss government independently performed their own tests (BLW 2008), in which they found that clothianidin indeed occurred at toxic levels in the droplets for about a month after sowing. Again, the toxic droplets appeared to be repellent to bees. The independent Swiss researchers found no mortality due to clothianidin of bees in colonies placed next to the fields during and after sowing, and observed no deterioration of the health of the colonies. They did suggest that it would be good beekeeping practice to provide clean water if such was not naturally available.
The above findings will likely apply to the U.S. However, we plant corn in huge expanses, and I wouldn't be the least surprised if bees in such areas might be poisoned if drought occurs during the first month of seedling growth, should no clean alternative water sources be available. Again, please note that potential poisoning from guttation droplets would be an entirely different phenomenon from poisoning from the much later tasseling of corn.
In any case, I hope that the neonicotinoid question is resolved soon. Meanwhile, there is another class of plant protection products that keeps coming up on my radar...
Fungicides
Although beekeepers have long cursed pesticides, fungicides have generally been assumed to be safe for bees. We've recently learned otherwise. Some fungicides are demonstrably toxic to bee larvae. Exposure of larvae to pollen containing Captan®, Ziram®, or iprodione led to 100 percent mortality (Alarcón 2009).
Fungicides may also have synergistic effects when combined with other pesticides, or miticides applied by the beekeeper, making either more toxic to the bees. This is a problem that we experience when our colonies are pollinating almond orchards-where fungicides are often sprayed on the bloom. Many almond pollinators (myself included) have had serious issues after certain fungicides (e.g., Rovral® or Pristine®) were sprayed, sometimes in the short term, sometimes killing brood weeks later (Mussen 2008). This is a serious concern to those producing queens from colonies returning from almond pollination.
A scary thing about fungicide contamination is that there may be a delayed effect-one may not notice problems until the bees dig back into stored pollen months after exposure! VanEngelsdorp (2009) coined the term "entombed pollen" to describe brick-red beebread sealed by the bees with a black capping, and often associated with the fungicide chlorothalonil (Bravo®). The authors state: "These results provide compelling evidence that entombed pollen indicates exposure to a risk factor that is detrimental to honey bee colony survival." However, they did not find it to be directly responsible for either significant brood mortality or CCD.
In a recent series in this Journal, Dr. Gloria DeGrandi-Hoffman, et al (2009) reviewed the literature on beneficial microbes in bee hives. These microbes are mainly bacteria and fungi. Bees gather pollen, add nectar, saliva, and microbe inoculant from their mouths, and pack it into cells to undergo a lactic acid fermentation, similar to the making of silage, sauerkraut, or yogurt. After the initial fermentation, which preserves the beebread with acid, beneficial fungi then continue to digest the pollen, apparently making it more nutritious to the bees.
So let's say that you were about to make cheese out of milk at home. Unless you take special care to make sure that the culture is properly inoculated with beneficial bacteria and fungi, you will end up with a putrid, and possibly toxic, product (due to the bacterial and fungal toxins produced by unwanted microbes).
When bees ferment pollen into beebread, they count on the right microbes to do the job. Honey bees have a long evolutionary involvement with beneficial symbiotic bacteria and fungi, and several of them appear to be associated with the health and nutrition of colonies. When a fungicide (or possibly an antibiotic) is inadvertently added to the pollen, we simply do not know whether the "normal" fermentation process will take place, or whether the chemicals will allow toxin-producing microbes to thrive. The entombment of pollen may simply be the way that bees deal with beebread "gone bad" so that the nurse bees don't suffer from "food poisoning."
Now I've saved what most interests me for last. Honey bees require sterols as essential dietary nutrients (meaning that they can't create them themselves, similar to vitamins). The critical bee sterol is 24-methylenecholesterol (I'll abbreviate it as 24-mCh). Luckily, this is often the main sterol found in pollen (Svoboda 1983). There is also a sterol precursor to 24-mCh called sitosterol, but Herbert ( 1980), in feeding trials of synthetic diets, found that bees were apparently unable to convert sitosterol (or other sterols) to 24-mCh.
