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A pest is any animal or plant harmful to humans or human concerns. The term is particularly used for creatures that damage crops, livestock, and forestry or cause a nuisance to people, especially in their homes. Humans have modified the environment for their own purposes and are intolerant of other creatures occupying the same space when their activities impact adversely on human objectives. Thus, an elephant is unobjectionable in its natural habitat but a pest when it tramples crops. Some animals are disliked because they bite or sting; snakes, wasps,
ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22,0 ...
s,
bed bug Bed bugs are insects from the genus ''Cimex'' that feed on blood, usually at night. Their bites can result in a number of health impacts including skin rashes, psychological effects, and allergic symptoms. Bed bug bites may lead to skin changes ...
s, fleas and
tick Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...
s belong in this category. Others enter the home; these include houseflies, which land on and contaminate food, beetles, which tunnel into the woodwork, and other animals that scuttle about on the floor at night, like
cockroach Cockroaches (or roaches) are a paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. About 30 cockroach species out of 4,600 are associated with human habitats. Some species are well-known as ...
es, which are often associated with unsanitary conditions. Agricultural and horticultural crops are attacked by a wide variety of pests, the most important being insects, mites,
nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant- parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a bro ...
s and gastropod molluscs. The damage they do results both from the direct injury they cause to the plants and from the indirect consequences of the fungal, bacterial or viral infections they transmit. Plants have their own defences against these attacks but these may be overwhelmed, especially in habitats where the plants are already stressed, or where the pests have been accidentally introduced and may have no natural enemies. The pests affecting trees are predominantly insects, and many of these have also been introduced inadvertently and lack natural enemies, and some have transmitted novel fungal diseases with devastating results. Humans have traditionally performed
pest control Pest control is the regulation or management of a species defined as a pest; any animal, plant or fungus that impacts adversely on human activities or environment. The human response depends on the importance of the damage done and will range ...
in agriculture and forestry by the use of pesticides; however, other methods exist such as mechanical control, and recently developed
biological controls Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also invo ...
.


Concept

A pest is any living thing, whether animal, plant, or fungus, which humans consider troublesome to themselves, their possessions, or the environment. It is a loose concept, as an organism can be a pest in one setting but beneficial, domesticated, or acceptable in another. Microorganisms, whether bacteria, microscopic fungi,
protist A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exclu ...
s, or viruses that cause trouble, on the other hand, are generally thought of as causes of disease ( pathogens) rather than as pests. An older usage of the word "pest" is of a deadly
epidemic An epidemic (from Greek ἐπί ''epi'' "upon or above" and δῆμος ''demos'' "people") is the rapid spread of disease to a large number of patients among a given population within an area in a short period of time. Epidemics of infectious d ...
disease, specifically
plague Plague or The Plague may refer to: Agriculture, fauna, and medicine *Plague (disease), a disease caused by ''Yersinia pestis'' * An epidemic of infectious disease (medical or agricultural) * A pandemic caused by such a disease * A swarm of pes ...
. In its broadest sense, a pest is a competitor to humanity.


