SUSTAINABLE SOLUTIONS TO PROBLEMS AFFECTING BEE HEALTH

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0223588
• Multistate No.: NC-_OLD1173
• Project Start Date: Oct 1, 2010
• Project End Date: Sep 30, 2013
• Program Code: [(N/A)]- (N/A)

Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853

Performing Department
Entomology

Non Technical Summary
The honey bee plays a critical role in most cropping systems that depend on insects for pollination, contributing $14.6 billion/yr in added-value to US agricultural output, including $300 million to growers in NY. In addition to contributing to a sustainable supply of healthy and affordable fruits and vegetables, beekeeping is a valuable source of income in rural communities. Honey bees are under severe stress, with hundreds of thousands of colonies killed each year by multiple factors, including parasites, pathogens, pesticides, and a recent syndrome known as Colony Collapse Disorder (CCD). These losses put beekeepers, growers and their employees at risk of losing a significant portion of their income, and puts the general public at risk of losing a critical source of many of the most healthy and nutritious foods in their diet. Historically, migratory beekeepers have recovered from large losses by moving to a southern state in the fall where they build back their numbers for the following season. With CCD, beekeepers cannot restore colony numbers because colonies taken south continue to die over the winter. Therefore, the number of colonies available for pollination the following year is below normal, replacement costs are high, and these cost are passed on to growers and consumers. Bees rely on pollen and nectar as their sole sources of protein and carbohydrates. One high priority hypothesis identified by both researchers and stakeholders explains recent losses as the consequence of an impoverished diet encountered in large monocultures where bees are employed to pollinate crops. According to this hypothesis, as field/orchard size increases, the diversity of pollen types (and amino acids) available decreases, and this results in a diet lacking essential nutrients, and that has negative impact on normal worker development and lifespan, as well as on the ability to generate an adequate immune response to parasites and pathogens. While plausible, the underlying assumption, that large monocultures offer inadequate diets, has not been demonstrated. Honey bees forage over an area as large as 45,000 acres and may collect a diverse diet despite being placed in these environments. In response to the recent losses, many commercial beekeepers are using various supplemental feeding regimes in an attempt to maintain colony health; however, there are no data demonstrating that these practices have the desired effect nor is there any data demonstrating the effect of these treatments on pollinator efficiency. This project will investigate the effects of managed ecosystems, especially available nutritional resources and supplements, on colony health and the efficiency of pollination in five major cropping systems. It will also evaluate the role of pesticides, Varroa destructor and Nosema ceranae on these same variables. Each of these factors is identified as high priority by academic and industry organizations.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
306	3010	1130	100%

Knowledge Area
306 - Environmental Stress in Animals;

Subject Of Investigation
3010 - Honey bees;

Field Of Science
1130 - Entomology and acarology;

Keywords

honey bees

pollination

colony collapse disorder

ccd

pollination efficiency

colony health

nutrition

amino acids

supplemental feeding

brood pheromone

Goals / Objectives
To determine the effects of pesticides and other environmental chemicals on honey bee colony health. To determine how environmental factors, including nutrition and management practices affect honey bee colony health. To determine the effects of interactions among various factors affecting honey bee colony health. To coordinate research and extension efforts related to bee colony health.

