Editing Pyrethrin (section)

==Use as an insecticide==
Pyrethrin is most commonly used as an [[insecticide]] and has been used for this purpose since the 1900s.<ref name=Ullmann/> In the 1800s, it was known as "[[Persian powder]]", "Persian pellitory", and "zacherlin". Pyrethrins delay the closure of [[sodium channel#Voltage-gated|voltage-gated sodium channel]]s in the nerve cells of insects, resulting in repeated and extended nerve firings. This hyperexcitation causes the death of the insect due to loss of motor coordination and paralysis.<ref>"Pyrethrins General Fact Sheet." National Pesticide Information Center (n.d.): n. pag. Nov. 2014. Web. 26 Apr. 2015. <http://npic.orst.edu/factsheets/pyrethrins.pdf></ref> Resistance to pyrethrin has been bypassed by pairing the insecticide with synthetic synergists such as [[piperonyl butoxide]]. Together, these two compounds prevent detoxification in the insect, ensuring insect death.<ref>"Pyrethrin." Asktheexterminator.com. Ask the Exterminator, 2011. Web. 2 Apr. 2015. <http://www.asktheexterminator.com/Pesticide/Pyrethrin.shtml {{Webarchive|url=https://web.archive.org/web/20110904125404/http://www.asktheexterminator.com/Pesticide/Pyrethrin.shtml |date=2011-09-04 }}></ref> Synergists make pyrethrin more effective, allowing lower doses to be effective. Pyrethrins are effective insecticides because they selectively target insects rather than mammals due to higher insect nerve sensitivity, smaller insect body size, lower mammalian skin absorption, and more efficient mammalian hepatic metabolism.<ref name=pmid16180929>{{cite journal |pmid=16180929 |year=2005 |last1=Bradberry |first1=S. M. |title=Poisoning due to pyrethroids |journal=Toxicological Reviews |volume=24 |issue=2 |pages=93–106 |last2=Cage |first2=S. A. |last3=Proudfoot |first3=A. T. |last4=Vale |first4=J. A. |doi=10.2165/00139709-200524020-00003 }}</ref> Also, mammals are able to process pyrethrin quickly and have higher body temperatures which prevent pyrethrin from working effectively <ref name=":02">{{cite book |doi=10.1016/B978-0-12-811410-0.00039-8 |chapter=Pyrethrins and Pyrethroids |title=Veterinary Toxicology |date=2018 |last1=Ensley |first1=Steve M. |pages=515–520 |isbn=978-0-12-811410-0 }}</ref>

Although pyrethrin is a potent insecticide, it also functions as an [[insect repellent]] at lower concentrations. Observations in food establishments demonstrate that flies are not immediately killed, but are found more often on windowsills or near doorways. This suggests, due to the low dosage applied, that insects are driven to leave the area before dying.<ref>Todd, G Daniel, David Wohlers, and Mario Citra. "Toxicological Profile for Pyrethrins and Pyrethroids." ATSDR. Agency for Toxic Substances and Disease Registry, Sept. 2001. Web. 26 Apr. 2015. <http://www.atsdr.cdc.gov/ToxProfiles/tp155.pdf></ref> Because of their insecticide and insect repellent effect, pyrethrins have been very successful in reducing insect pest populations that affect humans, crops, livestock, and pets, such as ants, spiders, and lice, as well as potentially disease-carrying mosquitoes, fleas, and ticks.

As pyrethrins and pyrethroids are increasingly being used as insecticides, the number of illnesses and injuries associated with exposure to these chemicals is also increasing.<ref>{{cite journal |doi=10.1007/BF03160917 |pmid=18072143 |pmc=3550062 |title=Pyrethrin and pyrethroid exposures in the United States: A longitudinal analysis of incidents reported to poison centers |journal=Journal of Medical Toxicology |volume=3 |issue=3 |pages=94–9 |year=2007 |last1=Power |first1=Laura E. |last2=Sudakin |first2=Daniel L. }}</ref> However, few cases leading to serious health effects or mortality in humans have occurred, which is why pyrethroids are labeled "low-toxicity" chemicals and are ubiquitous in home-care products.<ref name=pmid16180929/> Pyrethrins are widely regarded as better for the environment, and can be harmless if used only in the field with localized sprays, as UV exposure breaks them down into harmless compounds. Additionally, they have little lasting effect on plants, degrading naturally or being degraded by the cooking process.<ref>{{cite book |last=Vettorazzi |first=G. |year=1979 |title=International Regulatory Aspects for Pesticide Chemicals |url=https://archive.org/details/internationalreg02vett |url-access=registration |pages=[https://archive.org/details/internationalreg02vett/page/89 89–90] |publisher=CRC Press|isbn=9780849356070 }}</ref>

Specific pest species that have been successfully controlled by pyrethrum include: potato, beet, grape, and six-spotted leafhopper, cabbage looper, celery leaf tier, Say's stink bug, twelve-spotted cucumber beetle, lygus bugs on peaches, grape and flower thrips, and cranberry fruitworm.<ref>Caldwell, Brian, Eric Sideman, Abby Seaman, Anthony Shelton, and Christine Smart. "Resource Guide for Organic Insect and Disease Management." (n.d.): n. pag. Cornell University, 2013. Web. 23 Mar. 2015. <http://web.pppmb.cals.cornell.edu/resourceguide/pdf/resource-guide-for-organic-insect-and-disease-management.pdf></ref>