Wild Bumblebee (Bombus) Diversity and Nosema (Microsporidia: Nosematidae) Infection Levels Associated with Lowbush Blueberry (Vaccinium angustifolium) Production and Commercial Bumblebee Pollinators

The primary objective was to determine if the prevalence of Nosema bombi infection is higher for wild bumblebees (Bombus spp.) caught in lowbush blueberry growing areas with a history of commercial bumblebee use than for bumblebees caught in areas without a history of commercial bumblebee use. Additionally, we wished to determine relative Bombus species abundances and diversity in blueberry growing regions. Over two years we caught, identified to species, and dissected 767 bumblebees. Light microscopy revealed overall infection levels of 5.48%. The history of commercial bumblebee use had no relation to infection levels. Bumblebee species diversity and field location had significant relationships to infection (r 2 adjusted = 0.265; species diversity F (1,22) = 6.848, P = 0.016; field region F (1,22) = 5.245, P = 0.032). The absence or presence of one species, Bombus terricola, appears to determine the relationship between species diversity and infection. The data show B. terricola decline in sampled regions and almost half of the collected B. terricola were infected with Nosema. The commercial species, B. impatiens, shows an increase in abundance, but with a 6.9% proportion infection. Molecular confirmation of the infecting species was ambiguous, suggesting a need for future clarification of the infecting species

2011 Wild Blueberry Project Reports

The 2011 edition of the Wild Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1. Mechanisms through which wild blueberries affect functional characteristics of the arterial wall related to endothelial dysfunction in Spontaneously Hypertensive Rats 2. Do wild blueberries affect high blood lipids, high blood glucose and obesity as related to the Metabolic Syndrome? 3. Control tactics for blueberry pest insects, 2011 4. IPM strategies, 2011 5. Biology and ecology of pest insects, 2011 6. Biology and ecology of beneficial insects, 2011 7. Pesticide residues on lowbush blueberry, 2011 8. Maine wild blueberry –mummy berry research and extension 9. Valdensinia leaf spot – Education, control and research – 2011 10. Effect of soil pH on nutrient uptake 11. Evaluation of several growth regulators for stimulating lowbush blueberry rhizome production 12. Evaluation of the effects of Gypsum (CaSO4) on wild blueberry fruit Ca concentration 13. Fall application of tribenuron methyl for bunchberry control in wild blueberries, 2009-2011 – effects of fall versus spring pruning on cover and yield in the crop year (final report) 14. Wild Blueberry Extension Education Program in 2011 INPUT SYSTEMS STUDY: 15. Systems approach to improving the sustainability of wild blueberry production, Year 2 of a four-year study – experimental design 16. The effects of different agronomic practices on the composition and quality of wild blueberries 17. Systems approach to improving the sustainability of wild blueberry production, Year 2 of a four-year study, blueberry quality from the first harvest year 18. Food safety- Prevalence study of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. on lowbush blueberries (Vaccinium angustifolium) 19. Abundance of insect pest species and natural enemies in lowbush blueberry fields maintained under different management practices 20. Systems approach to improving the sustainability of wild blueberry production, Year 2 of a four-year study, disease management results 21. Systems approach to improving the sustainability of wild blueberry production, Year 2 of a four-year study, weed management results 22. Systems approach to improving sustainability of wild blueberry production, Year 1 of a four-year study, preliminary soil health and chemistry results 23. Management effects on the phosphorus chemistry of wild blueberry barrens soil 24. Systems approach to improving the sustainability of wild blueberry production, preliminary economic comparison 2010-2011 25. Transition to organic production Year 2: Evaluation of gypsum and bone char 26. The effect of field management, forest edge composition, and field location on insect-mediated ecosystem services (scavenging/predation) (ancillary study) 27. Pre-emergent combinations of herbicides for weed control in wild blueberry fields (ancillary study) 28. Systems approach to improving the sustainability of wild blueberry production – Ancillary land-leveling study, year 1 (ancillary study) 29. Effects of compost and mulch on soil health and soil nutrient dynamics in wild blueberry (ancillary study

