PESTICIDE AND PATHOGEN SCREENING OF THE ALTERNATIVE POLLINATOR OSMIA CORNIFRONS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0230813
• Project No.: NYC-139415
• Project Start Date: Oct 1, 2012
• Project End Date: Sep 30, 2015

Project Director
Danforth, BR, N..

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

Performing Department
Entomology

Non Technical Summary
Declines in honey bee populations across the United States over the past 50 years, and reports of dramatic honey bee losses caused by colony collapse disorder (CCD) over the past 5 years, has raised concerns about the long-term advisability of reliance on a sole, non-native crop pollinator (the honey bee). Alternative crop pollinators exist, including wild, native bees occurring naturally in the vicinity of agricultural production as well as managed, alternative pollinators, such as Osmia (mason bees) and Megachile (leaf-cutter bees). In eastern apple orchards there are over 100 native bee species that are likely contributing substantially to apple pollination. In addition, managed pollinators, such as mason bees are known to be excellent apple pollinators based on studies in the western US, Europe and Japan. Our project will focus on one such managed pollinator, Osmia cornifrons (the horn-faced bee). The horn-faced bee is common in the eastern US and populations can be managed and experimentally manipulated using artificial, trap-nests. We will use trap-nests to study two potential threats to long-term viability of horn-faced bee populations in apple orchards: (1) pesticides and (2) fungal pathogens. We will collect and analyze pollen provision masses from trap-nests of the horn-faced bee using standard analytical methods (gas and liquid chromatography) in order to detect the composition and level of pesticides in provision masses. We will screen broadly for insecticides, herbicides, and fungicides, which are all used heavily in apple orchards in the eastern US. We will also compare the levels of pesticides among orchards and we will focus on the impact of orchard management (conventional, IPM, and organic) on pesticide levels in pollen provision masses. Second, we will screen larval and adult bees for fungal pathogens widely implicated in honey bee and bumble bee population declines: Nosema. We will use standard laboratory techniques (PCR amplification of Nosema DNA and DNA sequencing of PCR products) to detect pathogen levels as well as pathogen identity. These results will help us understand whether fungal pathogens pose a threat to long-term management of mason bees in apple orchards. Finally, we will examine if there is an interaction between pesticide levels and pathogen levels. One might expect such an interaction because pesticides have been shown to depress immune function in a variety of organisms. Our project will be the first to directly measure pesticide levels in pollen provision masses and will be the first to attempt to identify fungal pathogens of managed mason bees. Long-term, sustainable apple production may require that apple growers manage their orchards in ways that support wild bee pollinators, and this project will be first step in identifying the best management practices to achieve this goal.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
711	1110	1130	25%
711	3090	1130	75%

Knowledge Area
711 - Ensure Food Products Free of Harmful Chemicals, Including Residues from Agricultural and Other Sources;

Subject Of Investigation
1110 - Apple; 3090 - Other Pollinators;

Field Of Science
1130 - Entomology and acarology;