Animals as pests

Animals are considered pests or vermin when they injure people or damage crops, forestry, or buildings. Elephants are regarded as pests by the farmers whose crops they raid and trample. Mosquitoes and
tick Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...
s are vectors that can transmit ailments but are also pests because of the distress caused by their bites. Grasshoppers are usually solitary herbivores of little economic importance until the conditions are met for them to enter a swarming phase, become locusts and cause enormous damage. Many people appreciate birds in the countryside and their gardens, but when these accumulate in large masses, they can be a nuisance. Flocks of
starlings Starlings are small to medium-sized passerine birds in the family Sturnidae. The Sturnidae are named for the genus '' Sturnus'', which in turn comes from the Latin word for starling, ''sturnus''. Many Asian species, particularly the larger ones, ...
can consist of hundreds of thousands of individual birds, their roosts can be noisy and their droppings voluminous; the droppings are acidic and can cause corrosion of metals, stonework, and brickwork as well as being unsightly.
Pigeons Columbidae () is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They primarily ...
in urban settings may be a health hazard, and gulls near the coast can become a nuisance, especially if they become bold enough to snatch food from passers-by. All birds are a risk at airfields where they can be sucked into aircraft engines. Woodpeckers sometimes excavate holes in buildings, fencing and utility poles, causing structural damage; they also drum on various reverberatory structures on buildings such as gutters, down-spouts, chimneys, vents and aluminium sheeting. Jellyfish can form vast swarms which may be responsible for damage to fishing gear, and sometimes clog the cooling systems of power and desalination plants which draw their water from the sea. Many of the animals that we regard as pests live in our homes. Before humans built dwellings, these creatures lived in the wider environment, but co-evolved with humans, adapting to the warm, sheltered conditions that a house provides, the wooden timbers, the furnishings, the food supplies and the rubbish dumps. Many no longer exist as free-living organisms in the outside world, and can therefore be considered to be domesticated. The
St Kilda house mouse The St Kilda house mouse (''Mus musculus muralis'') is an extinct subspecies of the house mouse found only on the islands of the St Kilda archipelago of northwest Scotland. They were first described, alongside the St Kilda field mouse, by natu ...
rapidly became extinct when the last islander left the island of St Kilda, Scotland in 1930, but the
St Kilda field mouse The St Kilda field mouse (''Apodemus sylvaticus hirtensis'') is a subspecies of the wood mouse that is endemic to the Scottish archipelago of St Kilda, the island west of Benbecula in the Outer Hebrides, and from mainland Scotland. Unique t ...
survived.


Plants as pests

Plants may be considered pests, for example, if they are invasive species or weeds. There is no universal definition of what makes a plant a pest. Some governments, such as that of Western Australia, permit their authorities to prescribe as a pest plant "any plant that, in the local government authority's opinion, is likely to adversely affect the environment of the district, the value of property in the district, or the health, comfort or convenience of the district’s inhabitants." An example of such a plant prescribed under this regulation is caltrop, '' Tribulus terrestris'', which can cause poisoning in sheep and goats, but is mainly a nuisance around buildings, roadsides and recreation areas because of its uncomfortably sharp spiny
burr Burr may refer to: Places * Burr (crater), on the Jovian moon Callisto * Burr, Minnesota, an unincorporated community, United States * Burr, Missouri, an unincorporated community, United States * Burr, Nebraska, a village, United States * Burr, ...
s.


Other organisms as pests

Some definitions encompass any hazardous or problematic organism, and so often include fungi,
oomycete Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the resul ...
s, bacteria, and viruses.


Ecology

The term "plant pest", mainly applied to insect
micropredator Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...
s of plants, has a specific definition in terms of the
International Plant Protection Convention The International Plant Protection Convention (IPPC) is a 1951 multilateral treaty overseen by the United Nations Food and Agriculture Organization that aims to secure coordinated, effective action to prevent and to control the introduction an ...
and phytosanitary measures worldwide. A pest is any species, strain or biotype of plant, animal, or pathogenic agent injurious to plants or plant products. Worldwide, agricultural pest impacts are increased by higher degrees of interconnectedness. This is due to the increased risk that any particular pest problem anywhere in the world (as a system) will propagate across the entire system.


Plant defences against pests

Plants have developed strategies that they use in their own defence, be they thorns (modified stems) or spines (modified leaves), stings, a thick cuticle or waxy deposits, with the second line of defence being toxic or distasteful
secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the norm ...
s. Mechanical injury to the plant tissues allows the entry of pathogens and stimulates the plant to mobilise its chemical defences. The plant soon seals off the wound to reduce further damage. Plants sometimes take active steps to reduce herbivory. ''
Macaranga triloba ''Macaranga triloba'' is a species of plant in the family Euphorbiaceae. It is native to the tropical forests of southeastern Asia. It is a pioneer species, colonising recently cleared or burnt areas of the forest. Description A small, spread ...
'' for example has adapted its thin-walled stems to create ideal housing for an ant ''
Crematogaster ''Crematogaster'' is an ecologically diverse genus of ants found worldwide, which are characterised by a distinctive heart-shaped gaster (abdomen), which gives them one of their common names, the Saint Valentine ant. Members of this genus are a ...
'' spp., which, in turn, protects the plant from herbivores. In addition to providing housing, the plant also provides the ant with its exclusive food source in the form of
food bodies A Beltian body is a detachable tip found on the pinnules of some species of ''Acacia'' and closely related genera. Beltian bodies, named after Thomas Belt, are rich in lipids, sugars and proteins and often red in colour. They are believed to have ...
located on the leaf stipules. Similarly, several ''
Acacia ''Acacia'', commonly known as the wattles or acacias, is a large genus of shrubs and trees in the subfamily Mimosoideae of the pea family Fabaceae. Initially, it comprised a group of plant species native to Africa and Australasia. The genus nam ...
'' tree species have developed stout spines that are swollen at the base, forming a hollow structure that provides housing for ants which protect the plant. These ''Acacia'' trees also produce nectar in nectaries on their leaves as food for the ants.