2012 Wild Blueberry Project Reports

The 2012 edition of the Wild Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1. Do wild blueberries alleviate risk factors related to the Metabolic Syndrome? 2. Development of effective intervention measures to maintain and improve food safety for wild blueberries 3. Control tactics for blueberry pest insects, 2012 4. Development and implementation of a wild blueberry thrips IPM program, 2012 5. IPM 6. Biology of blueberry and pest insects, 2012 7. Biology of beneficial insects and blueberry pollination, 2012 8. Pesticide residues on lowbush blueberry, 2012 9. Maine wild blueberry –mummy berry research and extension 10. Efficacy of Apogee growth regulator for stimulating rhizome growth into bare spots in wild blueberry fields 11. Velpar by Matrix pre and post-emergence applications - demonstration plots 12. Wild blueberry Extension Education Program in 2012 INPUT SYSTEMS STUDY: 13. Systems approach to improving the sustainability of wild blueberry production, Year Three of a four-year study – experimental design 14. Food safety- Prevalence study of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. on lowbush blueberries (Vaccinium angustifolium) 15. Abundance of insect pest species and natural enemies in lowbush blueberry fields maintained under different management practices 16. Input Systems Study: Systems approach to improving the sustainability of wild blueberry production, Year 3 of a four-year study, disease management results 17. Plant productivity, Year Three of a four-year study 18. Systems approach to improving the sustainability of wild blueberry production, Year Three of a four-year study, weed management results 19. Effects of organic and conventional management systems on the phosphorus solubility of lowbush blueberry barren soils 20. Systems approach to improving sustainability of wild blueberry production – soil health and chemistry measures 21. Evaluation of fungicides for control of mummy berry disease (ancillary study) 22. Systems approach to improving the sustainability of wild blueberry production – Ancillary land-leveling study, Year Two of a four-year study (ancillary study) 23. Pre-emergent combinations of herbicides for weed control in wild blueberry fields – 2012 results from the 2011 trial (ancillary study) 24. Pre-emergent combinations of herbicides for weed control in wild blueberry fields – 2012 trial (ancillary study) 25. Evaluation of herbicides for control of fineleaf sheep fescue for grass control in wild blueberries (ancillary study) 26. Pre-emergence application timing and rate of Alion and Sandea in combination with Velpar or Sinbar on weed control and injury to wild blueberry (ancillary study) 27. Compost and mulch effects on soil health and nutrient dynamics in wild blueberry (ancillary study

2013 Wild Blueberry Project Reports

The 2013 edition of the Wild Blueberry Project Reports was prepared for the Wild Blueberry Commission of Maine and the Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1. Development of effective intervention measures to maintain and improve food safety for wild blueberries 2. Do wild blueberries alleviate risk factors related to the Metabolic Syndrome? 3. Wild Blueberry consumption and exercise-induced Oxidative Stress: Inflammatory Response and DNA damage 4. Control tactics for blueberry pest insects, 2013 5. Pesticide residues on wild blueberry, 2013 6. Biology of pest insects and IPM, 2013 7. Biology of blueberry, beneficial insects, and blueberry pollination 8. Biology of spotted wing drosophila, 2013 9. Maine wild blueberry –mummy berry research and extension 10. Evaluation of fungicides for control of mummy berry on lowbush blueberry (2013) 11. Wild blueberry Extension Education Program in 2013 INPUT SYSTEMS STUDY: 12. Systems approach to improving the sustainability of wild blueberry production, Year Four of a four-year study – experimental design 13. Food safety- Prevalence study of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella spp. on lowbush blueberries (Vaccinium angustifolium) 14. Agronomic input effects on sensory quality and chemical composition of wild Maine blueberries 15. Systems approach to improving the sustainability of wild blueberry production, Year four of a four-year study – reports from Frank Drummond 16. Systems approach to improving the sustainability of wild blueberry production, Year 4 of a four-year study, disease management results 17. Systems approach to improving the sustainability of wild blueberry production, Year Four of a four-year study, weed management results 18. Phosphorus and organic matter interactions on short-range ordered minerals in acidic barren soils 19. Systems approach to improving the sustainability of wild blueberry production, preliminary economic comparison for 2012-13 20. Ancillary projects in disease research (ancillary study) 21. Systems approach to improving the sustainability of wild blueberry production – Ancillary land-leveling study, Year Three of a four-year study (ancillary study) 22. Pre-emergent combinations of herbicides for weed control in wild blueberry fields – 2013 results from the 2012 trial (ancillary study) 23. Evaluation of herbicides for 2012 prune year control of fineleaf sheep fescue in wild blueberries – 2013 crop year results (ancillary study) 24. 2012 pre-emergence application timing and rate of Alion and Sandea in combination with Velpar or Sinbar – 2013 yields (ancillary study) 25. Pre-emergence Sinbar combinations for weed control in a non-crop wild blueberry field – 2012-2014 (ancillary study) 26. Evaluation of three pre-emergence herbicides alone and in combination with Velpar or Sinbar for effects on wild blueberry productivity and weed control (ancillary study) 27. Post-harvest control of red sorrel in a non-crop blueberry field, 2012-2014 (ancillary study) 28. Compost and mulch effects on soil health and nutrient dynamics in wild blueberry (ancillary study) 29. Evaluation of conventional and organic fertilizers on blueberry growth and yield (ancillary study

