Preface Pollination is one of the crucial ecosystem services. About 80% of the angiosperm species are dedicated on animal pollination, mostly by insect. In agricultural ecosystem, many agricultural crops are dependent on insects for their pollination, and assisted pollination may have to be done when natural pollination is insufficient in order to reduce potential yield loss. The economic value of the pollination services provided by insect pollinators in 2005 was estimated to be about €153 billion. The United Nations also reported on the economics of ecosystems and biodiversity that insect pollination was valued at £134 billion. There is the irony to ignore the precious insect pollinators and their service which is a key constraint to words the sustainability of contemporary agricultural practices. Pollinators belong to diverse groups of the animal kingdom, including birds, bat, reptiles, insects, etc. Many plants have evolved intricate relationships with many insect pollinators, without which majority of plant species would not reproduce and maintain their genetic diversity. Conservation of pollinator’s biodiversity is important for the potential yield of agricultural as well as horticultural crops and their hybrid seed production. Insect pollinators and other pollinators are declining at an alarming rate which has threatened the existence of plant life and this downward trend could damage dozens of commercially important crops. The decline in pollinators’ population and diversity is a serious concern for agricultural production, conservation and maintenance of biodiversity in many parts of the world. Conservation of pollinator’s biodiversity is important for the potential yield of agricultural as well as horticultural crops and their hybrid seed production. Encouragement of wild pollinators, domestication of unused potential pollinators and more environmentally, sensitive human exploitation of the world are needed as part of conservation, forestry, agro forestry, sustainable agriculture and development. For providence it is our need to conserve and as much as possible, proliferate the pollinators’ population till asymptote crosses the boundaries between agrarianism and land ethic, despite the fact that the values and goals of farmers and biodiversity conservationists are not always in synchrony with each other.

Pollination is one of the most essential ecosystem services which is effectual for crop productivity, biodiversity and human livelihood. Pollination is the process of transferring pollens from anther to stigma for plant reproduction and has direct impact on crop productivity. Conservation and management of pollinators is still ignored in the agriculture development program by the policy makers. In agricultural ecosystem, many agricultural crops are dependent on insects for their pollination, and assisted pollination may have to be done when natural pollination is insufficient in order to reduce potential yield loss (Klein et al., 2007). About 80% of the world’s flowering plant species are dedicated to animal pollination, mostly by insects (FAO, 2007). In 2005, globally, pollinators’ pollination services economic value was estimated to be about €153 billion (Gallai et al., 2009). The United Nations also reported that the economics of ecosystems and biodiversity by insect pollination was valued at £134 billion.

Introduction Pollination is a process in which pollen grains are transferred from male gametes to the female gamete, thereby enabling fertilization and reproduction through growth of the pollen tube and eventual release of sperm. Fertilization is the union of the egg and sperm. In plants, this may happen after pollination; however, pollination doesn’t always result in fertilization. Fertilization occurs when the pollen grains germinate on the stigma and grow in the style. Reproduction is the process to produce offspring by fusion of male and female gametes, which simply means that the sperms of the pollen unite with the ovules in the ovary of the flower and subsequently produce seed. Flowers may facilitate out-crossing (fusion of sperm and eggs from different individuals in a population) or allow selfing (fusion of sperm and egg from the same flower). Some flowers produce diasporas without fertilization (parthenocarpy).

Pollination is a vital and key component of ecosystem services which is provided by pollinators. FAO, 2007 reported that 80 per cent of plant species rely for pollination on pollinators, which is dominated by insects. Among the insect pollinators, solitary and social bees dominate both managed and natural ecosystems. No other groups of insects are more beneficial to humans than bees. Many plants have evolved intricate relationships with many insect pollinators and without their presence, majority of plant species would not reproduce and maintain their genetic diversity (Daily et al., 1997). In natural ecosystem, insect pollination plays a pivotal role to maintain and conserve the plant biodiversity. On a global scale, the total annual value of insect pollination services has been estimated at USD 217 billion (Sciencedaily, 2008). United Nations reported that the economics of ecosystems and biodiversity by insect pollination was valued at £134 billion.

