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

Recent developments of new families of pesticides and growing awareness of the importance of wild pollinators for crop pollination have stimulated interest in potential effects of novel pesticides on wild bees. Yet pesticide toxicity studies on wild bees remain rare, and few studies have included long-term monitoring of bumble bee colonies or testing of foraging ability after pesticide exposure. Larval bees feeding on exogenous pollen and exposed to pesticides during development may result in lethal or sub-lethal effects during the adult stage. We tested the effects of a naturally derived biopesticide, spinosad, on bumble bee (Bombus impatiens Cresson) colony health, including adult mortality, brood development, weights of emerging bees and foraging efficiency of adults that underwent larval development during exposure to spinosad. We monitored colonies from an early stage, over a 10-week period, and fed spinosad to colonies in pollen at four levels: control, 0.2, 0.8 and 8.0 mg kg(-1), during weeks 2 through 5 of the experiment. At concentrations that bees would likely encounter in pollen in the wild (0.2-0.8 mg kg(-1)) we detected minimal negative effects to bumble bee colonies. Brood and adult mortality was high at 8.0 mg kg(-1) spinosad, about twice the level that bees would be exposed to in a 'worst case' field scenario, resulting in colony death two to four weeks after initial pesticide exposure. At more realistic concentrations there were potentially important sub-lethal effects. Adult worker bees exposed to spinosad during larval development at 0.8 mg kg(-1) were slower foragers on artificial complex flower arrays than bees from low or no spinosad treated colonies. Inclusion of similar sub-lethal assays to detect effects of pesticides on pollinators would aid in development of environmentally responsible pest management strategies.

https://training.fws.gov/resources/course-resources/pesticides/Terrestrial%20Effects/Effect%20of%20spinosad%20on%20bumblebees.pdf

Lethal and sub-lethal effects of spinosad on bumble bees (Bombus impatiens Cresson).

Reproductive fitness of a plant is ultimately determined by both number and quality of seed offspring. This is determined by sexual selection of pollen microspores and ovules during pollination and fertilization. These processes may include pollen competition and seed abortion, which reduce the number of microspores and ovules available for final seed production. Thus, even an excess of pollen microspores to ovules does not result in fertile seeds equal to ovule number. We investigated pollen requirements of highbush blueberry (Vaccinium corymbosum cultivar 'Bluecrop') for maximal seed production and how fertile seed number translates into fruit quality, since fruit quality would ultimately determine the dispersal of its offspring. We demonstrate that individual blueberry flowers with a mean of 106 ovules reach their maximum fruit set and mass and minimum time to ripen when 125 outcross pollen tetrads pollinate a flower, compared to 10 or 25. Three hundred tetrads resulted in the increase of fertile seeds, but did not result in a further increase of fruit mass or fruit set, or decrease in time to ripen. We also examined the effect of pure and mixed loads of self and outcross pollen (25 and 125 tetrads), and found no differences in fertile seed number, fruit mass, or percentage fruit set when pollen loads were either 25 self or outcross pollen tetrads, although number of days to ripen was significantly shorter by 8 d with 25 outcross tetrads. When the pollen load of 125 tetrads consisted of self or a 50:50 mixture of self and outcross pollen, fruit mass, days to ripen, and percentage fruit set were not different from loads of 125 outcross pollen. In addition, a pollen load of 25 outcross tetrads resulted in fertile seed number and fruit quality in between that of 25 self, and 125 self, 125 mixed, or 125 outcross tetrads. Large, small, and flat seed types were identified, and only large seeds (length = 1.7 mm) were fertile. These results improve our understanding of pollen load size and source requirements of a crop plant and the limits to pollen transfer when translated to fruit growth.

https://bsapubs.onlinelibrary.wiley.com/doi/pdf/10.2307/2656734

Effect of pollen load size and source (self, outcross) on seed and fruit production in highbush blueberry cv. ‘Bluecrop’ (VACCINIUM CORYMBOSUM; Ericaceae)

This article outlines the rationale for a molecular genetic study of social behavior, and explains why social insects are good models. Summaries of research on brain and behavior in two species, honey bees and fire ants, are presented to illustrate the richness of the behavioral phenomena that can be addressed with social insects and to show how they are beginning to be used to study genes that influence social behavior. We conclude by considering the problems and potential of this emerging field.

Insect societies and the molecular biology of social behavior

Foraging differences between cross-fostered honeybee workers of European and Africanized races in South America are described. Africanized workers began foraging at earlier ages than European workers in colonies of their own races, but cross-fostered workers began foraging at the same age as workers in the colonies in which they were placed. Some differences in the mean time spent foraging per hour and the mean number of flights per hour were also found. The results suggest two major factors determining differences in division of labor between Africanized and European bees: 1) the colony characteristics by which foraging age is determined, and 2) the responses of individual workers to hive environment. A hypothesis to explain these results is presented based on higher levels of foraging stimuli in Africanized colonies as well as a higher stimulus threshold for Africanized workers.