Wild Bee (Hymenoptera: Apoidea) Communities Associated with the Lowbush Blueberry Agroecosystem of Maine

The lowbush blueberry (Ericaceae: Vaccinium angustifolium) is native to North America. Insect pollination is required for fruit set and bees (Hymenoptera: Apoidea) are the most common and efficient pollinators. Growers rely on combinations of managed honeybees, commercially reared bumblebees and naturally occurring wild bees for pollination services. This study explores three main questions important for understanding wild bee communities associated with lowbush blueberry production. 1. What is the diversity and abundance of wild bees in Downeast Maine blueberry fields and what factors impact the bee communities? 2. Does the use of commercial bumblebees (Bombus impatiens Cresson) impact wild bumblebee communities by contributing to the prevalence of the microsporidian parasite Nosema bombi? 3. What economic contributions do wild bee communities provide to blueberry growers? This study documents 133 wild bee species found in 40 study fields, along with an additional six species from supplemental fields. Twenty-two of these species have not been previously recorded in Maine. Wild bee diversity fluctuates over the three study years with no evidence that farm management practices influence bee community structure. Wild bee abundance is negatively related to the proportion of blueberry cropland within 500 m of the field borders and positively related to the proportion of deciduous forest and cleared forest within 500 m. Based on a sample of 767 bumblebee workers caught over a two-year period, Nosema infection levels of 5.48% were recorded. Infection levels have no relation to the use of commercial Bombus impatiens colonies for pollination, providing no support for a pathogen spillover hypothesis. Populations of B. terricola (Kirby) show evidence of decline with a Nosema infection prevalence of 46.2%, a local trend which reflects nationwide patterns. Three fruit set measures, yield (kg/ha), and value of crop (dollars/ha) were recorded for the study fields. Fruit set, yield, and value of crop were positively related. Fruit set, yield, and value of crop were also positively related to the abundance of all wild bees, bumblebees, and honeybees recorded foraging in the fields. Wild bee and bumblebee activity influenced fruit set and yield measures with 2-8 times the impact of honeybees

Analysis of Pollination Services Provided by Wild and Managed Bees (Apoidea) in Wild Blueberry (Vaccinium angustifolium Aiton) Production in Maine, USA, with a Literature Review

Maine is the largest producer of wild blueberry (Vaccinium angustifolium Aiton) in the United States. Pollination comes from combinations of honey bees (Apis mellifera (L.)), commercial bumble bees (Bombus impatiens Cresson), and wild bees. This study addresses (1) previous research addressing wild-blueberry pollination, (2) effects of wild-bee and honey-bee activity densities on fruit set, yield, and crop value, (3) the economic value of wild-bee communities, and (4) economic consequences of pollinator loss. Bee communities were sampled in 40 fields over three years (2010–2012) and bee activity densities were estimated for bumble bees, honey bees, and other wild bees. These data were applied to an economic model to estimate the value of bee taxa. Bumble bees and honey bees predicted fruit set and reduced its spatial heterogeneity. Other wild bees were not significant predictors of fruit set. Yield was predicted by fruit set and field size, but not pest management tactics. Our analysis showed that disruption in supply of honey bees would result in nearly a 30% decrease in crop yield, buffered in part by wild bees that provide “background” levels of pollination. Honey-bee stocking density and, thus, the activity density of honey bees was greater in larger fields, but not for wild bees. Therefore, a decrease in crop yield would be greater than 30% for large fields due to the proportionally greater investment in honey bees in large fields and a relatively lower contribution by wild bees

Call to restrict neonicotinoids

On 28 April 2018 the European Parliament voted for a complete and permanent ban on all outdoor uses of the three most commonly used neonicotinoid pesticides. With the partial exception of the state of Ontario, Canada, governments elsewhere have failed to take action. Below is a letter, signed by 232 scientists from around the world, urgently calling for global action by policy makers to address this issue