Project Methods
1. Four small fields/orchards (≤20 acres) and four large fields (≥250 acres, depending on crop) will be identified for five major cropping systems. Four colonies cited near the center of each field and four along the perimeter will be identified and used as experimental units. Colony entrances will be screened for 20 min, and returning foragers will be collected using a DC Insect Vac. Sample collection tubes will be placed in CO2 to narcotize bees and then on dry ice to kill them. Bees will be sorted according to the presence or absence of pollen and then by visual determination of pollen type. Pollen type will be confirmed using standard palynological methods (acetolysis and microscopic examination with pollen types identified using existing libraries and voucher specimens collected in the field). Diversity and abundance of pollen types and a pollen diversity index will be calculated for each colony. 2. The total number of foragers returning during the sampling period, the proportion of foragers returning with pollen and the proportion of pollen foragers bearing pollen from the target crop will be calculated from the data in OBJ. 1. 3. A second set of pollen samples will be collected from honey bee colonies in each field using the protocol described above. The pollen will be removed from the bees' legs, pooled by field (total of 8 pooled samples per crop), frozen in liquid nitrogen and returned to the lab for protein extraction and analysis. Protein identification and amino acid composition will be determined using the isobaric tag relative and absolute protein quantitation (iTRAQ) technique followed by typical multiple dimensional liquid chromatography in the shotgun. All iTRAQ-based proteomic analyses will be conducted at the Proteomics and Mass Spectrometry Facility of Cornell Biotechnology Center, Cornell University. 4. Beekeepers feed pollen substitute to provide protein and maintain colony health during pollination. Pollen substitutes decrease pollen collection while brood pheromone and sugar syrup increase pollen collection. I will evaluate the effects of all eight combinations of these substances on colony health, the diversity/abundance of pollen types collected by colonies and the focus of foragers on the target crop. Each of the eight treatment combinations will be replicated on 12 colonies in the 4 large fields of each crop where the environment is more likely to have an adverse effect. Changes in colony health will be assessed by counting combs with bees and brood in each colony immediately before treatment and again just prior to removing bees from the fields. All other metrics will be assessed using methods outlined in #1 and 2. Levels of Nosema ceranae and Varroa destructor will be quantified in all experimental colonies. Pollen samples will be collected for use in a broad pesticide screen (> 100 compounds). Weather conditions (ambient temperature, relative humidity and total solar radiation) will be measured in 4 fields each year using HOBO Data Loggers.

Progress 10/01/10 to 09/30/13

Outputs
Target Audience: PI retired August 16, 2013, no final report information will be entered. Changes/Problems: PI retired August 16, 2013, no final report information will be entered. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? PI retired August 16, 2013, no final report information will be entered.