Without 24-mCh in the diet, nurse bees apparently "steal" it from their own body reserves to produce the jelly which they then feed to the queen and larvae. Herbert (1980) found that in diets lacking 24-mCh, broodrearing is restricted, and drops off precipitously after two brood cycles (although they can use plain cholesterol in the short term).
Note that this drop off after two brood cycles is typical of pollen "substitutes," including that used in a recent greenhouse trial at the Tucson lab. The colonies in that trial quickly recovered when they were given a small amount of beebread scraped from combs of free-flying colonies. No one has determined what the critical ingredient supplied by the beebread was.
Note also that due to bee colony population dynamics, a major drop in brood rearing wouldn't be noticed by the beekeeper (unless he's inspecting the broodnest) until about six weeks later, when the missing brood would have become foragers. A colony can quickly recover the field force if there is a lot of sealed brood, but not if there was a break in brood rearing several weeks previously.
Now here's the part that catches my attention. Loper (1980) found that almond pollen, hand brushed from the blossoms, contains both sitosterol and 24-mCh, but that in the same pollen, trapped from bees' legs in pollen traps that were emptied hourly, the sitosterol content dropped sharply (154 to 38 mg/kg), whereas the 24-mCh content rose substantially (428 to 544 mg/kg)!
So here's my question: If bees are unable to convert dietary sitosterol into 24-mCh in cage trials lasting weeks, how the heck do they manage to do it in an hour in the pollen loads on their legs?
The answer may come from Gilliam (1997): "Our studies of floral and corbicular [collected on bees' legs] pollen ...demonstrated that pollen from a flower changes microbiologically and biochemically as soon as the honey bee collects it." She found that bacteria and yeasts were very quickly replaced by molds (fungi). Certain fungi (such as Mortierella) are notable for producing 24-mCh (although Gilliam did not identify this genus in bees).
So, questions that I have for researchers are, (1) what is the mechanism for the conversion of sterols in the corbicular pollen, (2) do agricultural fungicides stop the process, and (3) since 24-mCh is critical in the royal jelly to produce queens, how are fungicides used in almonds affecting the queens produced afterwards? I'm very curious as to how fungicides, even those that aren't overtly toxic to bees, are affecting the nutrition, health, and development of queens in our colonies.
Wrap Up
Modern agriculture has become heavily dependent upon pesticide use. Unfortunately, the pests are catching up. All forms of agriculture, including beekeeping, will be forced to move to smarter management, with fewer, and less hazardous, pest control products. Proactive beekeepers are currently shifting to such practices as IPM and natural treatments.
The incredibly effective antibiotic tylosin is unfortunately being misused, which will likely lead to resistant AFB bacteria, and possibly to unexpected problems with colony biotic balance.
Agriculture is generally moving toward more environmentally-friendly pesticides. The neonicotinoids appear to be one of these. However, some beekeepers feel that the neonics are causing serious problems. There is currently a lack of supporting scientific evidence in most cases (with noted exceptions), but research continues.
Fungicides, which have been generally considered to be harmless to bees, are being found to be anything but! Researchers are reinvigorating investigation of the roles that microflora play in colony health and nutrition, and the effects that fungicides and antibiotics may have when the microfloral "balance" is disrupted
Acknowledgements
As always, I am deeply indebted to my collaborator Peter Loring Borst, without whom I could not conduct the research necessary to document these articles.
References
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Cover Story November 2009
(excerpt)
Apicultural Research--"Nozevit patties" Treatment of Honey Bee (Apis mellifera) for the Control of Nosema ceranae Disease
ABSTRACT
Nosema disease affects adult honey bees and due to its mostly inconspicuous signs and the need for eradication by exchange of frames with brood from a disinfected hive and often use of new wax, beekeepers devote insufficient attention or often neglect the disease. Also, there is a problem of controlling nosemosis, especially caused with N. ceranae because of its asymptomatic duration and prohibition of using antibiotics in the treatment of apian diseases in the European Union, as well as in Croatian regulations. We have predicted great results for use of protein pollen patties with "Nozevit" herbal preparation, as a feed supplement for bee colonies, where it can have an effect on brood rearing (colony strength) and at the same time reduce the number of Nosema ceranae spores. The aim of this study was to assess the effectiveness of the "Nozevit" phyto-pharmacological preparation in protein/pollen substitute patties for treatment of nosema disease in comparison with patties without "Nozevit" and sugar solution in a similar control group.
