Pollen beetle

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Pollen beetle is an informal term for any species of beetle associated intimately with suitably pollen-rich species of flowers. Typically such a beetle is adapted to the pollen as a major part of its diet. Species in at least sixteen families of the order Coleoptera could be counted as pollen beetles, [1] [2] and "pollen beetle" also is a common name for some such species.

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Pollen feeding

Many insects of small to modest size benefit from feeding on pollen of suitable plants; pollen tends to be rich in protein, plentiful in season and easily available. Many plants, such as some members of the Araceae and Zamiaceae, produce large amounts of nutritious pollen, while producing little or no nectar. The pollen of such plants attracts and nourishes specialist pollen feeders that perform pollination, and many of those pollen feeders are beetles. In accessing the pollen of such plants, many pollen-feeding insects form mutually beneficial ecological relationships. Others damage the flowers however, reducing seed set, and harming the crop rather than benefiting it.

The nutritious Pollen from plants adapted to such pollinators contrasts with the also copious pollen from specialist anemophilous plants. Strict anemophiles commonly produce pollen that is low in nutritive value, since it is not adapted to attract or feed pollinators. Furthermore, as an adaptation to being borne effectively by the wind, anemophilous pollen must be very light.

More specifically than speaking loosely of "pollen beetles" as a common name the expression is the common name for certain species of beetle in particular, mainly a few members of the families Melyridae, Nitidulidae and Oedemeridae. However, there are many others that, though not commonly called "pollen beetles", do feed avidly on pollen, including species in the following: [2]

Pollen beetles in the Melyridae

Astylus atromaculatus Astylus atromaculatus Coetze4.jpg
Astylus atromaculatus

Among the Melyridae the most prominent example of a species commonly referred to as a pollen beetle is Astylus atromaculatus . It feeds particularly on the large amounts of pollen produced by members of the grass family Poaceae, and related wind-pollinated families such as the Cyperaceae. It does however also visit many other flowers, such as members of the Asteraceae. It is not clear whether it causes more harm to crops by eating pollen and young tissues than it does good by promoting pollination.

Another species of "pollen beetle" in the family Melyridae is Dicranolaius bellulus . It is more of a predator than say, Astylus species, and is accordingly valued as an agent in pest management programs, but pollen is a major part of its diet. [3] [4]

Pollen beetles in the Nitidulidae

Meligethes aeneus Meligethes.aeneus.-.lindsey.jpg
Meligethes aeneus

Several members of the Nitidulidae are similarly referred to as pollen beetles. In particular, practically all the species in the genus Meligethes are called pollen beetles. Of these the most notorious is probably the one now accepted as being properly called Meligethes aeneus/Brassicogethes aeneus. It is called the "Brassica pollen beetle", "Rape pollen beetle" and similar names, because it first became prominent as a pest of such crops in the first quarter of the 20th century. [5]

Pollen beetles in the Oedemeridae

Oedemera simplex Beetle May 2009-3.jpg
Oedemera simplex

Many species in the family Oedemeridae are similarly called "pollen beetles". For example, the Southern Pollen Beetle in the United States is Oxycopis notoxoides ). [6]

See also

Related Research Articles

Pollen The grains containing the male gametophytes of seed plants

Pollen is a powdery substance consisting of pollen grains which are male microgametophytes of seed plants, which produce male gametes. Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of coniferous plants. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics. Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anther of a flower to the stigma of the same flower.

Pollinator

A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains.

Hoverfly Insect

Hoverflies, also called flower flies or syrphid flies, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, while the larvae (maggots) eat a wide range of foods. In some species, the larvae are saprotrophs, eating decaying plant and animal matter in the soil or in ponds and streams. In other species, the larvae are insectivores and prey on aphids, thrips, and other plant-sucking insects.

Pollination Biological processes occurring in plants

Pollination is the transfer of pollen from a male part of a plant to a female part of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents are animals such as insects, birds, and bats; water; wind; and even plants themselves, when self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species it can produce hybrid offspring in nature and in plant breeding work.