Climate change

Pest ranges are heavily determined by
climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...
. The most common example for the longest time has been rainfall: Although
drought stress Drought tolerance is the ability to which a plant maintains its biomass production during arid or drought conditions. Some plants are naturally adapted to dry conditions'','' surviving with protection mechanisms such as desiccation tolerance, detox ...
weakens
crop disease resistance Plant disease resistance protects plants from pathogens in two ways: by pre-formed structures and chemicals, and by infection-induced responses of the immune system. Relative to a susceptible plant, disease resistance is the reduction of patho ...
, drought also retards contagion and infection; and some variability in precipitation is universal. More recently climate change has been rapidly altering ranges, mostly by pushing them towards the poles (both
North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' is ...
and South). From 1960-2013 ranges have shifted poleward by per year - albeit with significant differences between
taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
. (Especially in the case of viruses and
nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant- parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a bro ...
s which show the opposite trend, toward the equator. This may be due to their lack of
airborne dispersal Biological dispersal refers to both the movement of individuals (animals, plants, fungi, bacteria, etc.) from their birth site to their breeding site ('natal dispersal'), as well as the movement from one breeding site to another ('breeding dis ...
, so their trend conforms with the trend of
human-aided dispersal Biological dispersal refers to both the movement of individuals (animals, plants, fungi, bacteria, etc.) from their birth site to their breeding site ('natal dispersal'), as well as the movement from one breeding site to another ('breeding di ...
; or identification difficulties in the field.) In Europe, crop pests are expected to burgeon as the vertebrate predators which control them are expected to be suppressed by future climatic conditions.


Economic impact


In agriculture and horticulture

Together pests and diseases cause up to 40% yield losses every year. The animal groups of the greatest importance as agricultural pests are (in order of economic importance) insects, mites,
nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant- parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a bro ...
s and gastropod molluscs.Speiser B. (2002). "Chapter 219. Molluscicides". 506–508.
PDF
In: Pimentel D. (ed.) (2002). ''Encyclopedia of Pest Management''. .
Stange, L.A. (created September 2004, updated March 2006)

