Pollinator - AbsoluteAstronomy.com

A pollinator is the biotic agent (vector) that moves pollen

Pollen

Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...

from the male anthers of a flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

to the female stigma of a flower to accomplish fertilization or syngamy of the female gamete

Gamete

A gamete is a cell that fuses with another cell during fertilization in organisms that reproduce sexually...

in the ovule

Ovule

Ovule means "small egg". In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: The integument forming its outer layer, the nucellus , and the megaspore-derived female gametophyte in its center...

of the flower by the male gamete from the pollen grain. Though the terms are sometimes confused, a pollinator is different from a pollenizer

Pollenizer

A pollenizer or polleniser, sometimes pollinizer or polliniser is a plant that provides pollen.In American English, the words pollenizer and pollinator are often confused: A pollinator is the biotic agent that moves the pollen, such as bees, moths, bats, and birds...

, which is a plant that is a source of pollen for the pollination

Pollination

Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...

process.

Background

Plants fall into pollination syndrome

Pollination syndrome

Pollination syndromes are suites of flower traits that have evolved in response to natural selection imposed by different pollen vectors, which can be abiotic or biotic, such as birds, bees, flies, and so forth. These traits include flower shape, size, colour, odour, reward type and amount, nectar...

s that reflect the type of pollinator being attracted. These are characteristics such as: overall flower size, the depth and width of the corolla, the color (including patterns called nectar guides that are visible only in ultraviolet

Ultraviolet

Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

light), the scent

Odor

An odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors...

, amount of nectar, composition of nectar, etc. For example, birds visit red flowers with long narrow tubes and lots of nectar, but are not as strongly attracted to wide flowers with little nectar and copious pollen, which are more attractive to beetles. When these characteristics are experimentally modified (altering colour, size, orientation), pollinator visitation may decline.

Bees

The most recognized pollinators are the various species of bee

Bee

Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...

s, which are plainly adapted to pollination. Bees typically are fuzzy and carry an electrostatic charge. Both features help pollen grains adhere to their bodies, but they also have specialized pollen-carrying structures; in most bees, this takes the form of a structure known as the scopa

Scopa (biology)

The term scopa is used to refer to any of a number of different modifications on the body of a non-parasitic bee that form a pollen-carrying apparatus. In most bees, the scopa is simply a particularly dense mass of elongated, often branched, hairs on the hind leg...

, which is on the hind legs of most bees, and/or the lower abdomen (e.g., of megachilid

Megachilidae

The Megachilidae are a cosmopolitan family of solitary bees whose pollen-carrying structure is restricted to the ventral surface of the abdomen...

bees), made up of thick, plumose seta

Seta

Seta is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms.-Animal setae:In zoology, most "setae" occur in invertebrates....

e. Honey bee

Honey bee

Honey bees are a subset of bees in the genus Apis, primarily distinguished by the production and storage of honey and the construction of perennial, colonial nests out of wax. Honey bees are the only extant members of the tribe Apini, all in the genus Apis...

s, bumblebee

Bumblebee

A bumble bee is any member of the bee genus Bombus, in the family Apidae. There are over 250 known species, existing primarily in the Northern Hemisphere although they are common in New Zealand and in the Australian state of Tasmania.Bumble bees are social insects that are characterised by black...

s, and their relatives do not have a scopa, but the hind leg is modified into a structure called the corbicula (also known as the "pollen basket

Pollen basket

The pollen basket or corbicula is part of the tibia on the hind legs of the four related lineages of apid bees that used to comprise the family Apidae: the honey bees, bumblebees, stingless bees, and orchid bees...

"). Most bees gather nectar, a concentrated energy source, and pollen, which is high protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

food, to nurture their young, and inadvertently transfer some among the flowers as they are working. Euglossine

Euglossini

Euglossine bees, also called orchid bees, are the only group of corbiculate bees whose non-parasitic members do not all possess eusocial behavior. Most of the species are solitary, though a few are communal, or exhibit simple forms of eusociality...

bees pollinate orchids, but these are male bees collecting floral scents rather than females gathering nectar or pollen. Female orchid bees act as pollinators, but of flowers other than orchids. Eusocial bees such as honey bees need an abundant and steady source of pollen

Pollen source

The term pollen source is often used in the context of beekeeping and refers to flowering plants as a source of pollen for bees or other insects. Bees collect pollen as a protein source to raise their brood. For the plant, the pollinizer, this can be an important mechanism for sexual reproduction,...

to multiply.

Honey bees

Honey bee

s travel from flower to flower, collecting nectar (later converted to honey

Honey

Honey is a sweet food made by bees using nectar from flowers. The variety produced by honey bees is the one most commonly referred to and is the type of honey collected by beekeepers and consumed by humans...

), and pollen grains. The bee collects the pollen by rubbing against the anthers. The pollen collects on the hind legs, in a structure referred to as a "pollen basket

Pollen basket

". As the bee flies from flower to flower, some of the pollen grains are transferred onto the stigma of other flowers.

Nectar provides the energy for bee nutrition

Nutrition

Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....

