Pest control is the regulation or management of a species defined as a pest, a member of the animal kingdom that impacts adversely on human activities. The human response depends on the importance of the damage done, and will range from tolerance, through deterrence and management, to attempts to completely eradicate the pest. Pest control measures may be performed as part of an integrated pest management strategy.
In agriculture, pests are kept at bay by cultural, chemical and biological means. Ploughing and cultivation of the soil before sowing reduces the pest burden and there is a modern trend to limit the use of pesticides as far as possible. This can be achieved by monitoring the crop, only applying insecticides when necessary, and by growing varieties and crops which are resistant to pests. Where possible, biological means are used, encouraging the natural enemies of the pests and introducing suitable predators or parasites.
In homes and urban environments, the pests are the rodents, birds, insects and other organisms that share the habitat with humans, and that feed on and spoil possessions. Control of these pests is attempted through exclusion, repulsion, physical removal or chemical means. Alternatively, various methods of biological control can be used including sterilisation programmes.
Pest control is at least as old as agriculture, as there has always been a need to keep crops free from pests. As long ago as 3000 BC in Egypt, cats were used to control pests of grain stores such as rodents. Ferrets were domesticated by 500 AD in Europe for use as mousers. Mongooses were introduced into homes to control rodents and snakes, probably by the ancient Egyptians.
The conventional approach was probably the first to be employed, since it is comparatively easy to destroy weeds by burning them or ploughing them under, and to kill larger competing herbivores. Techniques such as crop rotation, companion planting (also known as intercropping or mixed cropping), and the selective breeding of pest-resistant cultivars have a long history.
Chemical pesticides were first used around 2500 BC, when the Sumerians used sulphur compounds as insecticides. Modern pest control was stimulated by the spread across the United States of the Colorado potato beetle. After much discussion, arsenical compounds were used to control the beetle and the predicted poisoning of the human population did not occur. This led the way to a widespread acceptance of insecticides across the continent. With the industrialisation and mechanization of agriculture in the 18th and 19th centuries, and the introduction of the insecticides pyrethrum and derris, chemical pest control became widespread. In the 20th century, the discovery of several synthetic insecticides, such as DDT, and herbicides boosted this development.
Biological control is first recorded around 300 AD in China, when colonies of weaver ants, Oecophylla smaragdina, were intentionally placed in citrus plantations to control beetles and caterpillars. Also in China, ducks were used in paddy fields to consume pests, as illustrated in ancient cave art. In 1762, an Indian mynah was brought to Mauritius to control locusts, and about the same time, citrus trees in Burma were connected by bamboos to allow ants to pass between them and help control caterpillars. In the 1880s, ladybirds were used in citrus plantations in California to control scale insects, and other biological control experiments followed. The introduction of DDT, a cheap and effective compound, put an effective stop to biological control experiments. By the 1960s, problems of resistance to chemicals and damage to the environment began to emerge, and biological control had a renaissance. Chemical pest control is still the predominant type of pest control today, although a renewed interest in traditional and biological pest control developed towards the end of the 20th century and continues to this day.
In agriculture, horticulture and forestryEdit
Biological pest controlEdit
Biological pest control is a method of controlling pests such as insects and mites by using other organisms. It relies on predation, parasitism, herbivory or other natural mechanisms, but typically also involves an active human management role. Classical biological control involves the introduction of natural enemies of the pest that are bred in the laboratory and released into the environment. An alternative approach is to augment the natural enemies that occur in a particular area by releasing more, either in small, repeated batches, or in a single large-scale release. Ideally, the released organism will breed and survive, and provide long-term control. Biological control can be an important component of an integrated pest management programme.
Mechanical pest control is the use of hands-on techniques as well as simple equipment and devices, that provides a protective barrier between plants and insects. This is referred to as tillage and is one of the oldest methods of weed control as well as being useful for pest control; wireworms, the larvae of the common click beetle, are very destructive pests of newly ploughed grassland, and repeated cultivation exposes them to the birds and other predators that feed on them.
Crop rotation can help to control pests by depriving them of their host plants. It is a major tactic in the control of corn rootworm, and has reduced early season incidence of Colorado potato beetle by as much as 95%.