. Division of Plant Industry,
Florida Department of Agriculture and Consumer Services The Florida Department of Agriculture and Consumer Services (FDACS) is an executive department of the government of Florida. The Commissioner of Agriculture (directly elected by voters statewide for a four-year term, and a member of the Florid ...
. Accessed 27 August 2010.
Insects are responsible for two major forms of damage to crops. First, there is the direct injury they cause to the plants as they feed on the tissues; a reduction in leaf surface available for photosynthesis, distortion of growing shoots, a diminution of the plant's growth and vigour, and the wilting of shoots and branches caused by the insects' tunneling activities. Secondly there is the indirect damage, where the insects do little direct harm, but either transmit or allow entry of fungal, bacterial or viral infections. Although some insects are polyphagous, many are restricted to one specific crop, or group of crops. In many cases it is the larva that feeds on the plant, building up a nutritional store that will be used by the short-lived adult;
sawfly Sawflies are the insects of the suborder Symphyta within the order Hymenoptera, alongside ants, bees, and wasps. The common name comes from the saw-like appearance of the ovipositor, which the females use to cut into the plants where they lay ...
and lepidopteran larvae feed mainly on the aerial portions of plants while
beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
larvae tend to live underground, feeding on roots, or tunnel into the stem or under the bark. The true bugs,
Hemiptera Hemiptera (; ) is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from to aroun ...
, have piercing and sucking mouthparts and live by sucking sap from plants. These include
aphid Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...
s, whiteflies and
scale insect Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient grouping than the ...
s. Apart from weakening the plant, they encourage the growth of
sooty mould Sooty mold (also spelled sooty mould) is a collective term for different Ascomycete fungi, which includes many genera, commonly ''Cladosporium'' and ''Alternaria''. It grows on plants and their fruit, but also environmental objects, like fences, ...
on the honeydew the insects produce, which cuts out the light and reduces photosynthesis, stunting the plant's growth. They often transmit serious viral diseases between plants. The mites that cause most trouble in the field are the spider mites. These are less than in diameter, can be very numerous, and thrive in hot, dry conditions. They mostly live on the underside of leaves and puncture the plant cells to feed, with some species forming webbing. They occur on nearly all important food crops and ornamental plants, both outdoors and under glass, and include some of the most economically important pests. Another important group of mites is the gall mites which affect a wide range of plants, several mite species being major pests causing substantial economic damage to crops. They can feed on the roots or the aerial parts of plants and transmit viruses. Some examples are the big bud mite that transmits the reversion virus of
blackcurrant The blackcurrant (''Ribes nigrum''), also known as black currant or cassis, is a deciduous shrub in the family Grossulariaceae grown for its edible berries. It is native to temperate parts of central and northern Europe and northern Asia, whe ...
s, the
coconut mite ''Aceria guerreronis'', the coconut mite, is an eriophyid mite which infests coconut plantations. It is economically devastating, and can destroy up to 60% of coconut production. The immature nuts are infested and injured by mites feeding in the ...
which can devastate coconut production, and the cereal rust mite which transmits several grass and cereal viruses. Being exceedingly minute, many plant mites are spread by wind, although others use insects or other arthropods as a means to disperse. The nematodes (eelworms) that attack plants are minute, often too small to be seen with the naked eye, but their presence is often apparent in the galls or "knots" they form in plant tissues. Vast numbers of nematodes are found in soil and attack roots, but others affect stems, buds, leaves, flowers and fruits. High infestations cause stunting, deformation and retardation of plant growth, and the nematodes can transmit viral diseases from one plant to another. When its populations are high, the
potato cyst nematode Potato root nematodes or potato cyst nematodes (PCN) are 1-mm long roundworms belonging to the genus ''Globodera'', which comprises around 12 species. They live on the roots of plants of the family Solanaceae, such as potatoes and tomatoes. PCN c ...
can cause reductions of 80% in yield of susceptible potato varieties. The nematode eggs survive in the soil for many years, being stimulated to hatch by chemical cues produced by roots of susceptible plants.
Slug Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a smal ...
s and snails are terrestrial gastropod molluscs which typically chew leaves, stems, flowers, fruit and vegetable debris. Slugs and snails differ little from each other and both do considerable damage to plants. With novel crops being grown and with insect pests having been brought more under control by biological and other means, the damage done by molluscs becomes of greater significance. Terrestrial molluscs need moist environments; snails may be more noticeable because their shells provide protection from desiccation, while most slugs live in soil and only come out to feed at night. They devour seedlings, damage developing shoots and feed on salad crops and cabbages, and some species tunnel into potatoes and other tubers.


Weeds

A weed is a plant considered undesirable in a particular situation; the term has no botanical significance. Often, weeds are simply those native plants that are adapted to grow in disturbed ground, the disturbance caused by ploughing and cultivation favouring them over other species. Any plant is a weed if it appears in a location where it is unwanted;
Bermuda grass ''Cynodon dactylon'', commonly known as Bermuda grass, is a grass found worldwide. It is native to Europe, Africa, Australia and much of Asia. It has been introduced to the Americas. Although it is not native to Bermuda, it is an abundant invasiv ...
makes a good lawn plant under hot dry conditions but become a bad weed when it out-competes cultivated plants. A different group of weeds consists of those that are invasive, introduced, often unintentionally, to habitats to which they are not native but in which they thrive. Without their original competitors, herbivores, and diseases, they may increase and become a serious nuisance. One such plant is purple loosestrife, a native of Europe and Asia where it occurs in ditches, wet meadows and marshes; introduced into North America, it has no natural enemies to keep it in check and has taken over vast tracts of wetlands to the exclusion of native species.