; pollen provides the protein

Protein

. When bees are rearing large quantities of brood (beekeepers say hives are "building"), bees deliberately gather pollen to meet the nutritional needs of the brood. A honey bee that is deliberately gathering pollen is up to ten times more efficient as a pollinator than one that is primarily gathering nectar and only unintentionally transferring pollen.

Good pollination management seeks to have bees in a "building" state during the bloom period of the crop, thus requiring them to gather pollen, and making them more efficient pollinators. Thus the management techniques of a beekeeper

Beekeeper

A beekeeper is a person who keeps honey bees for the purposes of securing commodities such as honey, beeswax, pollen, royal jelly; pollinating fruits and vegetables; raising queens and bees for sale to other farmers; and/or for purposes satisfying natural scientific curiosity...

providing pollination services are different from, and to some extent in tension with, those of a beekeeper who is trying to produce honey.

Millions of hives

Beehive (beekeeping)

A beehive is an enclosed structure in which some honey bee species of the subgenus Apis live and raise their young. Natural beehives are naturally occurring structures occupied by honeybee colonies, while domesticated honeybees live in man-made beehives, often in an apiary. These man-made...

of honey bees are contract

Contract

A contract is an agreement entered into by two parties or more with the intention of creating a legal obligation, which may have elements in writing. Contracts can be made orally. The remedy for breach of contract can be "damages" or compensation of money. In equity, the remedy can be specific...

ed out as pollinators by beekeepers

Beekeeping

Beekeeping is the maintenance of honey bee colonies, commonly in hives, by humans. A beekeeper keeps bees in order to collect honey and other products of the hive , to pollinate crops, or to produce bees for sale to other beekeepers...

, and honey bees are by far the most important commercial pollinating agents, but many other kinds of pollinators, from bluebottle flies, to bumblebees, orchard mason bee

Orchard mason bee

Osmia lignaria, commonly known as the orchard mason bee or blue orchard bee, is a megachilid bee that makes nests in reeds and natural holes, creating individual cells for their brood that are separated by mud dividers. Unlike carpenter bees, they cannot drill holes in wood. O...

s, and leaf cutter bees

Alfalfa leafcutter bee

Megachile rotundata, the alfalfa leafcutter bee or lucerne leafcutter bee is a European bee that has been introduced to other regions...

are cultured and sold for managed pollination

Pollination management

Pollination Management is the label for horticultural practices that accomplish or enhance pollination of a crop, to improve yield or quality, by understanding of the particular crop's pollination needs, and by knowledgeable management of pollenizers, pollinators, and pollination...

.

Other species of bees differ in various details of their behavior and pollen-gathering habits, and it should be remembered that honey bees are not native to the Western Hemisphere

Western Hemisphere

The Western Hemisphere or western hemisphere is mainly used as a geographical term for the half of the Earth that lies west of the Prime Meridian and east of the Antimeridian , the other half being called the Eastern Hemisphere.In this sense, the western hemisphere consists of the western portions...

; all pollination of native plants in the Americas has been historically performed by various native bees.

Other insects

Lepidoptera

Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

(butterflies

Butterfly

A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured...

and moth

Moth

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

s) also pollinate to a small degree. They are not major pollinators of our food crops, but various moths are important for some wildflowers, or other commercial crops such as tobacco

Tobacco

Tobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...

.

Many other insects accomplish pollination. Wasp

Wasp

The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...

s (esp. Sphecidae

Sphecidae

Sphecidae is a cosmopolitan family of wasps that include digger wasps, mud daubers and other familiar types that all fall under the category of thread-waisted wasps.The are predominently solitary wasp,distributed world wide.At present this family consist of eight subfamilies and three tribes...

and Vespidae), bombyliid flies

Bombyliidae

Bombyliidae is a large family of flies with hundreds of genera, although their life cycles are not well known. Adults generally feed on nectar and pollen, thus are pollinators of flowers. They superficially resemble bees, thus are commonly called bee flies, and this may offer the adults some...

and syrphid flies are important pollinators of some plants. Beetle

Beetle

Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...

s, midge

Midge

A midge is a very small, two-winged flying insect. "Midge" may also refer to:-Real:* Midge Costanza , American politician* Mildred Gillars , aka "Midge", American broadcaster of Nazi propaganda during World War II...

s, and even thrips or ant

Ant

Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...

s can sometimes pollinate flowers. Green bottle

Green bottle fly

The common green bottle fly is a common blow-fly found in most areas of the world, and the most well-known of the numerous green bottle fly species. It is 10–14 mm long, slightly larger than a housefly, and has brilliant, metallic, blue-green or golden coloration with black markings. It has...

or carrion flies are important for some flowers, usually ones that exude a fetid odor

Carrion flower

Carrion flowers or stinking flowers are flowers that emit an odor that smells like rotting flesh. Carrion flowers attract mostly scavenging flies and beetles as pollinators. Some species may trap the insects temporarily to ensure the gathering and transfer of pollen.- Amorphophallus :Many plants in...