A trap crop is a crop of a plant that attracts pests, diverting them from nearby crops. Pests aggregated on the trap crop can be more easily controlled using pesticides or other methods. However, trap-cropping, on its own, has often failed to cost effectively reduce pest densities on large commercial scales, without the use of pesticides, possibly due to the pests' ability to disperse back into the main field.
Pesticides are applied to crops by agricultural aircraft, tractor-mounted crop sprayers or as seed dressings to control pests. However, successful control by pesticides is not easy; the right formulation must be chosen, the timing is often critical, the method of application is important, adequate coverage and retention on the crop are necessary. The killing of natural enemies of the target pest should be minimised. This is particularly important in countries where there are natural reservoirs of pests and their enemies in the countryside surrounding plantation crops, and these co-exist in a delicate balance. Often in less-developed countries, the crops are well adapted to the local situation and no pesticides are needed. Where progressive farmers are using fertilisers to grow improved crop varieties, these are often more susceptible to pest damage, but the indiscriminate application of pesticides may be detrimental in the longer term.
The efficacy of chemical pesticides tends to diminish over time. This is because any organism that manages to survive the initial application will pass on its genes to its offspring and a resistant strain will be developed. In this way, some of the most serious pests have developed resistance and are no longer killed by pesticides that used to kill their ancestors. This necessitates higher concentrations of chemical, more frequent applications and a movement to more expensive formulations.
Pesticides are formulated to kill pests, but many have detrimental effects on non-target species; of particular concern is the damage done to honey-bees, solitary bees and other pollinating insects and in this regard, the time of day when the spray is applied can be important. The widely used neonicotinoids have been banned on flowering crops in some countries because of their effects on bees. Some pesticides may cause cancer and other health problems in humans, as well as being harmful to wildlife. There can be acute effects immediately after exposure or chronic effects after continuous low-level, or occasional exposure. Maximum residue limits for pesticides in foodstuffs and animal feed are set by many nations.
Forest pests present a significant problem because it is not easy to access the canopy and monitor pest populations. In addition, forestry pests such as bark beetles, kept under control by natural enemies in their native range, may be transported large distances in cut timber to places where they have no natural predators, enabling them to cause extensive economic damage. Pheromone traps have been used to monitor pest populations in the canopy. These release volatile chemicals that attract males. Pheromone traps can detect the arrival of pests or alert foresters to outbreaks. For example, the spruce budworm, a destructive pest of spruce and balsam fir, has been monitored using pheromone traps in Canadian forests for several decades. In some regions, such as New Brunswick, areas of forest are sprayed with pesticide to control the budworm population and prevent the damage caused during outbreaks.
In homes and citiesEdit
Many unwelcome animals visit or make their home in residential buildings, industrial sites and urban areas. Some contaminate foodstuffs, damage structural timbers, chew through fabrics or infest stored dry goods. Some inflict great economic loss, others carry diseases or cause fire hazards, and some are just a nuisance. Control of these pests has been attempted by improving sanitation and garbage control, modifying the habitat, and using repellents, growth regulators, traps, baits and pesticides.
Physical pest controlEdit
Physical pest control involves trapping or killing pests such as insects and rodents. Historically, local people or paid rat-catchers caught and killed rodents using dogs and traps. On a domestic scale, sticky flypapers are used to trap flies. In larger buildings, insects may be trapped using such means as pheromones, synthetic volatile chemicals or ultraviolet light to attract the insects; some have a sticky base or an electrically charged grid to kill them. Glueboards are sometimes used for monitoring cockroaches and to catch rodents. Rodents can be killed by suitably baited spring traps and can be caught in cage traps for relocation. Talcum powder or "tracking powder" can be used to establish routes used by rodents inside buildings and acoustic devices can be used for detecting beetles in structural timbers.
Poisoned bait is a common method for controlling rats, mice, birds, slugs, snails, ants, cockroaches and other pests. The basic granules, or other formulation, contains a food attractant for the target species and a suitable poison. For ants, a slow-acting toxin is needed so that the workers have time to carry the substance back to the colony, and for flies, a quick-acting substance to prevent further egg-laying and nuisance. Baits for slugs and snails often contain the molluscide metaldehyde, dangerous to children and household pets.