The Colony Collapse Disorder (CCD) is not a disease; it is multi-factorial syndrome which causes massive losses of honey bee in the USA and elsewhere. It is recorded that in European honey bee (Apis mellifera). The adult worker bee population of the colony demean through catastrophic effects of CCD. The dwindling of adult worker bees in colonies and the lack of noticeable symptoms leads to the nebulous label of CCD. In this syndrome, dead worker bees cannot be found in the colony and their vicinity of bee hive, and stored food (honey and pollen) are not touched by robbers bees and combs remain as such for several weeks even after the collapse. Some scientists; Aizen and Harder, also reported this disorder is not universal and, in fact, global populations of honey bee (A. mellifera) populations are increasing. In the spring of 2007, beekeepers in the US reported a rare kind of bee colony disease where they die off and numerous colonies left their hives and disappeared without a trace. The plight of honey bee in USA has caused concern and attracted great attention of scientists to delve and provide explanations of this mystery and preventive measures. In US, it is also christened “Honey bee AIDS” by some popular media. Indeed, honey bee colonies can die in many ways and CCD is just one of them. Finally, since both honey bee host and pathogens are genetically diverse, the symptoms and causes of colony losses may well be different in varrious regions.

Pollination is a keystone process in both human managed and natural terrestrial ecosystems. Pollinators are an input of crop cultivation and associated biodiversity, and provide an essential ecosystem service to both natural and agro- ecosystems. In agro-ecosystems, management of pollinators can maximize the pollination and thereby enhance the crop productivity and yield quality. Pollination is the best example of mutualism between plant species and their pollinators which results into intricate relationships between plant and animal - the reduction or loss of either affecting the survival of both. Approximately 80 per cent of all flowering plant species are dedicated to pollination by animals and mostly by insects. The negative impact of pollinator deficit is strongly felt in reduction of fruit set seed productivity and agricultural biodiversity. The role of pollinators is transfer of pollen from anther to stigma of the same species to ensure reproduction, seed set, fruit set development and multiplication of plants, both in agro ecosystems and natural ecosystems.

Agricultural biodiversity is known as crop genetic resources, although agroecosystems hold a wide diversity of other organisms that contribute toward their productivity and sustainability. Amongst these pollinators play the massive role in crop pollination and thus ensure that fruit or seeds are formed. Over 3 decades ago, the international community began to emphasize on the importance of pollinators. In agro-ecosystems, pollinators are essential for agriculture, horticultural and forage production as well as the production of seed for many root and fiber crops. Pollinators such as bees, birds and bats affect 35 per cent of the world’s crop production, increasing outputs of 87 of the leading food crops worldwide, plus many plant-derived medicines in our pharmacies (Klein et al., 2007). Food security, food diversity, human nutrition and plant diversity all rely strongly on animal pollinators. Pollination is an essential ecosystem service that enables plant reproduction and food production. The pollinators’ abundance and diversity play pivotal role for enhancement of the productivity, quality and maintenance of natural resources of plant biodiversity. The diminution of pollination abundance and their diversity certainly affect productivity, quality and plant biodiversity.

Pollinators are organisms that help to transfer pollen from anther to stigma of the same species for fertilization and thereby produce seeds and fruits. Pollinators belong to diverse groups viz. insects, birds, reptiles, mammals, etc. Insects; bees butterflies, moths, wasps, flies, some types of beetles. Out of insect pollinators, bees are most important pollinator. Insect pollinators are critical to the production of many crops and play pivotal role to maintain the biodiversity. The decline in honeybee and other pollinator populations have more attention of scientific and public concern globally as well as in India. A number of factors have been observed as potential contributors to these declines and no single factor has been identified as the cause. The available science suggests that multiple factors responsible for population depletion and extinction, including loss of habitat and food sources, diseases, viruses, pests, and pesticide exposure. It is also known that certain pesticides can pose an immediate or “acute” threat to the insect pollinators and bees. In order to protect pollinators, the labels of pesticides that pose such risks should specify detailed directions of application to reduce potential exposure.

