Editing Pest control (section)

===Control methods===
====Biological pest control====
{{main|Biological pest control}}
[[File:Cotesia9061.8.15.07.c.jpg|thumb|[[Biological pest control]]: [[parasitoid wasp]] (''[[Cotesia congregata]])'' adult with pupal cocoons on its host, a tobacco hornworm ''[[Manduca sexta]]'' (green background)]]

Biological pest control is a method of controlling pests such as [[insect]]s and [[mite]]s by [[bioeffector|using other organisms]].<ref>{{cite book|author=Flint, Maria Louise |author2=Dreistadt, Steve H. |editor=Clark, Jack K. |title=Natural Enemies Handbook: The Illustrated Guide to Biological Pest Control |publisher=University of California Press |year=1998 |isbn=978-0-520-21801-7 |url=https://books.google.com/books?id=FBJvpMqcV9UC |url-status=live |archive-url=https://web.archive.org/web/20160515072525/https://books.google.com/books?id=FBJvpMqcV9UC&printsec=frontcover |archive-date=15 May 2016 }}</ref> It relies on [[predation]], [[parasitism]], [[Herbivore|herbivory]], [[Parasitoid|parasitody]] 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.<ref>{{cite web|title=Augmentation: The Periodic Release of Natural Enemies |url=http://www.entomology.wisc.edu/mbcn/fea104.html |publisher=University of Wisconsin |access-date=27 August 2017 |url-status=live |archive-url=https://web.archive.org/web/20160317104655/http://www.entomology.wisc.edu/mbcn/fea104.html |archive-date=17 March 2016 }}</ref> Biological control can be an important component of an [[integrated pest management]] programme.

For example: mosquitoes are often controlled by putting ''Bt [[Bacillus thuringiensis]]'' ssp. ''israelensis'', a bacterium that infects and kills mosquito larvae, in local water sources.<ref>{{cite web|url=http://www.ext.colostate.edu/pubs/insect/05556.html|title=''Bacillus thuringienis'' Factsheet|publisher=[[Colorado State University]]|access-date=2 June 2010}}</ref> <!--needs rewrite from that article-->

====Cultural control====
[[File:Following the plough 3 - geograph.org.uk - 1019422.jpg|thumb|Cultivation by [[ploughing]] exposes insect pests to predators such as [[black-headed gull]]s.]]
[[File: Choristoneura fumiferana.jpg|thumb|[[Choristoneura fumiferana|Spruce budworm]] (adult and pupa shown), a serious pest of forests, can be monitored using [[pheromone trap]]s.]]
{{main|Mechanical pest control|Insect trap|Crop rotation}}
[[Mechanical pest control]] is the use of hands-on techniques as well as simple equipment and devices, that provides a [[Termite barrier|protective barrier]] between [[plant]]s and [[insect]]s. 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 [[Agriotes sputator|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.<ref name=AgroAtlas>{{cite web |url=http://www.agroatlas.ru/en/content/pests/Agriotes_sputator/ |title=''Agriotes sputator'' L. - Common Click Beetle (Wireworm)|work=Interactive Agricultural Ecological Atlas of Russia and Neighboring Countries |access-date=27 August 2017}}</ref>

[[Crop rotation]] can help to control pests by depriving them of their [[Host (biology)|host plants]]. It is a major tactic in the control of [[Diabrotica|corn rootworm]], and has reduced early season incidence of [[Colorado potato beetle]] by as much as 95%.<ref>{{cite journal |author1=Wright, R. j |date=1984 |title=Evaluation of crop rotation for control of Colorado potato beetle (Coleoptera: Chrysomelidae) in commercial potato fields on Long Island |journal=Journal of Economic Entomology |volume=77 |issue=5 |pages=1254–1259 |url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1103&context=entomologyfacpub |doi=10.1093/jee/77.5.1254}}</ref>