Keywords

pollination

pesticides

pathogens

apple

bees

conservation

Goals / Objectives
Our project will focus on two main objectives to investigate the effects of pesticides and pathogens on a wild pollinator species in commercial apple orchards. First, we will screen pollen provisions collected by female Osmia cornifrons in commercial apple orchards for pesticide residues. We will answer the following questions: (1) Are detectible pesticide residues present in the pollen provisions of Osmia cornifrons (2) Do management practices (i.e. organic, integrated fruit management, or conventional) effect the amount or type of pesticide we detect in pollen provisions (3) Is there evidence of pesticide-related mortality in Osmia nests placed in apple orchards Our second objective is to screen adult Osmia cornifrons bees for pathogens associated with bee population declines in other species. For this objective we will answer the following questions: (1) Do species of Nosema, a microsporian fungus known to be pathogenic in other bee species, infect O. cornifrons (2) Does the level of Nosema infection vary widely among orchards/sites (3) Is the level of Nosema infection related to aspects of orchard management (e.g., pesticide use, presence/absence of honey bees, etc.) We will use the answers to these questions to create educational materials for orchard growers on the effects of pesticide residues and pathogens on alternative pollinator species. We will involve undergraduate students, graduate students, and extension professionals throughout the duration of the project. Alternative managed pollinators, such as Osmia cornifrons, have the potential to improve both the profitability and sustainability of New York apple orchards. This project will be among the first to extend the analytical and molecular techniques developed to look at the effects of pesticides and pathogens on the health of honey bees to wild, non-Apis bees. We will be the first to screen pollen provisions of Osmia species for pesticides and the first to look for Nosema in Osmia (and other wild bee) populations. This project will produce informational materials on the effect of various pesticides on solitary bees and suggest management plans to minimize risk. Our project will directly benefit apple growers and the over 17,000 people who work in the handling, distribution, marketing, processing and shipping of apples, apple consumers, and the natural environment of New York State. We will involve graduate and undergraduate students in the research, thereby exposing students to the importance of insect pollination in their daily lives. By supporting alternative bee pollinators, we will reduce reliance on imported honey bees. As declining populations of honey bees are reported throughout the eastern US, it is essential that we identify the management practices which have the least detrimental impact on native and wild pollinators.

Project Methods
We will establish wild Osmia cornifrons populations at 12 apple orchards in the area surrounding Ithaca and Geneva. We will select farms with a variety of management practices (organic, integrated pest management, conventional) and honey bee abundances. Data on each farm's management and honey bee abundance has been collected by our lab for previous studies of native bee diversity in apple orchards. After bee foraging activity ends each year we will collect pollen provisions to analyze for pesticide residues and adult bees for DNA extraction and presence of Nosema infection. Pesticide residue screening: Osmia conifrons females over-winter as adults and emerge in early spring to mate. After mating, female bees begin the process of laying eggs and gathering pollen to provision each egg. Female bees are active for approximately six weeks, a period which overlaps with apple bloom so that any pesticides sprayed in apple orchards before, during, and after bloom may be present in pollen provisions. As soon as bee foraging activities finish we will collect a subset of nests from all sites. Pollen provisions will be removed and stored -80C for further analysis. Spray records for the period of bee activity will be provided by growers at each farm and will allow us to select which pesticides to screen. Based on pilot study conducted in May, 2011, we expect this list to include the fungicide captan along with the insecticides indoxacarb, difenoconazole, and abamectin. Multiresidue pesticide analysis will be performed by the Connecticut Agricultural Experiment Station's Department of Analytical Chemistry (USDA-CAES) in New Haven, CT and will include both gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. Pathogen screening: Thirty adult bees from each site will be collected throughout the active foraging period and stored for pathogen screening. We will use polymerase chain reaction (PCR) and Sanger sequencing of PCR amplicons to determine if species of the microsporidial fungus Nosema are present in any O. cornifrons adults collected at our sites. PCR primers have been developed for Nosema spp. and a number of studies have successfully used this technique to detect Nosema in other bee species.