In agro-ecosystem, many agricultural and horticultural crops are dependent on insects for their pollination; their degree of interdependence varies species to species. Some plant species depend primarily on a single pollinator’s species or genus, whereas some plant species accept diverse pollinators. About to 80 per cent of flowering plants’ pollination determined for pollinators (FA0, 2007) and out of that most of the floras depend on insect pollinators for pollination and pollinators depend on flora for their food. Bees are considered as most important pollinator due to their diversity, credential ability and effective pollinators of many plant species. Most of the crops pollination need was met by wild pollinators living within the farming landscape (Kevan and Phillips, 2001). Therefore, pollinators play paramount role in ecosystem through enhance the crop productivity and conserving biodiversity. On the above service of pollinators is priceless and natural endowment, but the society we live in, always categorized and measured in terms of financial value. In 2005, globally, insect pollination services economic value was estimated to be about €153 billion (Gallai et al., 2009). The United Nations also reported that the economics of ecosystems and biodiversity by insect pollination was valued at £134 billion. The assisted pollination may have to be done when natural pollination is insufficient in order to reduce potential yield loss (Klein et al., 2007).

Pollinators provide an essential ecosystem service, namely pollination, and it is an intricate relationship between plants and animals where reduction or loss of either will affect the survival of both. It has been established that pollinating agents are essential for survival and reproduction of several wild plant species (Kearns et al., 1998). About 80% of the world’s flowering plant species are dedicated to animal pollination, mostly by insects (FA0, 2007). Although more than 750,000 insect pollinators have been described (Grimaldi and Engel, 2005), possibly as many as 30 million more await discovery and formal description (Erwin, 2004). In 2005, globally, pollinators’ pollination services economic value was estimated to be about €153 billion (Gallai et al., 2009). The United Nations also reported that the economics of ecosystems and biodiversity by insect pollination was valued at £134 billion. The depletion of insect pollinators is due to pollinators’ habitat destruction, heavy tillage, monoculture, injudicious use of pesticides and climate change and therefore, there is the need to create awareness on conservation and pollination management. Climate change is highly affected to species interaction as well as ecosystem ecology (van-der-Putten et al., 2004; Sutherst et al., 2007). Plant-pollinator interaction in both wild and cultivated plant species is under threat (Biesmeijer et al., 2006).

Approximately 80 per cent of all flowering plant species are specialized for pollination by animals and mostly by insects. These crops account for 65 per cent of global food production, still leaving as much as 35 per cent depending on pollinating animals (Klein et al., 2007). These food crops include delicious products such as many of our tree fruits (e.g., apples, cherries, mangos, and avocados) and nuts (e.g., almonds, peanuts, macadamia nuts, and cashew nut), squashes, cucumbers, melons, citrus, and berries. In addition, many of oil seed crops benefit from bee pollination, such as mustard, coconut, canola, safflower, and many more. The honey bee (Apis mellifera) is the most commonly used insect in agricultural crops as managed pollinator in North America and Europe, Japan, China, India and many other parts of the world as well. Farmers in the United States rent more than 2.5 million honey bee colonies every year for fulfillment of pollination deficit but today, the honey bee is threatened by colony collapse disorder (CCD). The demand for honey bees in California almond orchards rapidly increased due to increasing acreage, while on the other side, bee colonies decreased due to CCD, but that occurred during a time when honey bee colonies were not easy to procure and as a result, the cost of renting bees shot up from US$50 per hive in 2003 to US$140 per hive in 2006 (Sumner and Boriss, 2006). The rental charge increased about 3 times within 4 years.

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