====Trap cropping====
{{main|Trap crop}}
A [[trap crop]] is a crop of a plant that attracts pests, diverting them from nearby crops.<ref name=":02">{{Cite journal |last1=Shelton |first1=A. M. |last2=Badenes-Perez|first2=F. R. |date=6 December 2005 |title=Concepts and applications of trap cropping in pest management |journal=Annual Review of Entomology |volume=51 |issue=1 |pages=285–308 |doi=10.1146/annurev.ento.51.110104.150959|pmid=16332213 }}</ref> Pests aggregated on the trap crop can be more easily controlled using pesticides or other methods.<ref name=":1">{{Cite journal |last1=Holden |first1=Matthew H. |last2=Ellner |first2=Stephen P. |last3=Lee |first3=Doo-Hyung |last4=Nyrop |first4=Jan P. |last5=Sanderson |first5=John P. |date=1 June 2012 |title=Designing an effective trap cropping strategy: the effects of attraction, retention and plant spatial distribution |journal=Journal of Applied Ecology |volume=49 |issue=3 |pages=715–722 |doi=10.1111/j.1365-2664.2012.02137.x|doi-access=free |bibcode=2012JApEc..49..715H }}</ref> 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.<ref name=":1" />

====Pesticides====
{{main|Pesticide}}
[[File:Insecticide pine logs ips sexdentatus.jpg|thumb|Spraying [[pine]] logs with [[insecticide]] against ''[[Ips sexdentatus]]'', a pine engraver beetle]]
<!--aircraft spraying crops: image in lead section-->

[[Pesticide]]s are substances applied to crops to control pests, they include [[herbicide]]s to kill weeds, [[fungicide]]s to kill fungi and [[insecticide]]s to kill insects. They can be applied as sprays by hand, tractors, or aircraft or as [[seed dressing]]s. To be effective, the correct substance must be applied at the correct time and the method of application is important to ensure adequate coverage and retention on the crop. The killing of natural enemies of the target pest should be minimized. 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 fertilizers 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.<ref name=Hill>{{cite book |author=Hill, Dennis S.|title=Agricultural Insect Pests of the Tropics and Their Control |url=https://books.google.com/books?id=Ywc5AAAAIAAJ&pg=PA4 |year=1983 |publisher=CUP Archive |isbn=978-0-521-24638-5 |pages=4–5}}</ref>{{unreliable-inline|date=November 2023}}{{failed verification|date=November 2023}}
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 [[Pesticide resistance|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.<ref name=Georghiou>{{cite book|author=Georghiou, G.P.|title=Pest Resistance to Pesticides |url=https://books.google.com/books?id=SavaBwAAQBAJ&pg=PA1 |year=2012 |publisher=Springer Science & Business Media|isbn=978-1-4684-4466-7 |pages=1–3}}</ref>

Pesticides are intended to kill pests, but many have detrimental effects on non-target species; of particular concern is the [[Pesticide toxicity to bees|damage]] done to [[honey-bee]]s, solitary bees and other [[pollinating insect]]s and in this regard, the time of day when the spray is applied can be important.<ref name=Carrington/> The widely used [[neonicotinoid]]s have been banned on flowering crops in some countries because of their effects on bees.<ref name=Carrington>{{cite news |title=Pesticides damage survival of bee colonies, landmark study shows |author=Carrington, Damian |url=https://www.theguardian.com/environment/2017/jun/29/pesticides-damage-survival-of-bee-colonies-landmark-study-shows |newspaper=The Guardian |date=29 June 2017 |access-date=27 August 2017}}</ref> Some pesticides may cause [[cancer]] and other health problems in humans, as well as being harmful to wildlife.<ref name="National Institute of Environmental Health Sciences">{{cite web|title=Pesticides|url=http://www.niehs.nih.gov/health/topics/agents/pesticides/|work=National Institute of Health Sciences|publisher=National Institute of Environmental Health|access-date=5 April 2013}}</ref> There can be acute effects immediately after exposure or chronic effects after continuous low-level, or occasional exposure.<ref>{{cite web |url=http://psep.cce.cornell.edu/Tutorials/core-tutorial/module04/index.aspx |title=Toxicity of Pesticides |year=2012 |work=Pesticide Safety Education Program |access-date=27 August 2017 |archive-date=21 July 2021 |archive-url=https://web.archive.org/web/20210721082302/http://psep.cce.cornell.edu/Tutorials/core-tutorial/module04/index.aspx |url-status=dead }}</ref> [[Maximum residue limit]]s for pesticides in foodstuffs and animal feed are set by many nations.<ref>{{cite web |url=https://ec.europa.eu/food/plant/pesticides/max_residue_levels_en |title=Maximum Residue Levels |work=Plants |publisher=European Commission |access-date=27 August 2017}}</ref>