Warfarin has traditionally been used to kill rodents, but many populations have developed resistance to this anticoagulant, and difenacoum is often substituted. These are cumulative poisons, requiring bait stations to be topped up regularly. Poisoned meat has been used for centuries to kill animals such as wolves and birds of prey. Poisoned carcasses however kill a wide range of carrion feeders, not only the targeted species. Raptors in Israel were nearly wiped out following a period of intense poisoning of rats and other crop pests.
Fumigation is the treatment of a structure to kill pests such as wood-boring beetles by sealing it or surrounding it with an airtight cover such as a tent, and fogging with liquid insecticide for an extended period, typically of 24–72 hours. This is costly and inconvenient as the structure cannot be used during the treatment, but it targets all life stages of pests.
An alternative, space treatment, is fogging or misting to disperse a liquid insecticide in the atmosphere within a building without evacuation or airtight sealing, allowing most work within the building to continue, at the cost of reduced penetration. Contact insecticides are generally used to minimise long lasting residual effects.
Populations of pest insects can sometimes be dramatically reduced by the release of sterile individuals. This involves the mass rearing of a pest, sterilising it by means of X-rays or some other means, and releasing it into a wild population. It is particularly useful where a female only mates once and where the insect does not disperse widely. This technique has been successfully used against the New World screw-worm fly, some species of tsetse fly, tropical fruit flies, the pink bollworm and the codling moth, among others.
Laboratory studies conducted with U-5897 (3-chloro-1,2-propanediol) were attempted in the early 1970s for rat control, although these proved unsuccessful. In 2013, New York City tested sterilization traps, demonstrating a 43% reduction in rat populations. The product ContraPest was approved for the sterilization of rodents by the United States Environmental Protection Agency in August 2016.
Methods for specific pestsEdit
Natural rodent controlEdit
Several wildlife rehabilitation organizations encourage natural form of rodent control through exclusion and predator support and preventing secondary poisoning altogether. The United States Environmental Protection Agency notes in its Proposed Risk Mitigation Decision for Nine Rodenticides that "without habitat modification to make areas less attractive to commensal rodents, even eradication will not prevent new populations from recolonizing the habitat." The United States Environmental Protection Agency has prescribed guidelines for natural rodent control and for safe trapping in residential areas with subsequent release to the wild. People sometimes attempt to limit rodent damage using repellents. Balsam fir oil from the tree Abies balsamea is an EPA approved non-toxic rodent repellent. Acacia polyacantha subsp. campylacantha root emits chemical compounds that repel animals including rats.
Insect pests including the Mediterranean flour moth, the Indian mealmoth, the cigarette beetle, the drugstore beetle, the confused flour beetle, the red flour beetle, the merchant grain beetle, the sawtoothed grain beetle, the wheat weevil, the maize weevil and the rice weevil infest stored dry foods such as flour, cereals and pasta.
In the home, foodstuffs found to be infested are usually discarded, and storing such products in sealed containers should prevent the problem from reoccurring. The eggs of these insects are likely to go unnoticed, with the larvae being the destructive life stage, and the adult the most noticeable stage. Since pesticides are not safe to use near food, alternative treatments such as freezing for four days at 0 °F (−18 °C) or baking for half an hour at 130 °F (54 °C) should kill any insects present.
The larvae of clothes moths (mainly Tineola bisselliella and Tinea pellionella) feed on fabrics and carpets, particularly those that are stored or soiled. The adult females lay batches of eggs on natural fibres, including wool, silk and fur, as well as cotton and linen in blends. The developing larvae spin protective webbing and chew into the fabric, creating holes and specks of excrement. Damage is often concentrated in concealed locations, under collars and near seams of clothing, in folds and crevices in upholstery and round the edges of carpets as well as under furniture. Methods of control include using airtight containers for storage, periodic laundering of garments, trapping, freezing, heating and the use of chemicals; mothballs contain volatile insect repellents such as 1,4-Dichlorobenzene which deter adults, but to kill the larvae, permethrin, pyrethroids or other insecticides may need to be used.
