View source for Pollinator decline

'''Pollinator decline''' is based on observations made at the end of the twentieth century of the reduction in abundance of [[pollinator]]s in many [[ecosystem]]s worldwide.

Pollinators participate in sexual reproduction of many [[plant]]s, by ensuring cross-[[pollination]], essential for some [[species]], or a major factor in ensuring [[genetic diversity]] for others. Since [[plant]]s are the primary [[food]] source for [[animal]]s, the reduction of one of the primary pollination agents, or even their possible disappearance, has raised concern, and the [[Conservation ethic|conservation]] of pollinators has become part of [[biodiversity]] conservation efforts.

==Observation of pollinator decline ==

As [[agriculture|plantings]] have grown larger, the need for concentrated pollinators at [[flower|bloom]] time has grown. At the same time populations of many pollinators has been declining, and this decline has become a major [[List of environmental issues|environmental issue]] today. [[Pollination management]] seeks to protect, enhance, and augment agricultural pollination.

For example, feral [[honey bee]] populations in the US have dropped about 90% in the past 50 years, except for the Southwest where they have been replaced by [[africanized bee]]s. At the same time [[beekeeping|managed honey bee colonies]] have dropped by about two thirds.

[[Monoculture]] needs very high populations at bloom, but can make the area quite barren, or even toxic when the bloom is done.

The study of pollinator decline is also interesting some scientists, as bees have the potential to become a keystone [[indicator species]] of environmental degradation. Any changes in their abundance and diversity will influence the abundance and diversity of the prevailing plant species.  This is a mutual dependency as bees rely on a steady [[nectar source]] and [[pollen source]] throughout the year to build up their hive.

== Consequences ==

The value of bee pollination in human [[nutrition]] and [[food]] for [[wildlife]] is immense and difficult to quantify. 

It is commonly said that about one third of human nutrition is due to bee pollination. This includes the majority of [[fruit]]s, many [[vegetable]]s (or their [[seed crop]]) and secondary effects from [[legume]]s such as [[alfalfa]] and [[clover]] fed to livestock. 

In 2000 Drs. [[Roger Morse]] and Nicholas Calderone of [[Cornell University]], attempted to quantify the effects of just one pollinator, the [[honeybee]], on only [[United States|US]] food crops. Their calculations came up with a figure of US $14.6 billion in food crop value.

There has not been sufficient study to quantify the effects of pollinator decline on wild plants and wild life that depends on them for feed. Some plants on the endangered species list are endangered because they have lost their normal pollinators.

===Increasing public awareness===

The steady increase in beekeeper migration (for pollination service on agricultural crops) has masked the issue of pollinator decline from much public awareness, however sudden blocks to such migration could have catastrophic results on the US food supply.

==Possible explanations for pollinator decline==
===[[Pesticide misuse]]===

It is a label violation to apply most [[insecticide]]s on crops during bloom, or to allow the pesticide to drift to blooming weeds that bees are visiting. Yet such applications are frequently done, with little enforcement of the bee protection directions. Pesticide misuse has driven beekeepers out of business, but can affect native wild bees even worse, because they have no human to move or protect them.

[[Bumblebee]] populations are in jeopardy in [[cotton]]-growing areas, since they are dosed repeatedly when pesticide applicators apply insecticides on blooming cotton fields while the bees are foraging.

Widespread aerial applications for [[mosquito]]es, [[Drosophila|med-flies]], [[grasshopper]]s, [[gypsy moth]]s and other insects leaves no islands of safety where wild insect pollinators can reproduce and r
epopulate. One such program can reduce or [[Endangered arthropod|endanger pollinator populations]] for several years. 

Many homeowners feel that [[dandelion]]s and [[clover]] are weeds, that lawns should only be grass, and that they should be highly treated with pesticides. This makes a hostile environment for bees, [[butterfly|butterflies]] and other pollinators.

See articles:
* [[Endangered arthropod]]
* [[Imidacloprid effects on bee population]]
* [[Regent (insecticide)|Regent]]

===Rapid transfer of [[parasite]]s and [[disease]]s of pollinator species around the world===

Increased international commerce within modern times has moved [[Diseases of the honey bee|diseases]] such as American foulbrood and chalkbrood, and parasites such as [[varroa]] [[mite]]s, [[acarina]] mites, and the small African hive beetle to new areas of the world, causing much loss of bees in the areas where they do not have much resistance to these pests. [[Solenopsis invicta|Imported fire ants]] have decimated ground nesting bees in wide areas of the southern US.