INTRODUCTION
Nosema disease is a parasitic disease of adult honey bees (Apis mellifera) caused by two described species of microsporidia, Nosema apis (Zander, 1909) and Nosema ceranae (Fries et al., 1996), which in adverse living conditions forms spores. This disease affects adult bees and due to its inconspicuous signs and the need for eradication by exchange of frames with brood from a disinfected hive and often use of new wax, beekeepers devote insufficient attention or often neglect the disease. Honey bees afflicted with nosemosis start to forage earlier (Fries, 1995), while pathological changes of their mid-gut epithelial cells, as well as digestive and metabolic disorders (Hassanein, 1951), cause malnutrition (Muresan et al., 1975), lack of population build up and consequentially decrease of population size of honey bee colonies (Malone et al., 1995) leading to premature deaths (Morse and Shimanuki, 1990).
New Nosema ceranae is highly pathogenic and there are usually no visible symptoms of diarrhea or adult bee deaths and there is total lack of seasonality in the diagnosis (Martin - Hernandez et al., 2007), and little is known about pathogenicity (Oldroyd, 2007). Infections with N. ceranae induce a nutritional stress, suppression of the bee's immune functions and cause changes in behavior where infected bees tend to forage at cooler temperatures (Mayak, 2009). Bees infected with new parasitic pathogen starve to death due to lack of digestive function and this leads to increased number of honey bee colony losses, destruction of plant communities and low production in the same areas which consequently cause significant loss of beekeeper's income (Stefanidou et al., 2003).
There is a problem of controlling nosemosis, especially caused with N. ceranae because of its asymptomatic duration (Martin - Hernandez, 2007) and prohibition of using antibiotics in the treatment of apian diseases in EU, as well as in Croatian regulations. Recently, we have published results of experimental nosema disease treatment with the natural phyto-pharmacological preparation "Nozevit" in sugar solution (Tlak Gajger et al., 2009) which shows that a large number of spores were considerably reduced upon preventive (70.91%) and curative (78.37%) treatment. But, bees need more than just carbohydrates from honey or sugar syrup to survive, especially proteins. The most significant source of proteins in nutrition of honey bee colonies is pollen or pollen substitutes. Proteins are mainly needed for reproduction and brood rearing (Herbert, 1999); to produce protein-rich brood food to feed larvae, but also the queen needs a steady supply with protein-rich royal jelly, to have enough protein to lay up to 2000+ eggs a day. Also, there are a lot of reasons for additionally feeding bees with pollen substitutes like: early spring build up before appearance of first vegetation; build up in preparation for pollination; to force building in preparation for a strong nectar flow, to encourage early drone rearing; to maintain drone and brood rearing through a strong dearth (Day et al., 1990), and ensure wintering survival. Less brood rearing eventually reduces the number of adult bees, including foragers, and may consequently affect pollination efficiency and honey yields (Herbert, 1999) and if we draw a comparison with nosemosis, it has the same consequences. So, the pollen patties composition is important both for its nutritional value and for its effect on how readily bees consume it (Keller et al., 2005a). Because of that we have predicted great results for use of pollen patties with "Nozevit" as a feed supplement for bee colonies in early spring and in autumn, where it can have an effect on brood rearing (colony strength) and at the same time reduce the number of Nosema spores, thereby preventing the spread of disease inside the colony. The aim of this study was to assess the effectiveness of the "Nozevit" phyto-pharmacological preparation added to "Brood Builder" - protein/pollen substitute patties for treatment of nosema disease in comparison with patties without "Nozevit", and sugar solution in a similar control group. Also, we have checked the strength (number of populated and brood frames) of treated and untreated honey bee colonies during the clinical examination in the field conditions.