Carpet beetles are members of the family Dermestidae, and while the adult beetles feed on nectar and pollen, the larvae are destructive pests in homes, warehouses and museums. They feed on animal products including wool, silk, leather, fur, the bristles of hair brushes, pet hair, feathers and museum specimens. They tend to infest hidden locations and may feed on larger areas of fabrics than do clothes moths, leaving behind specks of excrement and brown, hollow, bristly-looking cast skins. Management of infestations is difficult and is based on exclusion and sanitation where possible, resorting to pesticides when necessary. The beetles can fly in from outdoors and the larvae can survive on lint fragments, dust and inside the bags of vacuum cleaners. In warehouses and museums, sticky traps baited with suitable pheromones can be used to identify problems, and heating, freezing, spraying the surface with insecticide and fumigation will kill the insects when suitably applied. Susceptible items can be protected from attack by keeping them in clean airtight containers.
Books are sometimes attacked by cockroaches, silverfish, book mites, booklice, and various beetles which feed on the covers, paper, bindings and glue. They leave behind physical damage in the form of tiny holes as well as staining from their faeces. Book pests include the larder beetle, and the larvae of the black carpet beetle and the drugstore beetle which attack leather-bound books, while the common clothes moth and the brown house moth attack cloth bindings. These attacks are largely a problem with historic books, because modern bookbinding materials are less susceptible to this type of damage.
Evidence of attack may be found in the form of tiny piles of book-dust and specks of frass. Damage may be concentrated in the spine, the projecting edges of pages and the cover. Prevention of attack relies on keeping books in cool, clean, dry positions with low humidity, and occasional inspections should be made. Treatment can be by freezing for lengthy periods, but some insect eggs are very resistant and can survive for long periods at low temperatures.
Various beetles in the Bostrichoidea superfamily attack the dry, seasoned wood used as structural timber in houses and to make furniture. In most cases, it is the larvae that do the damage; these are invisible from the outside of the timber, but are chewing away at the wood in the interior of the item. Examples of these are the powderpost beetles, which attack the sapwood of hardwoods, and the furniture beetles, which attacks softwoods, including plywood. The damage has already been done by the time the adult beetles bore their way out, leaving neat round holes behind them. The first that a householder knows about the beetle damage is often when a chair leg breaks off or a piece of structural timber caves in. Prevention is through chemical treatment of the timber prior to its use in construction or in furniture manufacture.
Termites with colonies in close proximity to houses can extend their galleries underground and make mud tubes to enter homes. The insects keep out of sight and chew their way through structural and decorative timbers, leaving the surface layers intact, as well as through cardboard, plastic and insulation materials. Their presence may become apparent when winged insects appear and swarm in the home in spring. Control and extermination is a professional job involving trying to exclude the insects from the building and trying to kill those already present. Soil-applied liquid termiticides provide a chemical barrier that prevents termites from entering buildings, and lethal baits can be used; these are eaten by foraging insects, and carried back to the nest and shared with other members of the colony, which goes into slow decline.
Birds are a significant hazard to aircraft, but it is difficult to keep them away from airfields. Several methods have been explored. Stunning birds by feeding them a bait containing stupefying substances has been tried, and it may be possible to reduce their numbers on airfields by reducing the number of earthworms and other invertebrates by soil treatment. Leaving the grass long on airfields rather than mowing it is also a deterrent to birds. Sonic nets are being trialled; these produce sounds that birds find distracting and seem effective at keeping birds away from affected areas.
- Taylor, D., The Complete Contented Cat: Your Ultimate Guide to Feline Fulfilment, David & Charles, 2011, p.9.
- Beadle, M., Cat, Simon and Schuster, 1979, pp. 93–96.
- Sherman, D.M., Tending Animals in the Global Village: A Guide to International Veterinary Medicine, John Wiley & Sons, 2007, p. 45.
- Chrispeels, Maarten J.; Sadava, David E. (1994). Plants, Genes, and Agriculture. Jones and Bartlett Publishers. p. 452. ISBN 978-0-86720-871-9.
- "The History of Integrated Pest Management". Cornell University. Retrieved 27 August 2017. which cites Orlob, G.B. (1973). "Ancient and medieval plant pathology". Pflanzenschutz-Nachrichten. 26: 65–294.
