The extent of our reliance on animal pollination for world crop production for human food has not previously been evaluated and the previous estimates for countries or continents have seldom used primary data. In this review, we expand the previous estimates using novel primary data from 200 countries and found that fruit, vegetable or seed production from 87 of the leading global food crops is dependent upon animal pollination, while 28 crops do not rely upon animal pollination. However, global production volumes give a contrasting perspective, since 60% of global production comes from crops that do not depend on animal pollination, 35% from crops that depend on pollinators, and 5% are unevaluated. Using all crops traded on the world market and setting aside crops that are solely passively self-pollinated, wind-pollinated or parthenocarpic, we then evaluated the level of dependence on animal-mediated pollination for crops that are directly consumed by humans. We found that pollinators are essential for 13 crops, production is highly pollinator dependent for 30, moderately for 27, slightly for 21, unimportant for 7, and is of unknown significance for the remaining 9. We further evaluated whether local and landscape-wide management for natural pollination services could help to sustain crop diversity and production. Case studies for nine crops on four continents revealed that agricultural intensification jeopardizes wild bee communities and their stabilizing effect on pollination services at the landscape scale.

/pdf/importance-of-pollinators-in-changing-landscapes-for-world-2j8o9ygr29.pdf

Importance of pollinators in changing landscapes for world crops

Pollinators are a key component of global biodiversity, providing vital ecosystem services to crops and wild plants. There is clear evidence of recent declines in both wild and domesticated pollinators, and parallel declines in the plants that rely upon them. Here we describe the nature and extent of reported declines, and review the potential drivers of pollinator loss, including habitat loss and fragmentation, agrochemicals, pathogens, alien species, climate change and the interactions between them. Pollinator declines can result in loss of pollination services which have important negative ecological and economic impacts that could significantly affect the maintenance of wild plant diversity, wider ecosystem stability, crop production, food security and human welfare.

/pdf/global-pollinator-declines-trends-impacts-and-drivers-5gfi4zur4k.pdf

Global pollinator declines: trends, impacts and drivers.

Bees are subject to numerous pressures in the modern world. The abundance and diversity of flowers has declined, bees are chronically exposed to cocktails of agrochemicals, and they are simultaneously exposed to novel parasites accidentally spread by humans. Climate change is likely to exacerbate these problems in the future. Stressors do not act in isolation; for example pesticide exposure can impair both detoxification mechanisms and immune responses, rendering bees more susceptible to parasites. It seems certain that chronic exposure to multiple, interacting stressors is driving honey bee colony losses and declines of wild pollinators, but such interactions are not addressed by current regulatory procedures and studying these interactions experimentally poses a major challenge. In the meantime, taking steps to reduce stress on bees would seem prudent; incorporating flower-rich habitat into farmland, reducing pesticide use through adopting more sustainable farming methods, and enforcing effective quarantine measures on bee movements are all practical measures that should be adopted. Effective monitoring of wild pollinator populations is urgently needed to inform management strategies into the future.

https://science.sciencemag.org/content/sci/early/2015/02/25/science.1255957.full.pdf

Bee declines driven by combined stress from parasites, pesticides, and lack of flowers

https://www1.montpellier.inra.fr/lameta/articles/5.4.2_POLLINATION.pdf

Economic valuation of the vulnerability of world agriculture confronted with pollinator decline

Plant essential oils for pest and disease management

1. Introduction 2. The Origins and Evolutionary History of Bees 3. Form and Function: Honey Bee Anatomy 4. Development and Nutrition 5. Nest Architecture 6. The Age-Related Activities of Worker Bees 7. Other Worker Activities 8. The Chemical World of Honey Bees 9. Communication and Orientation 10. The Collection of Food 11. Reproduction: Swarming and Supersedure 12. Drones, Queens, and Mating 13. The Biology of Temperate and Tropical Honey Bees Reference Author Index Subject Index

The Biology of the Honey Bee

Recent studies have demonstrated a remarkable and unexpected complexity in social insect pheromone communication, particularly for honeybees (Apis mellifera L.). The intricate interactions characteristic of social insects demand a complex language, based on specialized chemical signals that provide a syntax that is deeper in complexity and richer in nuance than previously imagined. Here, we discuss this rapidly evolving field for honeybees, the only social insect for which any primer pheromones have been identified. Novel research has demonstrated the importance of complexity, synergy, context, and dose, mediated through spatial and temporal pheromone distribution, and has revealed an unprecedented wealth of identified semiochemicals and functions. These new results demand fresh terminology, and we propose adding "colony pheromone" and "passenger pheromone" to the current terms sociochemical, releaser, and primer pheromone to better encompass our growing understanding of chemical communication in social insects.

Pheromone Communication in the Honeybee ( Apis mellifera L.)

The substance produced by the mandibular gland complex (HQMC) of queen honey bees is considered to be responsible for retinue formation in honey bees, Apis mellifera L.1–3. The retinue response includes the licking and antennating behaviour which signals the presence of a dominant reproductive queen and thereby establishes and stabilizes the social fabric of the colony. Despite 25 years of research, none of the known constituents of HQMC extract4,5 has been effective in eliciting full retinue behaviour. We report that the mandibular-gland-based retinue response is mediated by five semiochemicals. Each component is weakly active alone, but the complete blend imparts activity equivalent to HQMC extract at a level as low as 10–7 of that present in a queen.

Semiochemical basis of the retinue response to queen honey bees

We report results that address a long-standing controversy in honey bee biology, the identity of the queen-produced compounds that inhibit worker honey bee ovary development. As the honey bee is the only organism for which identities have been proposed for any pheromone that regulates reproduction, the resolution of its identity is of broad significance. We examined the effects of synthetic honey bee queen mandibular pheromone (QMP), four newly identified queen retinue pheromone components, and whole-queen extracts on the ovary development of caged worker bees. The newly identified compounds did not inhibit worker ovary development alone, nor did they improve the efficacy of QMP when applied in combination. QMP was as effective as queen extracts at ovary regulation. Caged workers in the QMP and queen extract treatments had better developed ovaries than did workers remaining in queenright colonies. We conclude that QMP is responsible for the ovary-regulating pheromonal capability of queens from European-derived Apis mellifera subspecies.

The effect of queen pheromones on worker honey bee ovary development.

The ecological impacts of agriculture are of concern, especially with genetically modified and other intensive, modern cropping systems, yet little is known about effects on wild bee populations and subsequent implications for pollination. Pollination deficit (the difference between potential and actual pollination) and bee abundance were measured in organic, conventional, and herbicide-resistant, genetically modified (GM) canola fields (Brassica napus and B. rapa) in northern Alberta, Canada, in the summer of 2002. Bee abundance data were collected using pan traps and standardized sweep netting, and pollination deficit was assessed by comparing the number of seeds per fruit from open-pollinated and supplementally pollinated flowers. There was no pollination deficit in organic fields, a moderate pollination deficit in conventional fields, and the greatest pollination deficit in GM fields. Bee abundance was greatest in organic fields, followed by conventional fields, and lowest in GM fields. Overall, there...

Mark L. Winston

Papers

The Biology of the Honey Bee

Pheromone Communication in the Honeybee ( Apis mellifera L.)

Semiochemical basis of the retinue response to queen honey bees

The effect of queen pheromones on worker honey bee ovary development.

Wild bee abundance and seed production in conventional, organic, and genetically modified canola