Publications

Progress 10/01/11 to 09/30/12

Outputs
OUTPUTS: 1. One possible cause for the recent losses of honey bee colonies is the recently discovered parasitic fungus Nosema ceranae. An accurate assessment of the level of nosema infection is key to evaluating its effects on colonies and the effects of treatments designed to control this parasite. The current method for assessing infection levels is based on an estimate of the average number of spores per bee in a pooled sample of 30-60 bees. This method has a major shortcoming because the average number of spores per bee may not be correlated with the proportion of bees in a sample that are actually infected or the degree of similarity in the level of infection of individual bees in the sample. The latter measure of infection is the most relevant measure but also the most laborious to obtain because it requires obtaining estimates for each individual bee in a sample. Based on 97 samples of 30 bees each, I found a significant correlation between the average number of spores per bee and both of the other two measures, although the correlation only accounted for about half of the variation. 2. To assess the effects of supplemental feeding on colony health and pollen collecting behavior of honey bee colonies while on location for pollination, eight colonies of honey bees were placed in each of three fields of organic butternut squash near Seneca Castle, NY (24 in all). Samples of workers were collected to allow for estimating varroa mite (brood nest bees) and nosema (foragers) levels in each colony immediately prior to placement and again 3-4 weeks later just prior to removal at the end of bloom. Estimates of worker populations and capped brood area were obtained at the same times. Colonies were weighed at the start of the project and again at the end to assess overall weight gain, another measure of colony health. Colonies in each field were assigned to one of four treatment groups: control, supplemental sugar syrup, supplemental protein, and supplemental sugar syrup and protein. Forager samples were collected in the AM from each colony once a week. Data is being processed. 3. Two large supporting databases have been completed. One (The Value of Honey Bees as Pollinators of U.S. Crops) allows researchers easy access to the production and inflation-adjusted values of insect pollinated crops from 1992 through 2009. A second (U.S. Honey Production) provides the same data for honey during the same period. Currently, both databases are being updated to include data through 2012. These databases are supportive of the need to conduct research on the health of honey bee colonies. PARTICIPANTS: Rick Pedersen. Pedersen Farms Seneca Castle, NY. Provided fields of organic butternut squash for placing colonies for evaluation. Emily Satinsky Cornell undergraduate student employee. Provided support for collecting and processing pollen samples, treating bee hives and quantifying colony health (nosema levels, brood levels, worker populations) Erin Loughlin Cornell Undergraduate student employee. Provided support for collecting and processing pollen samples, treating bee hives and quantifying colony health (nosema levels, brood levels, worker populations) Shiliu Wang Cornell Undergraduate student employee. Provided support for collecting and processing pollen samples, treating bee hives and quantifying colony health (nosema levels, brood levels, worker populations) Peter Murphy Cornell Undergraduate student employee. Provided support for collecting and processing pollen samples, treating bee hives and quantifying colony health (nosema levels, brood levels, worker populations) TARGET AUDIENCES: There are two audiences interested in the health of honey bee colonies. One consists of beekeepers providing colonies for pollination. The second consists of growers who depend on honey bees for pollination. Beekeepers are educated on the best management practices for controlling parasitic mites and other honey bee pathogens and parasites though a workshop series on practical beekeeping. The following workshops were held: Master Beekeeper Apprentice Level - Spring Course 2012 (2 days). Dyce Laboratory for Honey Bee Studies, Ithaca, NY, May 5&6 (consists of 16, 45 min presentations (12 hr) and 4 hr of activities for a total of 16 hr * 24 attending = 384 contact hours) Master Beekeeper Apprentice Level - Spring Course 2012 (2 days). Dyce Laboratory for Honey Bee Studies, Ithaca, NY, May 12&13 (consists of 16, 45 min presentations (12 hr) and 4 hr of activities for a total of 16 hr * 24 attending = 384 contact hours) Master Beekeeper Apprentice Level - Fall Course 2012(1 day). Ithaca, NY, Tompkins County. Aug. 11. Dyce Laboratory for Honey Bee Studies, (consists of 8, 45 min presentations (6 hr) and 2 hr of activities for a total of 8 hr * 24 attending = 192 contact hours) Master Beekeeper Apprentice Level - Fall Course 2012(1 day). Ithaca, NY, Tompkins County. Aug. 18. Dyce Laboratory for Honey Bee Studies, (consists of 8, 45 min presentations (6 hr) and 2 hr of activities for a total of 8 hr * 24 attending = 192 contact hours) Growers interests will be addressed in the final year of the project with a manual on evaluating honey bee colonies that are rented for pollination. PROJECT MODIFICATIONS: The present method of collecting pollen samples involves collecting foragers returning to the nest during a 10-20 minute period. The process is laborious and it can be difficult to process samples with certain types of pollen, notably pollen from cucurbits which is very light and fluffy and prone to falling off the bees legs. Future collections will be based on pollen stored in a series of combs placed in the brood nest of colonies while on location. Combs will be empty when introduced and pollen stored in cells will be sampled when combs are removed.

Impacts
1. Although unbiased, current methods used for estimating nosema levels contain significant experimental error. This means that the number of replicates used in any experiment needs to be higher than one might normally anticipate. The exact effects of this error on sample size is currently being investigated. 2. Recommendations on supplemental feeding of colonies while on site for pollination cannot be made until the past season's data are analysed.

Publications

• Calderone NW (2012) Insect Pollinated Crops, Insect Pollinators and US Agriculture: Trend Analysis of Aggregate Data for the Period 1992 through 2009. PLoS ONE 7(5): e37235. doi:10.1371/journal.pone.0037235
• Calderone NW (2012) The contribution of insect pollinators to US agriculture in 2010. Bee Culture Dec. 2012, pp 32-38

