Repellent

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Cow horn oil jar for insect repellent pitch oil, a by-product of the distillation of tree bark from Ranea, Norrbotton, Sweden . Since 1921 in the Nordic Museum , Stockholm. The vessel was carried on the belt by means of a leather loop.

A repellent (from the Latin repellere, "drive away", " push back") - also repellant , repulsive or deterrent - is an active ingredient that is usually perceived by an organism through its sense of smell and that scares it off without killing it. Oral intake of the active ingredient, i.e. an effect via the sense of taste, is possible and takes place e.g. B. in the deterrence of wild boars application.

In the English-speaking world in particular, repellants also include physical methods that drive away or repel organisms, such as electric pasture fences or ultrasonic sources ( repellers ).

Repellants are used against various organisms that are viewed by the user as “harmful organisms” or as undesirable organisms in a certain location. Today, arthropods , fish, mammals or humans can be considered as target organisms .

Defense against stinging insects is a strong human need in many areas. In the Nordic countries, which are very polluted with mosquitoes in summer, pitch oil, a by-product from the extraction of birch pitch , is a traditional agent.

Repellants against arthropods

This group of repellants is mainly used against blood-sucking, disease-transmitting arthropods such as mosquitoes , horseflies and ticks . You should keep these organisms away from humans and animals, and rarely from plants.

As natural repellents, especially essential oils of various representatives of the will mint (mainly basil , mint , lavender , sage or thyme ), the myrtle ( eucalyptus , clove and tea tree ), the aromatic grasses ( citronella and palmarosa ) and the geraniums and cedar used . The deterrent effect of essential oils is only brief, however, especially when they are used in dilution. The Stiftung Warentest tested in 2004, including five repellents whose main ingredients were blends of essential oils. The remedies were either completely ineffective or protected against mosquito bites for less than an hour on average. The tests in 2010 also examined five products based on essential oils. A remedy with geraniol protected against bites for one to three hours, depending on the type of mosquito, another with a mixture of essential oils one to a good two and a half hours. The other three products do not protect or protect for less than an hour. In 2014, repellents were tested against the diurnal yellow fever mosquito, the southern house mosquito (Culex quinquefasciatus), and the malaria mosquito (Anopheles gambiae) with the result that one agent with the active ingredient Icaridin and two with the active ingredient DEET work best against all. Among the herbal active ingredients , p-menthane-3,8-diol (PMD, citriodiol), derived from lemon eucalyptus ( Corymbia citriodora , syn. Eucalyptus citriodora ), is the most effective to date. Depending on the formulation, it can guarantee protection times of several hours. Originally obtained from the distillation residues after the extraction of the essential oil from lemon eucalyptus ( Corymbia citriodora , syn. Eucalyptus citriodora ), it is now often also chemically synthesized. PMD is not a component of the essential oil of lemon eucalyptus.

Artificial repellants against arthropods are, for example, diethyltoluamide (DEET), icaridine (picaridine), N- butyl acetanilide , di-n-propyl isocinchomeronate , indalone , sigillins , SS220 , 2-butyl-2-ethyl-1,3-propanediol or IR3535 (= ethylbutylacetylaminopropionate ). Depending on the product and formulation, protection times of several hours against mosquitoes could be observed with these active ingredients. Repellent preparations for use on the skin are available in the product forms solution , aerosol spray, pump spray, foam, stick, roller , emulsion, gel and as impregnated wipes. The most important products - solutions, sprays and emulsions - are based on alcoholic or aqueous-alcoholic solutions or cosmetic emulsions. Caring and moisture-binding substances and perfume components improve the cosmetic properties.

In dogs, the pyrethroid permethrin, which is effective as an insecticide but also disgusts arthropods, is used as a spot-on against fleas and ticks . Pyrethroids are synthetically produced varieties of pyrethrum , which occurs naturally in chrysanthemums . They are also used to make bed nets or items of clothing a deterrent to arthropods.

Arthropod repellants are an important preventive measure against infections in regions with a high risk of the transmission of pathogens. In the temperate zones of Europe, the use of tick repellants is a useful protective measure, in addition to almost completely covering the skin with clothing and TBE vaccination .

