Insect Pollinated Crops, Insect Pollinators and US Agriculture: Trend Analysis of Aggregate Data for the Period 1992–2009

264

236

As a managed pollinator, the honey bee Apis mellifera is critical to the American agricultural enterprise. Recent colony losses have thus raised concerns; possible explanations for bee decline include nutritional deficiencies and exposures to pesticides and pathogens. We determined that constituents found in honey, including p- coumaric acid, pinocembrin, and pinobanksin 5-methyl ether, specifically induce detoxification genes. These inducers are primarily found not in nectar but in pollen in the case of p- coumaric acid (a monomer of sporopollenin, the principal constituent of pollen cell walls) and propolis, a resinous material gathered and processed by bees to line wax cells. RNA-seq analysis (massively parallel RNA sequencing) revealed that p- coumaric acid specifically up-regulates all classes of detoxification genes as well as select antimicrobial peptide genes. This up-regulation has functional significance in that that adding p- coumaric acid to a diet of sucrose increases midgut metabolism of coumaphos, a widely used in-hive acaricide, by ∼60%. As a major component of pollen grains, p- coumaric acid is ubiquitous in the natural diet of honey bees and may function as a nutraceutical regulating immune and detoxification processes. The widespread apicultural use of honey substitutes, including high-fructose corn syrup, may thus compromise the ability of honey bees to cope with pesticides and pathogens and contribute to colony losses.

Section: Abaecin | Cytochrome P450mentioning

confidence: 99%

Honey constituents up-regulate detoxification and immunity genes in the western honey bee Apis mellifera

Mao¹,

Schuler

Berenbaum³

2013

264

236

“…1D, and adds others. In these counties, regardless of whether demand for pollination services has already overtaken the ability of wild bees to supply them, recent trends indicate that the risk is growing over time (6). Growers of crops dependent on bees for pollination will need to depend more heavily on managed honey bees to supply pollination in the absence of abundant wild bee populations.…”

Section: Discussionmentioning

confidence: 99%

Modeling the status, trends, and impacts of wild bee abundance in the United States

Koh

Lonsdorf

Williams

et al. 2015

404

315

Wild bees are highly valuable pollinators. Along with managed honey bees, they provide a critical ecosystem service by ensuring stable pollination to agriculture and wild plant communities. Increasing concern about the welfare of both wild and managed pollinators, however, has prompted recent calls for national evaluation and action. Here, for the first time to our knowledge, we assess the status and trends of wild bees and their potential impacts on pollination services across the coterminous United States. We use a spatial habitat model, national land-cover data, and carefully quantified expert knowledge to estimate wild bee abundance and associated uncertainty. Between 2008 and 2013, modeled bee abundance declined across 23% of US land area. This decline was generally associated with conversion of natural habitats to row crops. We identify 139 counties where low bee abundances correspond to large areas of pollinator-dependent crops. These areas of mismatch between supply (wild bee abundance) and demand (cultivated area) for pollination comprise 39% of the pollinator-dependent crop area in the United States. Further, we find that the crops most highly dependent on pollinators tend to experience more severe mismatches between declining supply and increasing demand. These trends, should they continue, may increase costs for US farmers and may even destabilize crop production over time. National assessments such as this can help focus both scientific and political efforts to understand and sustain wild bees. As new information becomes available, repeated assessments can update findings, revise priorities, and track progress toward sustainable management of our nation's pollinators.crop pollination | ecosystem services | habitat suitability | land-use change | uncertainty B ees and other flower-visiting animals provide essential pollination services to many US crops (1) and to wild plant species (2). Bees contributed an estimated 11% of the nation's agricultural gross domestic product in 2009 (3), equal to $14.6 billion per year (4). Of this, at least 20% ($3.07 billion) is provided by wild pollinators that depend on suitable land for nesting and foraging (5). As the consumption of specialty fruit and vegetable crops has grown (6), the demand for pollination services has increased. However, the supply of managed honey bees (Apis mellifera L.) has not kept pace (7), due to management challenges and colony losses over the last decade (8). There is growing evidence that wild, unmanaged bees can provide effective pollination services where sufficient habitat exists to support their populations (9, 10). They can also contribute to the long-term stability of crop pollination, thereby reducing the risk of pollination deficits from variable supply or activity of honey bees (11, 12). As a result, wild pollinators should be integrated into crop pollination management plans as a supplement or alternative to managed bees (13).Despite the agricultural importance of wild bees, there is increasing evidence that multiple species ...

“…apiary selection models | Apis mellifera | land use | land-cover trends | pollinators A nimal pollination service is critical for sustaining ecosystem health and human well-being (1,2). In many terrestrial systems, plant-pollinator interactions provide the basic framework for all other trophic interactions.…”

mentioning

confidence: 99%

“…Globally, about one-third of crop production depends on animal pollination (3). US agricultural production relies heavily on managed and native insects for pollination services, with an estimated economic value of $15 billion annually (2). Reliance on insects for pollination services is growing even as populations of native and managed pollinators exhibit concurrent declines (4,5).…”

mentioning

confidence: 99%

Land-use change reduces habitat suitability for supporting managed honey bee colonies in the Northern Great Plains

Otto

Roth

Carlson

et al. 2016

165

138

Human reliance on insect pollination services continues to increase even as pollinator populations exhibit global declines. Increased commodity crop prices and federal subsidies for biofuel crops, such as corn and soybeans, have contributed to rapid land-use change in the US Northern Great Plains (NGP), changes that may jeopardize habitat for honey bees in a part of the country that supports >40% of the US colony stock. We investigated changes in biofuel crop production and grassland land covers surrounding ∼18,000 registered commercial apiaries in North and South Dakota from 2006 to 2014. We then developed habitat selection models to identify remotely sensed land-cover and land-use features that influence apiary site selection by Dakota beekeepers. Our study demonstrates a continual increase in biofuel crops, totaling 1.2 Mha, around registered apiary locations in North and South Dakota. Such crops were avoided by commercial beekeepers when selecting apiary sites in this region. Furthermore, our analysis reveals how grasslands that beekeepers target when selecting commercial apiary locations are becoming less common in eastern North and South Dakota, changes that may have lasting impact on pollinator conservation efforts. Our study highlights how land-use change in the NGP is altering the landscape in ways that are seemingly less conducive to beekeeping. Our models can be used to guide future conservation efforts highlighted in the US national pollinator health strategy by identifying areas that support high densities of commercial apiaries and that have exhibited significant land-use changes.apiary selection models | Apis mellifera | land use | land-cover trends | pollinators A nimal pollination service is critical for sustaining ecosystem health and human well-being (1, 2). In many terrestrial systems, plant-pollinator interactions provide the basic framework for all other trophic interactions. Globally, about one-third of crop production depends on animal pollination (3). US agricultural production relies heavily on managed and native insects for pollination services, with an estimated economic value of $15 billion annually (2). Reliance on insects for pollination services is growing even as populations of native and managed pollinators exhibit concurrent declines (4, 5). For example, in 2013−2014, total US honey bee colony losses were 34%, but beekeepers on average lost 51% of their colonies (6). Declines in managed honey bees and native bees put significant pressure on global food supplies, plant-pollinator networks, agricultural producers, and ecosystem function (7,8).Proposed reasons for the declines include parasites, diseases, agro-chemical use, forage availability, and land-use change (9, 10). Much of the research investigating anthropogenic disturbance effects on managed and native pollinators focuses on pesticides and less so on habitat fragmentation, land-use, and loss of forage. Although a paucity of data exists for most parts of the world, recent research indicates that land use influences honey ...