Thrips Order of insects

Thrips are minute, slender insects with fringed wings and unique asymmetrical mouthparts. Different thrips species feed mostly on plants by puncturing and sucking up the contents, although a few are predators. Entomologists have described approximately 6,000 species. They fly only weakly and their feathery wings are unsuitable for conventional flight; instead, thrips exploit an unusual mechanism, clap and fling, to create lift using an unsteady circulation pattern with transient vortices near the wings.

A nectar source is a flowering plant that produces nectar as part of its reproductive strategy. These plants create nectar, which attract pollinating insects and sometimes other animals such as birds.

Buzz pollination

Buzz pollination or sonication is a technique used by some bees, such as solitary bees to release pollen which is more or less firmly held by the anthers. The anthers of buzz-pollinated plant species are typically tubular, with an opening at only one end, and the pollen inside is smooth-grained and firmly attached. With self-fertile plants such as tomatoes, wind may be sufficient to shake loose the pollen through pores in the anther and accomplish pollination. Visits by bees may also shake loose some pollen, but more efficient pollination of those plants is accomplished by a few insect species who specialize in sonication or buzz pollination.

Anemophily Wind pollination

Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind. Almost all gymnosperms are anemophilous, as are many plants in the order Poales, including grasses, sedges, and rushes. Other common anemophilous plants are oaks, pecans, pistachios, sweet chestnuts, alders and members of the family Juglandaceae. Approximately 12% of plants across the globe are benefited by anemophily, including cereal crops like rice and corn and other prominent crop plants like wheat, rye, barley, and oats. In addition, many pines, spruces, and firs are wind-pollinated, and people rely on these hardwood trees for their survival.

Entomophily Form of pollination by insects

Entomophily or insect pollination is a form of pollination whereby pollen of plants, especially but not only of flowering plants, is distributed by insects. Flowers pollinated by insects typically advertise themselves with bright colours, sometimes with conspicuous patterns leading to rewards of pollen and nectar; they may also have an attractive scent which in some cases mimics insect pheromones. Insect pollinators such as bees have adaptations for their role, such as lapping or sucking mouthparts to take in nectar, and in some species also pollen baskets on their hind legs. This required the coevolution of insects and flowering plants in the development of pollination behaviour by the insects and pollination mechanisms by the flowers, benefiting both groups.

Zoophily

Zoophily is a form of pollination whereby pollen is transferred by animals, usually by invertebrates but in some cases vertebrates, particularly birds and bats, but also by other animals. Zoophilous species frequently have evolved mechanisms to make themselves more appealing to the particular type of pollinator, e.g. brightly colored or scented flowers, nectar, and appealing shapes and patterns. These plant-animal relationships are often mutually beneficial because of the food source provided in exchange for pollination.

In agriculture and gardening, a beneficial organism is any organism that benefits the growing process, including insects, arachnids, other animals, plants, bacteria, fungi, viruses, and nematodes. Benefits include pest control, pollination, and maintenance of soil health. The opposite of beneficial organisms are pests, which are organisms deemed detrimental to the growing process. There are many different types of beneficial organisms as well as beneficial microorganisms. Also, microorganisms have things like salt and sugar in them. Beneficial organisms include but are not limited to: Birds, Bears, Nematodes, Insects, Arachnids, and fungi. The ways that birds and bears are considered beneficial is mainly because they consume seeds from plant and spread them through feces. Birds also prey on certain insects that eat plants and hinder them from growing these insects are known as non beneficial organisms. Nematodes are considered beneficial because they will help compost and provide nutrients for the soil the plants are growing in. Insects and arachnids help the growing process because they prey on non beneficial organisms that consume plants for food. Fungi help the growing process by using long threads of mycelium that can reach very long distances away from the tree or plant and bring water and nutrients back to the tree or plant roots.

Flower Structure found in some plants; aka: blossom

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 facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may facilitate outcrossing resulting from cross pollination or allow selfing when self pollination occurs.