===Loss of [[habitat (ecology)|habitat]] and [[forage]]===

The push to remove hedgerows and other "unproductive" land in some farm areas removes habitat and homes for wild bees. Large tractor mounted rotary mowers may make farms and roadsides look neater, but they remove bee habitat at the same time. Old crops such as [[sweet clover]] and [[buckwheat]], which were very good for bees have been disappearing. Urban and suburban development pave or build over former areas of pollinator habitat. 

Clearcut [[logging]], especially when mixed [[forest]]s are replaced by uniform age [[pine]] planting, causes serious loss of pollinators, by removing [[hardwood]] bloom that feeds bees early in the season, and by removing hollow trees used by feral honey bees, and dead stubs used by many solitary bees.

===Nectar corridors===

Migratory pollinators require a continuous supply of [[nectar source]]s to gain their energy requirements for the migration. In some areas development or agriculture has disrupted and broken up these traditional corridors, and the pollinators have to find alternative routes or discontinue migration. A good example is the endangered lesser long-nosed bat (''Leptonycteris curasoae'') which was formerly the main pollinator of a number of cactus species in southwestern United States. Its numbers have severely declined, in part due to disruption of the nector corridors that it formerly followed. Other migratory pollinators include [[monarch butterfly|monarch butterflies]] and some [[hummingbird]]s.

===Bee paranoia===

Bees are often viewed negatively by homeowners and other property owners.  A search for "[[carpenter bee]]s" on the Internet primarily yields information on removal rather than information regarding bees in a postive light.  Recent hysteria regarding [[killer bees]] has contributed to these views. Beekeepers find increased [[vandalism]] of their hives, more difficulty in finding locations for bee yards, and more people inclined to [[Lawsuit|sue]] the local beekeeper if they are stung, even if it is by a [[wasp|yellow jacket]].

===[[Light pollution]]===

Increasing use of outside artificial lights, which interfere with the navigational ability of many [[moth]] species, and is suspected of interference with [[bird migration|migratory birds]] may also impact pollination. Moths are important [[pollinator]]s of night blooming [[flower]]s and moth disorientation may reduce or eliminate the [[plant]]s ability to reproduce, thus leading to long term [[ecology|ecological]] effects. This is a new field and this [[List of environment topics|environmental issue]] needs further study.

==Solutions to pollinator decline==

The decline of pollinators is compensated to some extent by beekeepers becoming migratory, following the bloom northward in the spring from southern wintering locations. Migration may be for traditional [[honey]] crops, but increasingly is for [[contract]] pollination to supply the needs for growers of crops that require it.

===Conservation and restora
tion efforts===

Efforts are being made to sustain  pollinator diversity in agro- and natural eco-systems by some [[Environmental movement|environmental]] groups. Prairie restoration, establishment of wildlife preserves, and encouragement of diverse wildlife landscaping rather than monoculture lawns, are examples of ways to help pollinators.

===Use of alternative pollinators===

Honey bees are usually the most widely chosen insects in most managed pollination situations. However they are not the most efficient pollinators of some flowers. Alternative pollinators, such as for example, [[Alfalfa leafcutter bee|leafcutter]] and [[alkali bee]]s in alfalfa pollination and [[bumblebee]]s in greenhouses for tomatoes are used to augment and in some cases replace honey bees. A wide variety of other bees can be found in the environment that are [[specialist]] pollinators (some only using one plant species). However, most of these alternative insects' value as pollinators and their relationships with plants are as yet little known.

In the US, some think that other pollinators will in time replace the lost honey bees, blamed on [[invasive species|introduced]] acarine and varroa mites, but general pollinator decline was already happening before these entered the picture. Only in a few areas are wild populations of pollinators building up; in most areas they are declining as badly as honey bees.

Furthermore pollinators cannot be exchanged on a one-for-one basis. They are not all equal. Some are generalists, some are specialists. Some are brawny; some are feeble. Some have long tongues; some short. Some work at colder temperatures than others. Bees may deliberately collect pollen, but have different collection techniques, which can greatly affect their efficiency as pollinators. 

