Editing Tsetse fly (section)

===Control techniques===
Many techniques have reduced tsetse populations, with earlier, crude methods recently replaced by methods that are cheaper, more directed, and ecologically better.

====Slaughter of wild animals====
One early technique involved slaughtering all the wild animals tsetse fed on. For example, the island of [[Principe]] off the west coast of Africa was entirely cleared of [[feral]] pigs in the 1930s, which led to the [[Local extinction|extirpation]] of the fly. While the fly eventually re-invaded in the 1950s, the new population of tsetse was free from the disease.<ref name="Headrick-2014">{{cite journal | last=Headrick | first=Daniel R. | editor-last=Büscher | editor-first=Philippe | title=Sleeping Sickness Epidemics and Colonial Responses in East and Central Africa, 1900–1940 | journal=[[PLOS Neglected Tropical Diseases]] | publisher=[[Public Library of Science]] | volume=8 | issue=4 | date=2014-04-24 | issn=1935-2735 | doi=10.1371/journal.pntd.0002772 | page=e2772 | pmid=24763309 | pmc=3998934 | s2cid=18378553| doi-access=free }}</ref><ref name="Costa-et-al-1915">{{cite book |date=30 March 1915 |title=Sleeping sickness - A record of four years' war against it in Principe, Portuguese West Africa |last1=Bruto da Costa |first1=Bernardo Francisco |last2=Sant' Anna |first2=José Firmino |last3=Correia dos Santos |first3=A. |last4=Araujo Alvares |first4=M. G. de |translator-last=Wyllie |translator-first=John Alfred |via=[[Internet Archive]] |url=https://archive.org/details/sleepingsickness00brutrich |access-date=2021-03-20}}</ref><ref name="WHO-tsetse-traps">{{cite web | url=http://www.who.int/tdr/publications/documents/tsetse_traps.pdf | title=STRATEGIC REVIEW OF TRAPS AND TARGETS FOR TSETSE AND AFRICAN TRYPANOSOMIASIS CONTROL|website=who.int | publisher=[[UNICEF]]/[[United Nations Development Programme|UNDP]]/[[World Bank]]/[[World Health Organization|WHO]]/Special Programme for Research and Training in Tropical Diseases |author=F.A.S. Kuzoe |author2=C.J. Schofield | date=2004}}</ref><ref name="McCowen-1913">{{ Cite journal | s2cid=44666631 | title=A Note on Sleeping Sickness in Principe Island and Angola, West Coast of Africa|journal=[[Proceedings of the Royal Society of Medicine]]| year=1913| last1=McCowen| first1=Surgeon| volume=6| issue=Sect Epidemiol State Med| pages=191–194| pmid=19977233| pmc=2006480| doi=10.1177/003591571300601409}}</ref>

====Land clearing====
Another early technique involved [[land clearing|complete removal of brush and woody vegetation from an area]].<ref name="Willett-1963" /> However, the technique was not widely used and has been abandoned.{{cn|date=November 2021}} Tsetse tend to rest on the trunks of trees so removing woody vegetation made the area inhospitable to the flies. Until about 1959 this was done by hand and so was quite time consuming. Glover et al 1959 describes the technique which they call "[[chain clearing]]". Chain clearing drags a chain forward between two heavy vehicles and thereby does the same job much more quickly - but still at some expense.<ref name="Willett-1963">{{cite journal | last=Willett | first=K. C. | title=Trypanosomiasis and the Tsetse Fly Problem in Africa | journal=[[Annual Review of Entomology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=8 | issue=1 | pages=197–214 | year=1963 | issn=0066-4170 | doi=10.1146/annurev.en.08.010163.001213 | pmid=14000804 }}</ref> Preventing regrowth of woody vegetation requires continuous clearing efforts which is even more expensive,<ref name="Willett-1963" /> and only practical where large human populations are present. Also, the clearing of woody vegetation has come to be seen as an environmental problem more than a benefit.{{cn|date=November 2021}}

====Pesticide campaigns====
[[Pesticides]] have been used to control tsetse starting initially during the early part of the twentieth century in localized efforts using the inorganic metal-based pesticides, expanding after the Second World War into massive aerial- and ground-based campaigns with organochlorine pesticides such as [[DDT]] applied as [[aerosol]] sprays at [[Ultra-Low Volume]] rates. Later, more targeted techniques used ''pour-on'' [[pesticide formulation|formulations]] in which advanced organic pesticides were applied directly to the backs of cattle.