Shark repellants

World War II is considered to be the first epoch of serious research into shark repellants . At that time, the military tried to minimize the apparent or real risk for aircraft crews who were thrown into the water or seafarers in distress. The research, along with historical experience, found that sharks are effectively driven away by the "smell" of dead sharks. Certain copper compounds such as copper sulfate and copper acetate appeared to be the decisive components of this smell . These compounds were mixed with other ingredients designed to mimic the scent of a dead shark's body to protect people in the water. For years, a preparation of copper acetate and dyes was common as a shark repellent for seafarers. Later research has shown that this preparation was nearly ineffective for its intended purpose.

Even today, people are still looking for an effective shark repellent. So far, however, physical measures have proven to be most effective, such as devices that disrupt the sharks' sensitive lateral line organ through electrical fields .

Repellants against mammals

Repellants are basically based on the principle of exploiting an animal's natural aversion to something. The selected object of aversion is usually something that the animal has learned to avoid in its natural environment or which it instinctively avoids. Some animals are scared off by anything that carries the odor of the urine of a particular predator . The urine of a tiger is a very effective repellent against many mammals. Coyote urine has taken on a role in deterring deer . The smell of urine from foxes is effective to rabbits , woodchucks , squirrels and chipmunks to drive. The urine of bobcats worries moles , mice , voles and other rodents . The smell of wolf urine drives moose away .

There are animals that try to protect themselves with repellants. They spread, mostly when attacked, substances that are characterized by a disgusting smell. They include B. certain bed bugs like the bed bug or the green stink bug . The most prominent representatives of this group, however, are the skunks or skunks . To defend themselves, they inject an odor-intensive anal gland secretion, which mainly contains the alkanethiols (also known as mercaptans) ( E ) -2-butene-1-thiol and 3-methylbutanethiol as repellants . The active ingredients of the anal gland secretion are now produced synthetically and used in preparations to scare dogs and cats, and in individual cases also against humans.

Other synthetically produced repellants are

There is a large assortment in specialist shops to protect against game browsing and rooting damage from forest animals such as roe deer , red deer and wild boar . There are granulates and liquid products, some of which are chemically based on the exhalation of predators and some on human sweat . Liquid means are applied in evaporators, granules can be scattered. The funds are either applied over a large area or more often as a scented fence .

See also

Individual evidence

  1. ^ Partial definition according to: Matthias Schaefer: Dictionary of Ecology . Spectrum Academic Publishing House, Heidelberg 2003. ISBN 3-8274-0167-4 .
  2. http://www.sacredearth.com/ethnobotany/plantprofiles/birch.php
  3. Compare the explanatory text in the showcase: https://commons.wikimedia.org/wiki/File:Oil_Jar_in_cow_horn_for_mosquito-repelling_pitch_oil.JPG
  4. ^ S. Moore, A Lenglet & N. Hill (2007): Plant-based Insect Repellents. In: Insect Repellents: Principles, Methods, and Uses . Edited by M. DEbboun, SP Frances & D. Strickman. Boca Raton, London, New York: CRC Press. ISBN 978-0-8493-7196-7 .
  5. Stiftung Warentest: Test mosquito repellent (2004)
  6. a b Stiftung Warentest: Test Mosquito Repellent (2010) .
  7. Mosquito repellants: Only 4 out of 21 protect well , Stiftung Warentest, June 13, 2014.
  8. SP Carroll & J. Loye (2006): PMD, a registered botanical repellent with DEET-like efficacy. Journal of the American Mosquito Control Association, 22: 507-514.
  9. SJ Moore et al. (2007): A low-cost repellent for malaria vectors in the Americas: results of two field trials in Guatemala and Peru. Malaria Journal 6. doi : 10.1186 / 1475-2875-6-101
  10. ^ A b A. Rose & U. Kröckel: Prevention of vectorially transmitted infections. In: B. Rieke, Th. Küpper & CM Muth (eds.): Modern travel medicine. Handbook for doctors, pharmacists, travelers. Gentner Verlag, Stuttgart 2010, 326–337. ISBN 978-3-87247-708-8 (book chapters available online) .
  11. ^ Umbach, Wilfried: Cosmetics and Hygiene , 3rd edition, WILEY-VCH Verlag Weinheim, 173–177 (2004).
  12. http://www.siepmann.net/Weidezaunzubeh%C3%B6r/Wildabwehr/Wildschreck_Granulat.html
  13. http://www.porocol.de/pdf/reierungen/uj_testbericht_maerz08.pdf
  14. Archived copy ( Memento of the original from January 12, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / bega-tierzuchtbedarf.de

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