Progress 10/01/12 to 09/30/15

Outputs
Target Audience:Local Farmers (especially apple farmers) NY State residents The scientific community Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Post-doctoral, Graduate and undergraduate training: Our project involved significant post-doctoral and student training. Mary Centrella, a graduate student in the department of Entomology, took a lead role in the field trap-nesting studies and in the analysis of the historical (museum) data. Mary worked closely with a temporary technician (Amanda Stephens) to conduct the field experiments. Postdoc Laura Russo contributed to the project during the field season. Undergraduate students (including Nolan Amon, and Graham Montgomery) helped with both field and laboratory studies. These students gained considerable expertise in bee biology, taxonomy, computational biology, and pollination biology. How have the results been disseminated to communities of interest?We presented our results to grower groups in a variety of ways, primarily via extension presentations at local, regional, andstate-wide meetings. Extension talks: Orchard Bee Association Conference, Kayesville, UT, Sept. 2013, "Distributions of Osmia cornifrons and Osmia lignaria",: 45 minute oral presentation Orchard Bee Association Public Exposition, Kayesville, UT, Sept. 2013, "Mason Bees as Ideal Pollinators", 2014: 15 minute oral presentation Fruit EXPO, Syracuse, NY, Jan. 22, 2014, "Honeybees, CCD, and the importance of wild pollinators for orchard pollination" NY State IPM advisory council meeting, Syracuse, NY, Feb. 25, 2014, "Honeybees, CCD, and the importance of wild pollinators for orchard pollination" Outreach talk at the Ecovillage at Ithaca (February 2014). "Honeybees, CCD, and the importance of wild bees for orchard pollination." Hudson Valley Commercial Tree Fruit School, Kingston, NY, Feb. 10-11, 2015, "The important role of wild bees in NY apple pollination" Science Cabaret, Ithaca, NY, April 21, 2015. "Colony collapse disorder and how the wild bees are doing to save us" What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? a) Major activities completed: 1. Pesticide detection - We placed mason bee "trap nests" in 17 apple orchards in the Finger Lakes region of New York in Spring 2013, 2014, and 2015. Mason bee populations were seeded with overwintering bees from populations in Ithaca, NY in late April. Mason bees were allowed to establish nests and initiate foraging. Recently completed nests were collected, brought back to the lab, and the pollen/nectar provision masses were removed and analyzed for pesticides. We detected a total of 29 agricultural pesticides, including insecticides, fungicides, herbicides, antimicrobial compounds, organophosphates, and neonicotinoid insecticides. We combined our data on pesticide levels with toxicity data from honey bees to calculate the "hazard quotient" (HQ), a measure of overall toxicity of each pesticide to bees. Some pesticides were detected at very high levels relative to the LD50 for honey bees, including Clothianidin Phosmet, Imidacloprid, Indoxacarb, and Spinosad. 2. Pathogen screening - We screened overwintering adult Osmia cornifrons for pathogens, including viruses, bacteria, and fungi that have been reported previously in honey bees. We used PCR to amplify pathogens from bees and Sanger sequencing to to identify the species of pathogens detected. Sequences were compared to existing databases to determine whether the infecting strain shared identity with known honey bee strains or is novel to mason bees. Ascosphaera spp., a fungal pathogen found in social and solitary bees and the causative agent of chalkbrood, was detected in nearly 40% of the bees we screened. Likewise, fungi in the genus Aspergillus (21%), the causative agent of stonebrood in honeybees, and bacteria in the genus Paenibacillus (7.6%) were also relatively common across sites. Based on phylogenetic analysis of sequenced pathogens, we determined that O. cornifrons are infected with a diverse assemblage of Ascosphaera species, one of which appears to have been introduced from Japan through transcontinental movement of bees for agricultural pollination. 3. Bee databasing - There are two species of Osmia that are most significantly utilized in agricultural settings in the US: O. lignaria, an endemic species, and O. cornifrons, intentionally introduced in 1969. Because these species nest in similar structures and have similar foraging ranges, we are interested in whether the introduced species has displaced the native species at a landscape scale. Over the course of the project, we have been working on mapping Osmia distributions for the past year for both Osmia cornifrons and Osmia lignaria. We have analyzed data from 3243 specimens of bees gathered from 19 insect collections spanning a timeframe from 1850 to 2014. We have graphed abundance trends and mapped distributions for both species. We plan to add at least 9 more collections to this dataset and will analyze data by breaking it into grids per decade to quantify both spatial and temporal changes. Once we have this baseline data, we will be able to compare it to the land-use, temperature, moisture, and crop type changes, using similar grids modified from GIS layer data. To account for sampling error inherent in museum data, we will: a) assess the relative abundance of each species by comparing the two species, with the null hypothesis being that they will have equal spatial and temporal distributions and b) eliminate biases by removing either collectors and/or collections from the data set to see if the results are altered. b) Significant results achieved (major findings, developments, conclusions): 1. Pesticide detection - We detected a surprising diversity of pesticides, many of which are not sprayed on a regular basis on apple orchards. Nearly one half of the pesticides we detected were not sprayed in apple orchards in which we established our nesting sites. These pesticides were colleted by the bees either from neighboring agricultural areas, or they are systemically expressed in plant tissues, such as pollen and nectar. We are following up on this idea and analyzing spray records from our collaborating apple growers to see if the neonicotinoid pesticides, which are known to be expressed systematically and to persist for long periods of time (i.e., years) in the environment. The table below provides a complete list of pesticides detected in surveys conducted over the three years of the grant. Pesticide Pesticide class Acetamiprid NEONIC PESTICIDE Atrazine HERBICIDE Azinphos-methyl ORGANOPHOSPHATE Carbaryl (Sevin) INSECTICIDE Carbendazim FUNGICIDE Chlorpyrifos ORGANOPHOSPHATE Clothianidin NEONIC PESTICIDE Cyprodinil FUNGICIDE Difenconazole FUNGICIDE Dodine ANTIMICROBIAL Fenbuconazole FUNGICIDE Fipronil INSECTICIDE Flumioxazin HERBICIDE Imidacloprid, 5-Hydroxy NEONIC PESTICIDE Indoxacarb INSECTICIDE Iprodione FUNGICIDE Metolachlor HERBICIDE Myclobutanil FUNGICIDE Oxadiazon HERBICIDE Pendimethalin HERBICIDE Phosmet ORGANOPHOSPHATE Pyriproxyfen INSECTICIDE Siduron HERBICIDE Simazine HERBICIDE Spinosad INSECTICIDE Thiacloprid NEONIC PESTICIDE Thiamethoxam NEONIC PESTICIDE Thiophanate-methyl FUNGICIDE Trifloxystrobin FUNGICIDE 2. Pathogen screening - We detected a diverse assemblage of Ascosophaera species in Osmia corninfrons. Some species have been reported in closely related Osmia in North America. However one species, Ascosphaera naganensis, is originally from Japan and has most-likely been introduced into North America with movement of Osmia species from Japan to the US in the early 1970s. The existence of this pathogen in North American Osmia populations raises the intriguing possibility that these pathogens are responsible for recent a precipitous declines in Osmia lignaria (the blue orchard mason bee) in the eastern US. We can follow-up on this with future pathogen surveys of O. cornifrons. 3. Bee databasing - Using museum data we have documented the abundance of O. lignaria over the past 140 years in North America and the abundance of O. cornifrons over the past 30 years (since its introduction into the US). Our data reveal that the range expansion of O. cornifrons was delayed relative to its arrival in the US. Most of the range expansion occurred well after they arrived in the 1990s. Furthermore, our historical data suggests that O. lignaria has not shown a significant decline over time. There is no evidence in our historical data that the arrival of O. cornifrons impacted the abundance of O. lignaria. These results provide the first clear test of whether O. lignaria is in decline in North America.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: Hedtke S.M., E.J. Blitzer, G.A. Montgomery, B.N. Danforth (2015). Introduction of non-native pollinators can lead to trans-continental movement of bee-associated fungi. PLoS ONE 10(6): e0130560 [published online 23 June 2015, doi:10.1371/journal.pone.0130560]
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Kleijn, D., R. Winfree, I. Bartomeus, L. Cavalheiro, et al. (2015). Managing for pollinators or pollination: conflicts between biodiversity conservation and ecosystem service delivery. Nature Communications 6:7414 [published online 16 June, 2015, DOI: 10.1038/ncomms8414]
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Park, M.G., E.J. Blitzer, J. Gibbs, J.E. Losey, B.N. Danforth (2015). Combined effect of pesticides and landscape simplification compromises wild pollinators. Proc. Royal Soc. Lond. (B) 282: 20150299 [published online 3 June 2015, DOI: 10.1098/rspb.2015.0299]