In forestry

In forestry, pests may affect various parts of the tree, from its roots and trunk to the canopy far overhead. The accessibility of the part of the tree affected may make detection difficult, so that a pest problem may already be far advanced before it is first observed from the ground. The larch sawfly and
spruce budworm ''Choristoneura'' is a genus of moths in the family Tortricidae. Several species are serious pests of conifers, such as spruce and are known as spruce budworms. Species *'' Choristoneura adumbratanus'' (Walsingham, 1900) *'' Choristoneura afr ...
are two insect pests prevalent in Alaska and aerial surveys can show which sections of forest are being defoliated in any given year so that appropriate remedial action can be taken. Some pests may not be present on the tree all year round, either because of their life cycle or because they rotate between different host species at different times of the year. The larvae of wood-boring beetles may spend years excavating tunnels under the bark of trees, and only emerge into the open for brief periods as adults, to mate and disperse. The import and export of timber has inadvertently assisted some insect pests to establish themselves far from their country of origin. An insect may be of little importance in its native range, being kept under control by parasitoid wasps, predators, and the natural resistance of the host trees, but be a serious pest in a region into which it has been introduced. This is the case with the
emerald ash borer The emerald ash borer (''Agrilus planipennis''), also known by the acronym EAB, is a green buprestid or jewel beetle native to north-eastern Asia that feeds on ash species. Females lay eggs in bark crevices on ash trees, and larvae feed underne ...
, an insect native to north-eastern Asia, which, since its arrival in North America, has killed millions of ash trees.


In buildings

Animals able to live in the dry conditions found in buildings include many
arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chitin, o ...
s such as beetles, cockroaches, moths, and mites. Another group, including
termite Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattode ...
s,
woodworm A woodworm is the wood-eating larva of many species of beetle. It is also a generic description given to the infestation of a wooden item (normally part of a dwelling or the furniture in it) by these larvae. Types of woodworm Woodboring beetle ...
,
longhorn beetle The longhorn beetles (Cerambycidae), also known as long-horned or longicorns, are a large family of beetles, with over 35,000 species described. Most species are characterized by extremely long antennae, which are often as long as or longer than ...
s, and
wood ant The ''Formica rufa'' group is a subgeneric group within the genus ''Formica'', first proposed by William Morton Wheeler. This group contains the mound-building species of ''Formica'' commonly termed "wood ants" or "thatch-mound ants", which build ...
s cause structural damage to buildings and furniture. The natural habitat of these is the decaying parts of trees. The
deathwatch beetle The deathwatch beetle (''Xestobium rufovillosum'') is a species of woodboring beetle that sometimes infests the structural timbers of old buildings. The adult beetle is brown and measures on average long. Eggs are laid in dark crevices in old w ...
infests the structural timbers of old buildings, mostly attacking hardwood, especially oak. The initial attack usually follows the entry of water into a building and the subsequent decay of damp timber. Furniture beetles mainly attack the sapwood of both hard and soft wood, only attacking the heartwood when it is modified by fungal decay. The presence of the beetles only becomes apparent when the larvae gnaw their way out, leaving small circular holes in the timber. Carpet beetles and
clothes moth Clothes moth or clothing moth is the common name for several species of moth considered to be pests, whose larvae eat animal fibres (hairs), including clothing and other fabrics. These include: * ''Tineola bisselliella'', the common clothes mot ...
s cause non-structural damage to property such as clothing and carpets. It is the larvae that are destructive, feeding on wool, hair, fur, feathers and down. The moth larvae live where they feed, but the beetle larvae may hide behind skirting boards or in other similar locations between meals. They may be introduced to the home in any product containing animal fibres including upholstered furniture; the moths are feeble fliers but the carpet beetles may also enter houses through open windows. Furniture beetles, carpet beetles and clothes moths are also capable of creating great damage to museum exhibits, zoological and botanical collections, and other cultural heritage items. Constant vigilance is required to prevent an attack, and newly acquired items, and those that have been out on loan, may need quarantining before being added to the general collection. There are over four thousand species of cockroach worldwide, but only four species are commonly regarded as pests, having adapted to live permanently in buildings. Considered to be a sign of unsanitary conditions, they feed on almost anything, reproduce rapidly and are difficult to eradicate. They can passively transport pathogenic microbes on their body surfaces, particularly in environments such as hospitals, and are linked with allergic reactions in humans. Various insects attack dry food products, with
flour beetle Flour beetles are members of the darkling beetle genera '' Tribolium'' or '' Tenebrio''. They are pests of cereal silos and are widely used as laboratory animals, as they are easy to keep. The flour beetles consume wheat and other grains, are ad ...
s, the drugstore beetle, the sawtoothed grain beetle and the Indianmeal moth being found worldwide. The insects may be present in the warehouse or maybe introduced during shipping, in retail outlets, or in the home; they may enter packets through tiny cracks or may chew holes in the packaging. The longer a product is stored, the more likely it is to become contaminated, with the insects often originating from dry pet foods. Some mites, too, infest foodstuffs and other stored products. Each substance has its own specific mite, and they multiply with great rapidity. One of the most damaging is the
flour mite The flour mite, ''Acarus siro'', a pest of stored grains and animal feedstuffs, is one of many species of grain and flour mites. An older name for the species is ''Tyroglyphus farinae''. The flour mite, which is pale greyish white in colour wit ...
, which is found in grain and may become exceedingly abundant in poorly stored material. In time, predatory mites usually move in and control the flour mites.