====Trapping====
[[Image:TsetseTrap.jpg|right|thumb|Tsetse trap]]
Tsetse populations can be monitored and effectively controlled using simple, inexpensive [[trapping|traps]]. These often use blue cloth, either in sheet or biconical form, since this color attracts the flies. The traps work by channeling the flies into a collection chamber, or by exposing the flies to [[insecticide]] sprayed on the cloth. Early traps mimicked the form of cattle, as tsetse are also attracted to large dark colors like the hides of [[cow]]s and [[Bubalina|buffaloes]]. Some scientists put forward the idea that [[zebra]] have stripes, not as a camouflage in long grass, but because the black and white bands tend to confuse tsetse and prevent attack.<ref>{{cite news|last=Doyle-Burr |first=Nora |title=Scientists unravel mystery of zebra stripes |newspaper=Christian Science Monitor |url=http://www.csmonitor.com/Science/2012/0209/Scientists-unravel-mystery-of-zebra-stripes |access-date=May 15, 2012}}</ref><ref>{{Cite journal| title=Polarotactic tabanids find striped patterns with brightness and/or polarization modulation least attractive: An advantage of zebra stripes| journal=Journal of Experimental Biology| volume=215| issue=5| pages=736–745| year=2012| last1=Egri| first1=A.| last2=Blaho| first2=M.| last3=Kriska| first3=G.| last4=Farkas| first4=R.| last5=Gyurkovszky| first5=M.| last6=Akesson| first6=S.| last7=Horvath| first7=G.| pmid=22323196| doi=10.1242/jeb.065540| doi-access=free}}</ref>

The use of chemicals as attractants to lure tsetse to the traps has been studied extensively in the late 20th century, but this has mostly been of interest to scientists rather than as an economically reasonable solution. Attractants studied have been those tsetse might use to find food, like [[carbon dioxide]], [[octenol]], and [[acetone]]&mdash;which are given off in animals' breath and distributed downwind in an ''odor plume.'' Synthetic versions of these chemicals can create artificial odor plumes. A cheaper approach is to place cattle [[urine]] in a half gourd near the trap. For large trapping efforts, additional traps are generally cheaper than expensive artificial attractants.

A special trapping method is applied in [[Ethiopia]], where the BioFarm Consortium ([[ICIPE]], BioVision Foundation, BEA, Helvetas, [[DLCO-EA]], Praxis Ethiopia) applies the traps in a [[sustainable agriculture]] and [[rural development]] context (SARD). The traps are just the entry point, followed by improved farming, human health and marketing inputs. This method is in the final stage of testing (as of 2006).

====Sterile insect technique====
The [[sterile insect technique]] ('''SIT''') is a form of pest control that uses [[ionizing radiation]] ([[gamma ray]] or [[X-ray]]) to sterilize male flies that are mass-produced in special rearing facilities. The sterile males are released systematically from the ground or by air in tsetse-infested areas, where they mate with wild females, which do not produce offspring. As a result, this technique can eventually eradicate populations of wild flies. SIT is among the most [[environmentally friendly]] control tactics available, and is usually applied as the final component of an integrated campaign. It has been used to subdue the populations of many other fly species including the medfly, ''[[Ceratitis capitata]]''.

The sustainable removal of the tsetse fly is in many cases the most cost-effective way of dealing with the T&T problem resulting in major economic benefits for subsistence farmers in rural areas. Insecticide-based methods are normally very ineffective in removing the last remnants of tsetse populations, while, on the contrary, sterile males are very effective in finding and mating the last remaining females. Therefore, the integration of the SIT as the last component of an area-wide integrated approach is essential in many situations to achieve complete eradication of the different tsetse populations, particularly in areas of more dense vegetation.