Foraging differences between cross-fostered honeybee workers (Apis mellifera) of European and Africanized races

J:S:TROD UCTIO:S: :\\LH ERI:\\LS ;\\{ETHODS CONTENTS TRA:S:SP ORT OF NEsTI'.\\'. G .\\IATERI :\\LS MA,IPCLATIO:'\\ OF ScE:'\\Ts B Y :\\hLE Ec GLoss1,1 APID PoLLE'.\\'. J-. L,sIPULATIO'.\\'. .............. . The Forelegs ---·----·--·-· ............. . . Pollen Packing ····---·--------·• •· Typ e I Pollen Packing --·-----·········· . ·····-·•·-----·--· Typ e II Poll en Packing ·-··---------········-··············•-·· Ip ~ilateral Type II Poll en Packin g ......... ·········-· Contralateral Pollen Packing in A pis and Bom b11s --··----···· Contralateral Pollen Packing in l\\leliponinae ········-·······-····· The Corbicular Pollen Loa<l in :\\Ieliponinae ---· Specializatio ns of Meliponine Pollen Collecting ......... ····-··· The Euglo ssini -···-·-----------·····················--··-·-·-···-··· E, ·0LuT10-.:ARY Co:-.srnERATIO-.:s ---··· ·········-·-·-·-----··· Ernlution of Poll en Collecting and Tr ansport . ·····---------·-·· Ernlution of Corbiculae and their Filling :\\!echani sms -·· ........................ ----.. Poll en-Packing in the Api<lae .......... ······-·--·· DeriYati on of Pollen Manipulati on from Self-Grooming J-.l on:mcnt~ AcK:'\\OWLEDGE:\\IE'.\\'.TS ------·· ................ ----···LITERATCRE CITED ---------·······----------·-· ABSTRACT 575 576 577 57S 579 5~0 Sb! Sb! 5il2 5S2 583 5113 587 58S 590 590 593 59--l 59--l 595 597 59S 600 600575 576 577 57S 579 5~0 Sb! Sb! 5il2 5S2 583 5113 587 58S 590 590 593 59--l 59--l 595 597 59S 600 600 Poll en m anipul ation is descri bed for all major groups of Api<lae, and for comparati\\'e purpose s, oth er hees are also considered. In prototypic pollen collecting, pollen is remo\\' ed from th e fro nt leg s and head, and carried in the crop. In euty pie pollen collecting, it is re m o\\'ed from th e fr ont and mid legs as well as surfaces of th e head and thorax and trans ferr ed by th e m id dle legs to the scopa on th e hind legs . Diff eren t derived or metat ypic types of pollen m ani pu lation su pp lement the eutypic beha\\'ior and provide for transfer of pollen to th e abd om in al scopa in the ~1egachilidae and from th e abdomen to the hind tibiae in the A p idae. In Ap idae th e bru shy scopa of many other bees is modifie<l into a corbicular scopa, which with th e hin d tibia l sur face fo rms the corbicula. Corbicular filling ( = pollen packing) can be 2 Department of Entomo logy, 3 Department of Systematics an<l Ecology, an<l 4 Snow Entomolo gica l Museum, University of Kansa s, Lawrence, Kansas 660--15, U.S.A . 1 Contribution number I 659 from the Department of Entomology, UniYer~ity of Kansas, Lawrence, Kansas 660--15, U.S.A. 576 T11E UNIVERSITY OF KAN S,\\S SCIENCE BPLLETIN achieYecl with little or no moclification of cutypical behaYior; for Apiclae this is called Type I pollen packing, in whic h pollen is put directly into the corbiculae hy the midclle legs. Nesting materials arc packed and tran sportecl in the same way. On the other hand, the corbicula is usually loaded with pollen from its distal end. This is Type II pollen packing. It may be either (a) ipsilateral, a modified eutypic pattern in which pollen is placed on the outside of the tihiotarsal joint by the middle leg of the same sicle, and thenc e pushed basad into the corbicula, or (b) contra lat eral, a deriYed pattern in which pollen transf erred hy the middle legs to th e inner surfaces of the hind basitarsi or swept from the ab<lomen by those basitarsi, is transferred to th e corbicula of the opposite tibia. In pollen-manipulating mo\\'ements and structures, certain ~Ieliponinae appear to be the most primiti\\'e apids, apparently lacking Type II pollen-packing behavior as well as structures necessary for it. For other l\\Ieliponinae, ipsilateral Type II pollen packing is most important, although some have contralateral Type II behavior as part of their repertoire. The small hind hasitarsus without an auricle suggests that contralateral Type II packing is of little importance in most Meliponinae, altho ugh an auricular area can function like the auricle to push pollen basad into the corbicula. Euglossini are inadequately studied, but probably exhibit ipsilateral Type II behaYior. Bombini ancl Apinae are similar to one another in pollenhandling structure and behavior and for both, contralateral Type II pollen packing is a principal method. ?v!odifications of usual pollen-manipulating moYements are seen in scent manipulation by male euglossine bees and in pollen-gleaning actiYity by certain Meliponinae ( Scaura ). Most of th e pollen-manipulation mo\\'ements are either the same as self-grooming movements or are opposites of them so that, for example, a structure that is stroked distally for cleaning may be stroked basally to load it with pollen, the cleaning moYement proper serving later for unloading. Presumably such loading movements are deriYed from similar cleaning movements. Only the hind basitarsal moYements that push pollen basad into the corbicula lack counterparts in cleaning or other known behavior.

/pdf/pollen-manipulation-and-related-activities-and-structures-in-4hdy2z9exd.pdf

Mark L. Winston

Papers

Lethal and sub-lethal effects of spinosad on bumble bees (Bombus impatiens Cresson).

Effect of pollen load size and source (self, outcross) on seed and fruit production in highbush blueberry cv. ‘Bluecrop’ (VACCINIUM CORYMBOSUM; Ericaceae)

Insect societies and the molecular biology of social behavior

Foraging differences between cross-fostered honeybee workers (Apis mellifera) of European and Africanized races

Pollen manipulation and related activities and structures in bees of the family Apidae