Countermeasures


Pest control in agriculture and horticulture

The control of pests in crops is as old as civilisation. The earliest approach was mechanical, from ploughing to picking off insects by hand. Early methods included the use of sulphur compounds, before 2500 BC in Sumeria. In ancient China, insecticides derived from plants were in use by 1200 BC to treat seeds and to fumigate plants. Chinese agronomy recognised biological control by natural enemies of pests and the varying of planting time to reduce pests before the first century AD. The agricultural revolution in Europe saw the introduction of effective plant-based insecticides such as
pyrethrum ''Pyrethrum'' was a genus of several Old World plants now classified as ''Chrysanthemum'' or '' Tanacetum'' which are cultivated as ornamentals for their showy flower heads. Pyrethrum continues to be used as a common name for plants formerly incl ...
,
derris ''Derris'' is genus of leguminous plants found in Southeast Asia and the southwest Pacific islands, including New Guinea. The roots of '' D. elliptica'' contain rotenone, a strong insecticide and fish poison. Despite the secondary compounds foun ...
,
quassia ''Quassia'' ( or ) is a plant genus in the family Simaroubaceae. Its size is disputed; some botanists treat it as consisting of only one species, '' Quassia amara'' from tropical South America, while others treat it in a wide circumscription as ...
, and
tobacco Tobacco is the common name of several plants in the genus ''Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the chie ...
extract. The
phylloxera Grape phylloxera is an insect pest of commercial grapevines worldwide, originally native to eastern North America. Grape phylloxera (''Daktulosphaira vitifoliae'' (Fitch 1855) belong to the family Phylloxeridae, within the order Hemiptera, bugs ...
(a powdery mildew) damage to the wine industry in the 19th century resulted in the development of resistant varieties and grafting, and the accidental discovery of effective chemical pesticides,
Bordeaux mixture Bordeaux mixture (also called ''Bordo Mix'') is a mixture of copper(II) sulphate (CuSO4) and quicklime ( Ca O) used as a fungicide. It is used in vineyards, fruit-farms and gardens to prevent infestations of downy mildew, powdery mildew and othe ...
(lime and
copper sulphate Copper sulfate may refer to: * Copper(II) sulfate, CuSO4, a common compound used as a fungicide and herbicide * Copper(I) sulfate Copper(I) sulfate, also known as cuprous sulfate, is an inorganic compound with the chemical formula Cu2 SO4. I ...
) and Paris Green (an
arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but ...
compound), both very widely used. Biological control also became established as an effective measure in the second half of the 19th century, starting with the
vedalia beetle ''Novius cardinalis'' (common names vedalia beetle or cardinal ladybird) is a species of ladybird beetle native to Australia. It was formerly placed in the genus ''Rodolia'', but that genus was synonymized under the genus '' Novius'' in 2020.P ...
against
cottony cushion scale ''Icerya purchasi'' (common name: cottony cushion scale) is a scale insect that feeds on more than 80 families of woody plants, most notably on ''Citrus'' and ''Pittosporum''. Originally described in 1878 from specimens collected in New Zealand a ...
. All these methods have been refined and developed since their discovery.