Oedemeridae Family of beetles

The family Oedemeridae is a cosmopolitan group of beetles commonly known as false blister beetles, though some recent authors have coined the name pollen-feeding beetles. There are some 100 genera and 1,500 species in the family, mostly associated with rotting wood as larvae, though adults are quite common on flowers. The family was erected by Pierre André Latreille in 1810.

Palynivore Group of herbivorous animals

In zoology, a palynivore /pəˈlɪnəvɔːɹ/, meaning "pollen eater" is an herbivorous animal which selectively eats the nutrient-rich pollen produced by angiosperms and gymnosperms. Most true palynivores are insects or mites. The category in its strictest application includes most bees, and a few kinds of wasps, as pollen is often the only solid food consumed by all life stages in these insects. However, the category can be extended to include more diverse species. For example, palynivorous mites and thrips typically feed on the liquid content of the pollen grains without actually consuming the exine, or the solid portion of the grain. Additionally, the list is expanded greatly if one takes into consideration species where either the larval or adult stage feeds on pollen, but not both. There are other wasps which are in this category, as well as many beetles, flies, butterflies, and moths. One such example of a bee species that only consumes pollen in its larval stage is the Apis mellifera carnica. There is a vast array of insects that will feed opportunistically on pollen, as will various birds, orb-weaving spiders and other nectarivores.

Cleridae Checkered beetles

Cleridae are a family of beetles of the superfamily Cleroidea. They are commonly known as checkered beetles. The family Cleridae has a worldwide distribution, and a variety of habitats and feeding preferences.

Diptera is an order of winged insects commonly known as flies. Diptera, which are one of the most successful groups of organisms on Earth, are very diverse biologically. None are truly marine but they occupy virtually every terrestrial niche. Many have co-evolved in association with plants and animals. The Diptera are a very significant group in the decomposition and degeneration of plant and animal matter, are instrumental in the breakdown and release of nutrients back into the soil, and whose larvae supplement the diet of higher agrarian organisms. They are also an important component in food chains.

Mimicry in plants

In evolutionary biology, mimicry in plants is where a plant organism evolves to resemble another organism physically or chemically, increasing the mimic's Darwinian fitness. Mimicry in plants has been studied far less than mimicry in animals, with fewer documented cases and peer-reviewed studies. However, it may provide protection against herbivory, or may deceptively encourage mutualists, like pollinators, to provide a service without offering a reward in return.

<i>Astylus atromaculatus</i> Species of beetle

Astylus atromaculatus is a species of beetle in the family Melyridae. It is variously known as the spotted maize beetle, or pollen beetle. It is indigenous to Argentina and neighbouring countries, but has been accidentally imported into various other regions such as the warmer regions of North America and much of Africa, where it has become invasive.

<i>Brassicogethes aeneus</i> Species of beetle

Brassicogethes aeneus, known generally as common pollen beetle, is a species of pollen beetle in the family Nitidulidae. Other common names include the rape pollen beetle and rape blossom beetle. It was previously known as Meligethes aeneus.

Protea pruinosa, also known as frosted sugarbush or burnished protea, is a flowering shrub which belongs to the genus Protea within the botanical family Proteaceae. The plant is endemic to the southwestern Cape Region of South Africa.

References

  1. McCall, Andrew C & Irwin, Rebecca E. Florivory: the intersection of pollination and Herbivory. Ecology Letters, (2006) 9: 1351–1365 doi: 10.1111/j.1461-0248.2006.00975.x
  2. 1 2 "Pollen Use in Insects". ag.arizona.edu. Retrieved 5 March 2018.
  3. Chew, Peter. "Red and Blue Beetle, Pollen Beetle - Dicranolaius bellulus". www.brisbaneinsects.com. Retrieved 5 March 2018.
  4. "Red and Blue Pollen Beetle". www.padil.gov.au. Retrieved 5 March 2018.
  5. Kirton agricultural institute, Lincolnshire, England (1923). Annual Report ... "Guardian" printing works.CS1 maint: multiple names: authors list (link)
  6. Ross H. Arnett Jr. (28 July 2000). American Insects: A Handbook of the Insects of America North of Mexico, Second Edition. CRC Press. pp. 18–. ISBN   978-0-8493-0212-1.