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Local Farmers (especially apple farmers) NY State residents The scientific community Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Post-doctoral, Graduate and undergraduate training: Our project involved significant post-doctoral and student training. Mary Centrella, a graduate student in the department of Entomology, took a lead role in the field trap-nesting studies and in the analysis of the historical (museum) data. Mary worked closely with a temporary technician (Cecily Kowitz) to conduct the field experiments. Postdocs Laura Russo, Shannon Hedtke, and Achik Dorchin contributed to the project during the field season. Undergraduate students (including Julia Brokaw, Nolan Amon, and Graham Montgomery) helped with both field and laboratory studies. These students gained considerable expertise in bee biology, taxonomy, computational biology, and pollination biology. How have the results been disseminated to communities of interest? Extension: We interacted significantly with growers over the course of the last year. Extension talks included: Fruit EXPO, Syracuse, NY, Jan. 22, 2014, "Honeybees, CCD, and the importance of wild pollinators for orchard pollination" NY State IPM advisory council meeting, Syracuse, NY, Feb. 25, 2014, "Honeybees, CCD, and the importance of wild pollinators for orchard pollination" Honeybees, CCD, and the importance of wild bees for orchard pollination. Outreach talk at the Ecovillage at Ithaca (February 2014) 2013 - "Distributions of Osmia cornifrons and Osmia lignaria", 2014 Orchard Bee Association Conference, Kayesville, UT (Sept): 45 minute oral presentation 2013 - "Mason Bees as Ideal Pollinators", 2014 Orchard Bee Association Public Exposition, Kayesville, UT (Sept): 15 minute oral presentation What do you plan to do during the next reporting period to accomplish the goals? 1. replicate our Osmia trap nesting experiments across 20 orchards 2. analyze grower spray records in order to identify which of the pesticides detected in pollen provision masses are actually being sprayed in the orchards 3. analyze historical data from museum collections across the US to investigate changes in the relative abundance of O. cornifrons and O. lignaria 4. write up research reports and extension publications