Flowers are frequently specifically [[Pollination syndrome|adapted to one pollinator]], or a small group of pollinators because of floral structure, color, odor, nectar guides, etc. Proposed alternative pollinators may not be physically capable of accomplishing pollination, or they may not be attracted to the flower of that plant species, or they may rob nectar by cutting sepals, thus avoiding pollination. Understanding the pollination needs of a species is vital to understanding of a plant species, yet this is often poorly understood. In horticulture it is critical to the economic success of the grower, and crops have sometimes been abandoned from general use in an area because of lack of understanding of pollinator needs.

==See also==

*[[Bees and toxic chemicals]]
*[[Colony Collapse Disorder]]
*[[Diseases of the honey bee]]
*[[Endangered arthropod]]
*[[Pesticide toxicity to bees]]
*[[Imidacloprid effects on bee population]]
*[[Regent (insecticide)]]

==References==

*''The Value of Honey Bees As Pollinators of U.S. Crops in 2000'', Drs. [[Roger Morse]] and Nicholas Calderone of [[Cornell University]] (2000) : [http://www.masterbeekeeper.org/pdf/pollination.pdf]
* ''The Forgotten Pollinators'' by Drs. Stephen L. Buchmann and [[Gary Paul Nabhan]] is a classic work describing the pollinator crisis. In the vein of [[Rachel Carson]], their opening chapter, "Silent Spring and Fruitless Falls" describes the risk in a nutshell. They go on to illustrate the problem and propose some solutions.
* ''Pollination, the Forgotten Agricultural Input'', Dr. Malcolm Sanford of the [[University of Florida]], published in Proceedings of the Florida Agricultural Conference and Trade Show, Lakeland, FL, September 29-30, 1998, J. Ferguson, et al eds., pp. 45-47. [http://apis.ifas.ufl.edu/papers/altpol.htm]
* ''Biological Diversity: Pollinators'' Science in Africa, Issue 2, Sun Jul 30 2006 [[United Nations]] [[Food and Agriculture Organization]] position paper on the subject of pollinator decline:   [http://www.scienceinafrica.co.za/pollinator.htm]
*''The International Initiative for the Conservation and Sustainable use of Pollinators:  A proposal for a plan of action'' Convention on biological diversity,  Montreal, 12-16 November 2001, [http://www.biodiv.org/doc/meetings/sbst
ta/sbstta-07/official/sbstta-07-09-add1-en.doc]
*''[[Xerces Society]] Pollinator Conservation Program''  2006 (North America) [http://www.xerces.org/Pollinator_Insect_Conservation/index.htm]
*''POLLINATOR BIODIVERSITY A CO-ORDINATED GLOBAL APPROACH'',   Eardley, C. 2001. Acta Hort. (ISHS) 561:331-332([[FAO]]) VIII International Symposium on Pollination - Pollination: Integrator of Crops and Native Plant Systems [http://www.actahort.org/books/561/561_50.htm]
*''The Economic Impacts of Pollinator Declines: An Approach to Assessing the Consequences'', Peter G. Kevan and Truman P. Phillips, [[Conservation Ecology]] v.5, i.1 June 2001  [http://www.mindfully.org/Farm/Pollinator-Declines.htm]
*''Brazilian Pollinators Initiative'', Vera Lucia Imperatriz Fonseca; Braulio Ferreira Souza Dias   [http://eco.ib.usp.br/beelab/bpi_ceara.pdf] accessed March 2004  ''THE SAO PAULO DECLARATION ON POLLINATORS'' [http://rgm.fmrp.usp.br/beescience/arquivospdf/workshop.pdf]
*''The Pollination Home Page'' [http://pollinator.com] US; accessed Jul 2006
*''The North America Pollinator Protection Campaign'' [http://www.nappc.org/]  [[Coevolution Institute]] US; accessed Jul 2006
*''Pollinator Conservation Handbook'' Xerces Society 2005, [http://www.xerces.org/pubs_merch/PCH.htm]
*''The Bumblebee Conservation Trust'' [http://www.bumblebeeconservationtrust.co.uk/] Great Britain; accessed Jul 2006
*''The impact of aerial fenitrothion spraying upon the population biology of bumble bees (Bombus Latr.: Hym.) in southwestern [[New Brunswick]]''. Plowright, R.C., B.A. Pendrel and I.A. McLaren. 1978. Canadian Entomology 110: 1145-1156. - A case study in the loss of pollination for blueberries, caused by gypsy moth spraying, which also killed bumblebees

[[Category:Ecology]]
[[Category:Insect ecology]]
[[Category:Beekeeping]]
[[Category:Environmental threats]]
[[Category:Pollination]]
[[Category:Bioindicators]]