. Some male Bactrocera
Bactrocera
Bactrocera is a large genus of tephritid fruit flies, with more than 500 species currently described.-Name:The genus name is derived from Ancient Greek bakter "rod" and kera "horn".-Systematics:Many subgenera are defined within this...

fruit flies are exclusive pollinators of some wild Bulbophyllum
Bulbophyllum
Bulbophyllum is the largest genus in the orchid family Orchidaceae. With more than 2,000 species, it is also one of the largest genera of flowering plants, exceeded only by Astragalus...

orchids that have a specific chemical attractant present in their floral fragrance. Some Diptera

Diptera

Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...

(flies) may be the main pollinators in higher elevations of mountains whereas Bombus species are the only pollinators among Apoidea in alpine regions at timberline and beyond. Other insect orders are rarely pollinators, and then typically only accidentally (e.g., Hemiptera

Hemiptera

Hemiptera is an order of insects most often known as the true bugs , comprising around 50,000–80,000 species of cicadas, aphids, planthoppers, leafhoppers, shield bugs, and others...

such as Anthocoridae

Anthocoridae

The Anthocoridae are a family of bugs, commonly called minute pirate bugs or flower bugs.-Name:The vernacular name probably stems from the notion that these very small animals can do much pain to humans, just like small pirate vessels can do so to big ships.The scientific name is a combination of...

, Miridae

Miridae

The large and diverse insect family Miridae contains the plant bugs, leaf bugs, and grass bugs, and may also be known as capsid bugs. It is the largest family of true bugs belonging to the suborder Heteroptera, with over 10,000 known species and new ones constantly being described...

)

Vertebrates

Bats are important pollinators of some tropical flowers. Birds, particularly hummingbird

Hummingbird

Hummingbirds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird. They can hover in mid-air by rapidly flapping their wings...

s, honeyeaters and sunbirds also accomplish much pollination, especially of deep-throated flowers. Other vertebrates, such as monkey

Monkey

A monkey is a primate, either an Old World monkey or a New World monkey. There are about 260 known living species of monkey. Many are arboreal, although there are species that live primarily on the ground, such as baboons. Monkeys are generally considered to be intelligent. Unlike apes, monkeys...

s, lemur

Lemur

Lemurs are a clade of strepsirrhine primates endemic to the island of Madagascar. They are named after the lemures of Roman mythology due to the ghostly vocalizations, reflective eyes, and the nocturnal habits of some species...

s, possum

Possum

A possum is any of about 70 small to medium-sized arboreal marsupial species native to Australia, New Guinea, and Sulawesi .Possums are quadrupedal diprotodont marsupials with long tails...

s, rodent

Rodent

Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

s and lizard

Lizard

Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...

s have been recorded pollinating some plants.

Humans can be pollinators, as many gardeners have discovered that they must hand pollinate

Hand pollination

Hand pollination is a technique used when natural, or open pollination is insufficient or undesirable. The most common techniques are for crops such as cucurbits, which may exhibit poor pollination by fruit abortion, fruit deformity or poor maturation...

garden vegetable

Vegetable

The noun vegetable usually means an edible plant or part of a plant other than a sweet fruit or seed. This typically means the leaf, stem, or root of a plant....

s, whether because of pollinator decline

Pollinator decline

The term pollinator decline refers to the reduction in abundance of pollinators in many ecosystems worldwide during the end of the twentieth century....

(as has been occurring in parts of the U.S. since the mid-20th century) or simply to keep a strain genetically pure. This can involve using a small brush or cotton

Cotton

Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....

swab to move pollen, or to simply tap or shake tomato

Tomato

The word "tomato" may refer to the plant or the edible, typically red, fruit which it bears. Originating in South America, the tomato was spread around the world following the Spanish colonization of the Americas, and its many varieties are now widely grown, often in greenhouses in cooler...

blossoms to release the pollen for the self pollinating flowers. Tomato blossoms are self fertile, but (with the exception of potato-leaf varieties) have the pollen inside the anther, and the flower requires shaking to release the pollen through pores. This can be done by wind, by humans, or by a sonicating

Buzz pollination

Sonication or buzz pollination is a technique used by some bees to release pollen which is more or less firmly held by the anthers, which makes pollination more efficient. The anther of buzz-pollinated species of plants is typically tubular, with an opening at only one end, and the pollen is inside...

bee (one that vibrates its wing muscles while perched on the flower), such as a bumblebee. Sonicating bees are extremely efficient pollinators of tomatoes, and colonies of bumblebees are quickly replacing humans as the primary pollinators for greenhouse

Greenhouse

A greenhouse is a building in which plants are grown. These structures range in size from small sheds to very large buildings...

tomatoes.

Pollinator population declines and conservation

In 1999 the Convention on Biological Diversity issued the São Paulo Declaration on Pollinators, recognizing the critical role that these species play in supporting and maintaining terrestrial productivity as well as the survival challenges they face due to anthropogenic change. Today pollinators are considered to be in a state of decline; some species, such as Franklin’s bumble bee (Bombus franklini) have been red-listed and are in danger of extinction.

Declines in the health and population of pollinators pose what could be a significant threat to the integrity of biodiversity, to global food webs, and to human health. At least 80% of our world's crop species require pollination to set seed. An estimated one out of every three bites of food comes to us through the work of animal pollinators.

External links

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