Impacts
What was accomplished under these goals? a) Major activities completed: 1. Pesticide detection - We placed mason bee "trap nests" in 12 apple orchards in Spring 2014. Mason bee populations were seeded with overwintering bees from populations in Ithaca, NY in late April. Mason bees were allowed to establish nests and initiate foraging. Recently completed nests were collected, brought back to the lab, and the pollen/nectar provision masses were removed and analyzed for pesticides. We detected a total of 24 agricultural pesticides, including insecticides, fungicides, herbicides, antimicrobial compounds, organophosphates, and neonicotinoid insecticides. We combined our data on pesticide levels with toxicity data from honey bees to calculate the "hazard quotient" (HQ), a measure of overall toxicity of each pesticide to bees. Some pesticides were detected at very high levels relative to the LD50 for honey bees, including Clothianidin Phosmet, Imidacloprid, Indoxacarb, and Spinosad. 2. Pathogen screening - We screened overwintering adult Osmia cornifrons for pathogens, including viruses, bacteria, and fungi that have been reported previously in honey bees. We used PCR to amplify pathogens from bees and Sanger sequencing to identify the species of pathogens detected. Sequences were compared to existing databases to determine whether the infecting strain shared identity with known honey bee strains or is novel to mason bees. Ascosphaera spp., a fungal pathogen found in social and solitary bees and the causative agent of chalkbrood, was detected in nearly 40% of the bees we screened. Likewise, fungi in the genus Aspergillus (21%), the causative agent of stonebrood in honeybees, and bacteria in the genus Paenibacillus (7.6%) were also relatively common across sites. Based on phylogenetic analysis of sequenced pathogens, we determined that O. cornifrons are infected with a diverse assemblage of Ascosphaera species, one of which appears to have been introduced from Japan through transcontinental movement of bees for agricultural pollination. 3. Bee databasing - There are two species of Osmia that are most significantly utilized in agricultural settings in the US: O. lignaria, an endemic species, and O. cornifrons, intentionally introduced in 1969. Because these species nest in similar structures and have similar foraging ranges, we are interested in whether the introduced species has displaced the native species at a landscape scale. We have been working on mapping Osmia distributions for the past year for both Osmia cornifrons and Osmia lignaria. We have analyzed data from 3243 specimens of bees gathered from 19 insect collections spanning a timeframe from 1850 to 2014. We have graphed abundance trends and mapped distributions for both species. We plan to add at least 9 more collections to this dataset and will analyze data by breaking it into grids per decade to quantify both spatial and temporal changes. Once we have this baseline data, we will be able to compare it to the land-use, temperature, moisture, and crop type changes, using similar grids modified from GIS layer data. To account for sampling error inherent in museum data, we will: a) assess the relative abundance of each species by comparing the two species, with the null hypothesis being that they will have equal spatial and temporal distributions and b) eliminate biases by removing either collectors and/or collections from the data set to see if the results are altered. b) Significant results achieved (major findings, developments, conclusions): 1. Pesticide detection - We detected a surprising diversity of pesticides, many of which are not sprayed on a regular basis on apple orchards. Nearly one half of the pesticides we detected were not sprayed in apple orchards in which we established our nesting sites. These pesticides were colleted by the bees either from neighboring agricultural areas, or they are systemically expressed in plant tissues, such as pollen and nectar. We are following up on this idea and analyzing spray records from our collaborating apple growers to see if the neonicotinoid pesticides, which are known to be expressed systematically and to persist for long periods of time (i.e., years) in the environment. 2. Pathogen screening - We detected a diverse assemblage of Ascosophaera species in Osmia corninfrons. Some species have been reported in closely related Osmia in North America. However one species, Ascosphaera naganensis, is originally from Japan and has most-likely been introduced into North America with movement of Osmia species from Japan to the US in the early 1970s. The existence of this pathogen in North American Osmia populations raises the intriguing possibility that these pathogens are responsible for recent a precipitous declines in Osmia lignaria (the blue orchard mason bee) in the eastern US. We can follow-up on this with future pathogen surveys of O. cornifrons. 3. Bee databasing - Using museum data we have documented the abundance of O. lignaria over the past 140 years in North America and the abundance of O. cornifrons over the past 30 years (since its introduction into the US). Our data reveal that the range expansion of O. cornifrons was delayed relative to its arrival in the US, which most of the range expansion occurring in the 1990s. Furthermore, our historical data suggests that O. lignaria has not shown a significant decline over time. There is no evidence in our historical data that the arrival of O. cornifrons impacted the abundance of O. lignaria. These results provide the first clear test of whether O. lignaria is in decline in North America.