- van Emden, Helmut F. (1991). Pest Control. Cambridge University Press. pp. 1–4. ISBN 978-0-521-42788-3.
- van Emden, H.F.; Service, M.W. (2004). Pest and Vector Control. Cambridge University Press. p. 147. ISBN 978-0-521-01083-2.
- Flint, Maria Louise; Dreistadt, Steve H. (1998). Clark, Jack K., ed. Natural Enemies Handbook: The Illustrated Guide to Biological Pest Control. University of California Press. ISBN 978-0-520-21801-7. Archived from the original on 15 May 2016.
- "Augmentation: The Periodic Release of Natural Enemies". University of Wisconsin. Archived from the original on 17 March 2016. Retrieved 27 August 2017.
- "Bacillus thuringienis Factsheet". Colorado State University. Retrieved 2010-06-02.
- "Agriotes sputator L. - Common Click Beetle (Wireworm)". Interactive Agricultural Ecological Atlas of Russia and Neighboring Countries. Retrieved 27 August 2017.
- Wright, R. j (1984). "Evaluation of crop rotation for control of Colorado potato beetle (Coleoptera: Chrysomelidae) in commercial potato fields on Long Island". Journal of Economic Entomology. 77: 1254–1259.
- Shelton, A. M.; Badenes-Perez, F. R. (2005-12-06). "Concepts and applications of trap cropping in pest management". Annual Review of Entomology. 51 (1): 285–308. doi:10.1146/annurev.ento.51.110104.150959.
- Holden, Matthew H.; Ellner, Stephen P.; Lee, Doo-Hyung; Nyrop, Jan P.; Sanderson, John P. (2012-06-01). "Designing an effective trap cropping strategy: the effects of attraction, retention and plant spatial distribution". Journal of Applied Ecology. 49 (3): 715–722. doi:10.1111/j.1365-2664.2012.02137.x.
- Hill, Dennis S. (1983). Agricultural Insect Pests of the Tropics and Their Control. CUP Archive. pp. 4–5. ISBN 978-0-521-24638-5.
- Georghiou, G.P. (2012). Pest Resistance to Pesticides. Springer Science & Business Media. pp. 1–3. ISBN 978-1-4684-4466-7.
- Carrington, Damian (29 June 2017). "Pesticides damage survival of bee colonies, landmark study shows". The Guardian. Retrieved 27 August 2017.
- "Pesticides". National Institute of Health Sciences. National Institute of Environmental Health. Retrieved 5 April 2013.
- "Toxicity of Pesticides". Pesticide Safety Education Program. 2012. Retrieved 27 August 2017.
- "Maximum Residue Levels". Plants. European Commission. Retrieved 27 August 2017.
- Lieutier, François; Day, Keith R.; Battisti, Andrea; Grégoire, Jean-Claude; Evans, Hugh F. (2007). Bark and Wood Boring Insects in Living Trees in Europe, a Synthesis. Springer. p. 39. ISBN 978-1-4020-2241-8.
- Humme, Hans E.; Miller, Thomas A. (2012). Techniques in Pheromone Research. Springer. p. 432. ISBN 978-1-4612-5220-7.
- Macdonald, D. R. (1968). "Management of Spruce Budworm Populations". The Forestry Chronicle. 44 (3): 33–36. doi:10.5558/tfc44033-3.
- Pat O'Connor-Marer (2006). Residential, Industrial, and Institutional Pest Control. UCANR Publications. pp. 2–17. ISBN 978-1-879906-70-9.
- "ESDAW-EU". Animal Policy In The EU. European Union. Retrieved 30 August 2016.
- Pat O'connor-marer (2006). Residential, Industrial, and Institutional Pest Control. UCANR Publications. ISBN 978-1-879906-70-9.
- Flint, M.L.; Wilen, C.A. "Snails and slugs". Pests in Gardens and Landscapes. UC IPM. Retrieved 28 August 2017.
- "Dicoumarol". ScienceDirect. Elsevier B.V. Retrieved 28 August 2017.
- Anderson, Emma (9 June 2015). "Farmer poisoned 24 animals in bid to kill wolf". The Local. Retrieved 29 August 2017.