====Genetics====
{{seealso|Plant defense against herbivory}}
{{seealso|Plant disease resistance}}
Using crops with [[inheritable]] resistance to pests is referred to as host-plant resistance and reduces the need for pesticide use. These crops can harm or even kill pests, repel feeding, prevent colonization, or tolerate the presence of a pest without significantly impacting yield.<ref>{{cite web |title=Host Plant Resistance |url=https://vegento.russell.wisc.edu/ipm/host-plant-resistance/ |website=vegento.russell.wisc.edu |publisher=University of Wisconsin |access-date=13 November 2023}}</ref><ref>{{cite book |last1=Smith |first1=Charles Michael |title=Plant resistance to arthropods: molecular and conventional approaches |date=2005 |publisher=Springer |location=Dordrecht, the Netherlands |isbn=978-1-4020-3702-3}}</ref><ref>{{cite book |last1=Pedigo |first1=Larry P. |last2=Rice |first2=Marlin E. |last3=Krell |first3=Rayda K. |title=Entomology and Pest Management: Seventh Edition |date=15 March 2021 |publisher=Waveland Press |isbn=978-1-4786-4713-3 |url=https://books.google.com/books?id=gBMoEAAAQBAJ |language=en}}</ref> Resistance can also occur through [[genetic engineering]] to have traits with resistance to insects, such as with [[Bt corn]], or papaya resistance to ringspot virus.<ref>{{cite web |last1=Stearns |first1=Stacey |title=Genetic Engineering and Plant Protection {{!}} Science of GMOs |url=https://gmo.uconn.edu/topics/genetic-engineering-and-plant-protection/ |website=Genetic Engineering and Plant Protection |publisher=University of Connecticut |access-date=13 November 2023 |date=3 October 2017}}</ref> When farmers are purchasing seed, variety information often includes resistance to selected pests in addition to other traits.<ref>{{cite web |title=Disease Resistant Vegetable Varieties {{!}} Cornell Vegetables |url=https://www.vegetables.cornell.edu/pest-management/disease-factsheets/disease-resistant-vegetable-varieties/ |website=www.vegetables.cornell.edu |publisher=Cornell University |access-date=13 November 2023}}</ref>

====Hunting====
[[File:Passenger pigeon shoot.jpg|thumb|A contemporary wood engraving of varmint hunters shooting [[passenger pigeon]]s, a varmint species that was known to damage crops. [[Overhunting]] resulted in complete extinction of the species.]]
{{main|Varmint hunting}}
Pest control can also be achieved via [[culling]] the pest animals — generally small- to medium-sized [[wildlife|wild]] or [[feral]] mammals or birds that inhabit the [[ecological niche]]s near [[farm]]s, [[pasture]]s or other [[human settlement]]s — by employing human [[hunter]]s or [[trapping|trapper]]s to physically track down, kill and remove them from the area.  The culled animals, known as [[vermin]], may be targeted because they are deemed harmful to agricultural crops, livestock or facilities; serve as [[host (biology)|host]]s or [[vector (epidemiology)|vector]]s that [[transmission (medicine)|transmit]] [[pathogen]]s [[cross-species transmission|across species]] or [[zoonotic disease|to humans]]; or for [[population control]] as a mean of [[conservation biology|protecting]] other [[vulnerable species]] and [[ecosystem]]s.<ref>Tellman, Barbara. "Varmint control in Cochise County over the years." (2005)</ref>

Pest control via hunting, like all forms of harvest, has imposed an artificial [[Selective breeding|selective pressure]] on the organisms being targeted.  While varmint hunting is potentially selecting for desired [[ethology|behavioural]] and [[population ecology|demographic]] changes (e.g. animals avoiding human populated areas, crops and livestock), it can also result in unpredicted outcomes such as the targeted animal [[adaptation|adapting]] for [[r-selection|faster reproductive cycles]].<ref>Allendorf, Fred W.; Hard, Jeffrey J. "Human-induced evolution caused by unnatural selection through harvest of wild animals." ''Proceedings of the National Academy of Sciences'' 106. Supplement 1 (2009): 9987-9994</ref>