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: Bartomeus, I., M.G. Park, J. Gibbs, B.N. Danforth, A.N. Lakso, & R. Winfree (2013). Biodiversity as insurance against plant-pollinator phenological asynchrony. Ecology Letters 16:1331-1338 [published online 23 August, 2013, doi: 10.1111/ele.12170]
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Kennedy, C.M., E. Lonsdorf, M.C. Neel, et al. (2013). A global quantitative synthesis of local and landscape effects on native bee pollinators in agroecosystems. Ecology Letters 16(5): 584-599.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Bartomeus, I., J.S. Ascher, J. Gibbs, B.N. Danforth, D.L. Wagner, S.M. Hedtke, and R. Winfree (2013). Historical changes in northeastern United States bee pollinators related to shared ecological traits. Proc. Natl. Acad. Sci. (USA) 110(12): 4656-4660.
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Park, M.G., R. Raguso, J.E. Losey, & B.N. Danforth. Effectiveness and importance of wild bees for apple pollination. ESA meeting, Austin, TX (November 10-14, 2013)
• Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Park, M.G., E.J. Blitzer, J. Gibbs, J. Losey, and B.N. Danforth. Natural areas buffer the impact of pesticides on wild pollinators of a perennial crop, International Student Conference on Conservation Science, New York, NY (October 9-11, 2013).
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Park, M.G., R.A. Raguso, E.J. Blitzer, J. Gibbs, J. Losey, & B.N. Danforth (2014). Filling the pollination gap: Assessing the potential for wild bees to maintain adequate apple pollination as honey bee colonies decline. Ecological Society of America meeting, Sacramento CA (Aug. 10-15, 2014)
• Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Russo, L., M.G., Park, B.N. Danforth (2014). Host specialization in a wild bee community: Variation in the composition of pollen collected by apple pollinators. Ecological Society of America meeting, Sacramento CA (Aug. 10-15, 2014)

