Sterile insect technology

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The technique was first used against the New World screw worm fly ( Cochliomyia hominivorax ).

Sterile insect technique (English sterile insect technology , SIT), also Autozidmethode or self-destruction method called, is a method to populations of insect pests by means of a large number decimate sterile individuals or exterminating. The artificially produced and sterilized individuals are released in the target area, mate with fertile females and reduce the likelihood that offspring will be successfully produced. In contrast to insecticides , which can also destroy beneficial insects and cause major environmental damage , the effect is limited to the insect species affected. Another advantage of the technology is that people are helped in the same way regardless of their income, in contrast to buying medicines, for example . In principle, symptoms of resistance can develop if females who allow multiple mating are positively selected. So far, however, very few such cases are known, of which only one is sufficiently documented.

The SIT is being developed as part of a research program by the FAO and IAEA .

method

The insect pests are bred in the laboratory, and the males are sterilized with ionizing radiation , chemosterilants or genetic engineering so that they can no longer produce offspring . The sterile males are released in large numbers in the target area and compete for the females with the non-sterile males living in nature. If the number of sterile animals is high enough, the probability that a female will be mated by a sterile male and thus not have any offspring is so high that the population is greatly reduced or even disappears completely. During the sterilization, however, the individuals must not be damaged in their ability to mate or compete, so that they do not suffer any disadvantages compared to naturally occurring individuals. However, legal framework conditions often prevent genetically modified individuals from being released.

History and areas of application

The technique was developed by Raymond C. Bushland and Edward F. Knipling in the late 1930s on the basis of Knipling's idea when both were looking for an alternative to chemical pesticides. At that time, the parasitic larvae of the New World screwworm fly ( Cochliomyia hominivorax ) were causing significant livestock losses in southern North America. The species was almost extinct in the early 1950s in the course of the first tests with the SIT in Sanibel , Florida . In the 1960s and 70s, thanks to SIT, the screwworm fly populations in the USA were kept under control. To this end, up to 50 million sterilized insects were released every week by air. The Mediterranean fruit fly ( Ceratitis capitata ) has also been successfully combated in California with comprehensive SIT programs . In 1992 Knipling and Bushland received the World Food Prize .

The SIT also combats disease carriers such as the tsetse flies ( Glossina ssp.) Or anopheles mosquitoes . For example, by 1997 the tsetse fly and the sleeping sickness it transmitted was eradicated on the island of Zanzibar .

Web links

Individual evidence

  1. a b Horst Börner et al .: Plant diseases and plant protection . Springer-Verlag , Berlin, Heidelberg 2009, ISBN 978-3-540-49067-8 ( limited preview in the Google book search).
  2. Luc Alphy: Sex to Extinction - With sterile insects against dangerous mosquitoes in the science series in the focus of the Deutschlandfunk . Retrieved October 1, 2010.
  3. Brockhaus Encyclopedia . Brockhaus GmbH, Mannheim 2006, Volume 3, p. 31.
  4. L. Alphey, M. Benedict u. a .: Sterile-insect methods for control of mosquito-borne diseases: an analysis. In: Vector borne and zoonotic diseases. Volume 10, number 3, April 2010, ISSN  1557-7759 , pp. 295-311, doi : 10.1089 / vbz.2009.0014 , PMID 19725763 , PMC 2946175 (free full text).
  5. Manfred Fortmann: The great cosmos book of beneficial insects. Franckh-Kosmos Verlags-GmbH & Co., Stuttgart 2000, ISBN 3-440-06588-X , p. 283.
  6. a b Volkart Wildermuth : Sex bis zum Aussterben , Deutschlandfunk , Wissenschaft im Brennpunkt , accessed on October 1, 2010.
  7. a b The World Food Prize for 1992 : Short biography of Raymond C. Bushland and Edward F. Knipling and information on SIT (English). Retrieved October 1, 2010.
  8. Thomas M. Smith et al.: Ecology . Pearson Education Deutschland GmbH, Munich 2009, ISBN 978-3-8273-7313-7 . P. 286