Progress 10/01/10 to 09/30/11

Outputs
OUTPUTS: We conducted a series of studies to examine the effects of parasites, nutrition and pesticides on the health of individual worker honey bees. Forty cages, each containing 40 newly-emerged bees from 5 unrelated sources (8 cages/source) were established and maintained in an incubator at 32C and 50% RH. Bees received distilled, 18 mega-ohm water ad libitum and sucrose syrup (1:1 w:w). Four cages from each source received a daily feeding of pollen substitute while the other half did not. Two cages receiving substitute and two cages that did not receive substitute received 25K Nosema ceranae spores/bee/day in the sucrose syrup for 8 days. After 20 days, 1 cage from each of the 4 treatment groups received sucrose syrup with pesticide; the other half received only sucrose syrup. Therefore, 1 cage from each source was assigned to each of 8 treatment groups. The entire experiment was replicated using 40 additional cages of bees obtained from 8 unrelated sources. Dead bees were removed from cages each day, and individual spore counts were obtained for each dead bee. At the end of the experiment, up to 10 surviving bees were sampled from each cage, and spore counts were obtained for each bee. The proportion of bees dying immediately prior to the application of pesticide (PRE) and the proportion of surviving bees that died the day following the application of the pesticide (POST) were determined. Data were analyzed with a mixed model with treatment as a fixed effect and trial and source of bees within trial as random effects. PRE mortality was 0.09 +- 0.0795 for bees receiving protein (PROT), 0.15 +- 0.0795 for control bees (CON), and 0.26 +- 0.0795 for those receiving both protein and nosema (NPROT), and 0.33 +- 0.0795 for those receiving only nosema (NOS). PRE mortality for CON and PROT were not significantly different, but mortality in both groups was significantly less than that in the NOS group and in the NPROT group. Mortality in the NPROT and NOS groups did not differ significantly from each other. Nosema increased mortality, but mortality was not affected by the addition of protein to the diet. POST mortality was lowest in the PROT (0.02 +/- 0.0428), NPROT (0.07 +- 0.0428 and CON (0.06 +- 0.0428) groups and highest in the groups receiving nosema and pesticide (NPEST) (0.46 +- 0.0428) and nosema, pesticide and protein (NPP) (0.32 +- 0.0428). Mortality was not greater in the pesticide (PEST) or nosema (NOS) groups compared to the control (CON) group; but mortality in the NPEST, pesticide plus protein (PP) and NPP groups was significantly greater than in the CON group. Neither nosema nor pesticide treatment alone increased mortality relative to the CON group (P < 0.10); however, the combination did result in greater mortality (P < 0.05). The addition of protein to the diet did not protect bees from the effects of the pesticide. Spore counts were significantly lower (P LE 0.0001) in bees dying before the application of pesticide (215.97) than in bees surviving until the end of the experiment (538.06). While this is expected, it raises the question about the effects of nosema on lifespan. PARTICIPANTS: Pei-Chun Wu, a graduate student in my lab, participated in this project as part of her thesis work but was not compensated from project funds. Eric Chang, an undergraduate student worked on the project during the summer. Xiana Garcia Freire, an undergraduate student, worked on the project during the summer. Both undergraduates received wages from the project funds. Xiana Garcia Freire conducted one of the preliminary studies as part of her undergraduate honors thesis. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Originally, the project was going to evaluate the effects of supplementary feeding of sugar syrup and pollen substitute on the effects of pesticides and parasites in field colonies on site for vegetable pollination. Thirty-two packages of honey bees were ordered for delivery in mid-May; however, they were not sent by the supplier until mid-June. Consequently, they did not have time to develop into colonies with sufficient strength to use for the project by the time vegetable pollination was underway in mid-July. It was decided to test the same hypotheses using cages of bees in a laboratory setting.

Impacts
A preliminary study not reported above evaluated four commercial pollen substitutes in order that the most palatable substitute could be used in the larger experiment. Total mortality did not differ significantly among the four commercial pollen substitute treatments or the control (P < 0.41) or among the five sources of bees used. Bees consumed 0.70 g per cage of 40 bees of the least palatable substitute compared to 2.1 g per cage of the most palatable, a difference of 200%. These results demonstrate that the formulation of pollen substitutes is critical as there can be significant affects on palatability; beekeepers should select a substitute that provides adequate nutrition while still remaining palatable. A second preliminary study found that the addition of a pollen substitute to the diet resulted in lower mortality after exposure to a pesticide. This preliminary study was done with young, nurse age bees, and that may account for the differences between that study and the larger project in which forager age bees were exposed to the pesticide.

Publications

• No publications reported this period