Progress 10/01/12 to 09/30/13

Outputs
Target Audience: Local Farmers (especially apple farmers) NY State residents The scientific community Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Mia Park a graduate student in the department of Entomology, participated in the study by developing sampling protocols, contacting and communicating with growers, developing grower survey questions, collecting bees, databasing bees, performing bee identifications, and analyzing the relationships between bee species richness/abundance and (1) pesticide use and (2) landscape composition. Post-docs EJ Blitzer and Shannon Hedtke contributed to data collection and analysis. Undergraduate students (including Julia Brokaw and Graham Montgomery) helped with bee survey work, bee databasing, bee identifications, and data analysis. These students gained considerable expertise in bee biology, taxonomy, computational biology, and pollination biology. Four temporary technicians (Edward Hurme, Justin Cappadonna, Sally Hartwick, and Susan Villarreal) were hired to assist with bee surveys and field pollination experiments during the period April-June 2013. How have the results been disseminated to communities of interest? We interacted significantly with growers over the course of the last year. What do you plan to do during the next reporting period to accomplish the goals? We plan to: 1. replicate our Osmia trap nesting experiments across 20 orchards 2. analyze grower spray records in order to identify which of the pesticides detected in pollen provision masses are actually being sprayed in the orchards 3. analyze historical data from museum collections across the US to investigate changes in the relative abundance of O. cornifrons and O. lignaria 4. write up research reports and extension publications

Impacts
What was accomplished under these goals? a) Major activities completed: 1. Pesticide detection – We placed mason bee “trap nests” in 12 apple orchards in Spring 2012 and 2013. Mason bee populations were seeded with overwintering bees from populations in Ithaca, NY in late April. Mason bees were allowed to establish nests and initiate foraging. Recently completed nests were collected, brought back to the lab, and the pollen/nectar provision masses were removed and analyzed for pesticides. We detected a total of 24 agricultural pesticides, including insecticides, fungicides, herbicides, antimicrobial compounds, organophosphates, and neonicotinoid insecticides. We combined our data on pesticide levels with toxicity data from honey bees to calculate the “hazard quotient” (HQ), a measure of overall toxicity of each pesticide to bees. Some pesticides were detected at very high levels relative to the LD50 for honey bees, including Clothianidin Phosmet, Imidacloprid, Indoxacarb, and Spinosad. 2. Pathogen screening – We screened overwintering adult Osmia cornifrons for pathogens, including viruses, bacteria, and fungi that have been reported previously in honey bees. We used PCR to amplify pathogens from bees and Sanger sequencing to to identify the species of pathogens detected. Sequences were compared to existing databases to determine whether the infecting strain shared identity with known honey bee strains or is novel to mason bees. Ascosphaera spp., a fungal pathogen found in social and solitary bees and the causative agent of chalkbrood, was detected in nearly 40% of the bees we screened. Likewise, fungi in the genus Aspergillus (21%), the causative agent of stonebrood in honeybees, and bacteria in the genus Paenibacillus (7.6%) were also relatively common across sites. Based on phylogenetic analysis of sequenced pathogens, we determined that O. cornifrons are infected with a diverse assemblage of Ascosphaera species, one of which appears to have been introduced from Japan through transcontinental movement of bees for agricultural pollination. b) Significant results achieved (major findings, developments, conclusions): 1. Pesticide detection – We detected a surprising diversity of pesticides, many of which are not sprayed on a regular basis on apple orchards. Nearly one half of the pesticides we detected were not sprayed in apple orchards in which we established our nesting sites. These pesticides were collected by the bees either from neighboring agricultural areas, or they are systemically expressed in plant tissues, such as pollen and nectar. We are following up on this idea and analyzing spray records from our collaborating apple growers to see if the neonicotinoid pesticides, which are known to be expressed systematically and to persist for long periods of time (i.e., years) in the environment. 2. Pathogen screening – We detected a diverse assemblage of Ascosophaera species in Osmia corninfrons. Some species have been reported in closely related Osmia in North America. However one species, Ascosphaera naganensis, is originally from Japan and has most-likely been introduced into North America with movement of Osmia species from Japan to the US in the early 1970s. The existence of this pathogen in North American Osmia populations raises the intriguing possibility that these pathogens are responsible for recent a precipitous declines in Osmia lignaria (the blue orchard mason bee) in the eastern US. We can follow-up on this with future pathogen surveys of O. cornifrons.

Publications