- Barkham, Patrick (2 October 2014). "Gamekeeper found guilty of poisoning 10 buzzards and a sparrowhawk". The Guardian. Retrieved 29 August 2017.
- Newton, Ian (2010). Population Ecology of Raptors. Bloomsbury Publishing. p. 262. ISBN 978-1-4081-3854-0.
- Fred Baur. Insect Management for Food Storage and Processing. American Association of Cereal Chemists. ISBN 0-913250-38-4.
- Thacker, J.R.M. (2002). An Introduction to Arthropod Pest Control. Cambridge University Press. p. 193. ISBN 978-0-521-56787-9.
- Dyck, V.A.; Hendrichs, J.; Robinson, A.S. (2006). Sterile Insect Technique: Principles and Practice in Area-Wide Integrated Pest Management. Springer Science & Business Media. p. 4. ISBN 978-1-4020-4051-1.
- Bowerman, Alan M.; Brooks, Joe E. (1971). "Evaluation of U-5897 as a male chemosterilant for rat control". Journal of Wildlife Management. 35 (4): 618–624. doi:10.2307/3799765. JSTOR 3799765.
- Tracy Swartz (22 Dec 2014). "CTA to put rats on birth control". Chicago Tribune. Retrieved 10 January 2015.
- "ContraPest Rodent Control Product Wins EPA Approval". Pest Control Technology, GIA Media. 12 August 2016. Retrieved 11 November 2016.
- "Help WildCare Pursue Stricter Rodenticide Controls in California". wildcarebayarea.org/. Wild Care. Retrieved 28 February 2014.
- "Safer Rodenticide Products". epa.gov. USA Environment Protection Agency. March 2013. Retrieved 23 February 2014.
- "Pest Control and Pesticide Safety for Consumers". Retrieved 23 July 2017.
- Craft, Stephanie. "5 Reasons Why a DIY Approach to Pest Control Fails". Retrieved 23 July 2017.
- Balsam fir oil (129035) Fact Sheet | Pesticides | US EPA
- World AgroForestry Centre
- "Mediterranean Flour Moth (Department of Entomology)". Department of Entomology (Penn State University). Retrieved 14 November 2017.
- Jacobs, Steve (1 January 2013). "Cereal and Pantry Pests". Penn State: Department of Entomology. Retrieved 30 August 2017.
- Hahn, Jeffrey; Jesse, Laura; Pellitteri, Phil. "Insect pests of stored foods". University of Minnesota Extension. Retrieved 30 August 2017.
- Choe, D.-H. (1 March 2013). "Clothes moths". Agriculture and Natural Resources, University of California. Retrieved 1 September 2017.
- Choe, D.-H. (1 December 2012). "Carpet beetles". Agriculture and Natural Resources, University of California. Retrieved 1 September 2017.
- "Conservation: Approaches to Insect Problems in Paper and Books". Harry Ransom Center. Retrieved 2 September 2017.
- Greenfield, Jane (2014). The Care of Fine Books. Skyhorse Publishing. p. 67. ISBN 978-1-62914-048-3.
- Murray, Stuart (2009). The Library: An Illustrated History. Skyhorse Publishing. p. 198.
- Gerozisis, John; Hadlington, Phillip; Staunton, Ion (2008). Urban Pest Management in Australia. UNSW Press. pp. 131–135. ISBN 978-0-86840-894-1.
- "Termite Control: Answers for Homeowners". Termite control. University of Kentucky: Entomology. 1 March 2004. Retrieved 3 September 2017.
- Murton, R.K.; Wright, E.N. (2013). The Problems of Birds as Pests: Proceedings of a Symposium Held at the Royal Geographical Society, London, on 28 and 29 September 1967. Elsevier. pp. 100, 184. ISBN 978-1-4832-6836-1.
- Reed Business Information (29 May 1986). New Scientist. Reed Business Information. pp. 44–47. ISSN 0262-4079.
- Swaddle, John P.; Moseley, Dana L.; Hinders, Mark K.; Peyton Smith, E. (6 May 2016). "Sonic net could save birds and aircraft, study suggests". University of Exeter. Retrieved 28 August 2017.