Pest control in forestry

Forest pests inflict costly damage, but treating them is often unaffordable, given the relatively low value of forest products compared to agricultural crops. It is also generally impossible to eradicate forest pests, given the difficulty of examining entire trees, and the certainty that pesticides would damage many forest organisms other than the intended pests.
Forest integrated pest management Forest integrated pest management or Forest IPM is the practice of monitoring and managing pest and environmental information with pest control methods to prevent pest damage to forests and forest habitats by the most economical means. Forest IPM ...
therefore aims to use a combination of prevention, cultural control measures, and direct control (such as pesticide use). Cultural measures include choosing appropriate species, keeping competing vegetation under control, ensuring a suitable stocking density, and minimizing injury and stress to trees.


Pest control in buildings

Pest control in buildings can be approached in several ways, depending on the type of pest and the area affected. Methods include improving sanitation and garbage control, modifying the habitat, and using repellents, growth regulators, traps, baits and pesticides. For example, the pesticide
Boron Boron is a chemical element with the symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the ''boron group'' it has th ...
can be impregnated into the fibres of cellulose insulation to kill self-grooming insects such as ants and cockroaches. Clothes moths can be controlled with airtight containers for storage, periodic laundering of garments, trapping, freezing, heating and the use of chemicals. Traditional
mothball Mothballs are small balls of chemical pesticide and deodorant, sometimes used when storing clothing and other materials susceptible to damage from mold or moth larvae (especially clothes moths like ''Tineola bisselliella''). Composition Older ...
s deter adult moths with strong-smelling
naphthalene Naphthalene is an organic compound with formula . It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08  ppm by mass. As an aromati ...
; modern ones use volatile repellents such as
1,4-Dichlorobenzene 1,4-Dichlorobenzene (1,4-DCB, ''p''-DCB, or ''para''-dichlorobenzene, sometimes abbreviated as PDCB or para) is an organic compound with the formula C6H4Cl2. This colorless solid has a strong odor. The molecule consists of a benzene ring with ...
. Moth larvae can be killed with insecticides such as
permethrin Permethrin is a medication and an insecticide. As a medication, it is used to treat scabies and lice. It is applied to the skin as a cream or lotion. As an insecticide, it can be sprayed onto clothing or mosquito nets to kill the insects that ...
or pyrethroids. However, insecticides cannot safely be used in food storage areas; alternative treatments include freezing foods for four days at or baking for half an hour at to kill any insects present.


In mythology, religion, folklore, and culture

Pests have attracted human attention from the birth of civilisation. Plagues of locusts caused devastation in the ancient Middle East, and were recorded in tombs in Ancient Egypt from as early as 2470 BC, and in the Book of Exodus in the Bible, as taking place in Egypt around 1446 BC. Homer's '' Iliad'' mentions locusts taking to the wing to escape fire. Given the impact of agricultural pests on human lives, people have prayed for deliverance. For example, the 10th century Greek monk
Tryphon of Constantinople Tryphon ( gr, Τρύφων) (died 933) was a 10th-century Patriarch of Constantinople. He is venerated as a saint in the Eastern Orthodox Church. Life Tryphon was a monk in Constantinople. Patriarch Stephen II died on 15 July 928. Tryphon was r ...
is said to have prayed "Snails, earwigs and all other creatures, hurt not the vines, nor the land nor the fruit of the trees, nor the vegetables ... but depart into the wild mountains." The 11th-century Old English medical text ''
Lacnunga The ''Lacnunga'' ('Remedies') is a collection of miscellaneous Anglo-Saxon medical texts and prayers, written mainly in Old English and Latin. The title ''Lacnunga'', an Old English word meaning 'remedies', is not in the manuscript: it was given t ...
'' contained charms and spells to ward off or treat pests such as ''wid smeogan wyrme'', " penetrating worms", in this case requiring a charm to be sung, accompanied by covering the wound with spittle, pounded green centaury, and hot cow's urine. The 20th century "prayer against pests" including the words "By Your power may these injurious animals be driven off so that they will do no harm to any one and will leave our fields and meadows unharmed" was printed in the 1956 ''Rural Life Prayerbook''.


References


Further reading

* Hockings, F. D. 2014
''Pests, Diseases and Beneficials''
, CSIRO Publishing, Melbourne, *


External links

*
UF/IFAS Pest Alert Web site
-
arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chitin, o ...
s,
nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant- parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a bro ...
s and
plant diseases Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oom ...
affecting humans, livestock/pets, agricultural and ornamental plants. * {{Authority control Insects in culture