A project that was implemented from 1994 to 1997 on the Island of [[Unguja]], [[Zanzibar]] (United Republic of [[Tanzania]]), demonstrated that, after suppression of the tsetse population with insecticides, SIT completely removed the ''[[Glossina austeni]]'' Newstead population from the Island.<ref name="Vreysen-et-al-2000">{{cite journal | last1=Vreysen | first1=Marc J. B. | last2=Saleh | first2=Khalfan M. | last3=Ali | first3=Mashavu Y. | last4=Abdulla | first4=Abdulla M. | last5=Zhu | first5=Zeng-Rong | last6=Juma | first6=Kassim G. | last7=Dyck | first7=V. Arnold | last8=Msangi | first8=Atway R. | last9=Mkonyi | first9=Paul A. | last10=Feldmann | first10=H. Udo | title=''Glossina austeni'' (Diptera: Glossinidae) Eradicated on the Island of Unguja, Zanzibar, Using the Sterile Insect Technique | journal=[[Journal of Economic Entomology]] | publisher=[[Oxford University Press]] (OUP) | volume=93 | issue=1 | date=2000 | issn=0022-0493 | pmid=14658522 | doi=10.1603/0022-0493-93.1.123 | pages=123–135 | s2cid=41188926| doi-access=free }}</ref><ref name="Caragata-et-al-2020">{{cite journal | last1=Caragata | first1=E.P. | last2=Dong | first2=S. | last3=Dong | first3=Y. | last4=Simões | first4=M.L. | last5=Tikhe | first5=C.V. | last6=Dimopoulos | first6=G. | title=Prospects and Pitfalls: Next-Generation Tools to Control Mosquito-Transmitted Disease | journal=[[Annual Review of Microbiology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=74 | issue=1 | date=2020-09-08 | issn=0066-4227 | doi=10.1146/annurev-micro-011320-025557 | pages=455–475| pmid=32905752 | s2cid=221625690 | doi-access=free }}</ref> This was carried out without any understanding of the [[population genetics]] of ''G. a.'', but future SIT efforts can benefit from such preparation. Population genetics would help to select the ''Glossina'' population to be deployed for similarity to the target population.<ref name="Krafsur-Ouma-2021">{{cite book | editor1-last=Dyck | editor1-first=Victor | editor2-last=Hendrichs | editor2-first=J. | editor3-last=Robinson | editor3-first=A. S. | title=Sterile Insect Technique Principles And Practice In Area-Wide Integrated Pest Management | publisher=[[CRC Press]] | year=2021 | isbn=978-1-000-37776-7 | oclc=1227700317 | language=en | chapter=4.1 - Role of Population Genetics in the Sterile Insect Technique | first1=E. S. | last1=Krafsur | first2=J. O. | last2=Ouma | pages=529–548/xv+1200}} {{ISBN|978-0-367-47434-8}} {{ISBN|978-1-003-03557-2}}</ref> The eradication of the tsetse fly from Unguja Island in 1997 was followed by the disappearance of the AAT which enabled farmers to integrate livestock keeping with cropping in areas where this had been impossible before. The increased livestock and crop productivity and the possibility of using animals for transport and traction significantly contributed to an increase in the quality of people's lives.<ref>{{cite journal |vauthors=Tambi EN, Maina OW, Mukhebi AW, Randolph TF |date=1999 |title=Economic impact assessment of rinderpest control in Africa |journal=Revue Scientifique et Technique de l'OIE |trans-journal=OIE Scientific and Technical Review |volume=18 |issue=2 |pages=458–477|doi=10.20506/rst.18.2.1164 |pmid=10472679 |doi-access=free }}</ref><ref>{{cite report |last=Mdoe |first=N. S. Y. |date=2003 |title=Livestock and agriculture development in Zanzibar, post-tsetse eradication: a follow-up socio-economic study |publisher=Report prepared for the International Atomic Energy Agency. IAEA |place=Vienna, Austria}}</ref> Surveys in 1999, 2002, 2014, and 2015 have confirmed this success - continued absence of tsetse and [[nagana]] on the island.<ref name="Zanzibar-20-years">{{cite web | title=Tsetse Free for 20 Years Thanks to a Nuclear Technique: The Island of Unguja, Zanzibar | website=[[International Atomic Energy Agency|IAEA]] (International Atomic Energy Agency) | date=2016-10-24 | url=https://www.iaea.org/newscenter/news/tsetse-free-for-20-years-thanks-to-a-nuclear-technique-the-island-of-unguja-zanzibar | access-date=2021-11-17}}</ref>

In the [[Niayes]] region of [[Senegal]], a coastal area close to [[Dakar]], livestock keeping was difficult due to the presence of a population of ''[[Glossina palpalis gambiensis]]''. Feasibility studies indicated that the fly population was confined to very fragmented habitats and a population genetics study indicated that the population was genetically isolated from the main tsetse belt in the south eastern part of Senegal. After completion of the feasibility studies (2006–2010), an area-wide integrated eradication campaign that included an SIT component was started in 2011, and by 2015, the Niayes region had become almost tsetse fly free. This has allowed a change of [[cattle breed]]s from lower producing [[trypanotolerant]] breeds to higher-producing foreign breeds.<ref>{{cite web |title=The Tsetse Fly Eradication Project in Senegal Wins Award for Best Sustainable Development Practices |date=23 July 2015 |url=https://www.iaea.org/newscenter/news/tsetse-fly-eradication-project-senegal-wins-award-best-sustainable-development-practices|access-date=12 November 2020|website=Iaea.org}}</ref><ref>{{cite news |last=Paquette |first=Danielle |date=2019-05-31 |title=A U.S.-funded nuclear project to zap a killer fly into extinction is saving West Africa's cows |url=https://www.washingtonpost.com/world/africa/a-us-funded-nuclear-project-to-zap-a-killer-fly-into-extinction-is-saving-west-africas-cows/2019/05/31/12f92626-7713-11e9-a7bf-c8a43b84ee31_story.html |newspaper=[[The Washington Post]] |access-date=2019-06-01}}</ref>

The entire target area (Block 1, 2 and 3) has a total surface of {{convert|1000|km2|sqmi}}, and the first block (northern part) can be considered free of tsetse, as intensive monitoring has failed to detect since 2012 a single wild tsetse fly. The prevalence of AAT has decreased from 40 to 50% before the project started to less than 10% to date in blocks 1 and 2. Although insecticides are being used for fly suppression, they are applied for short periods on traps, nets and livestock, and are not spread into the environment. After the suppression activities are completed, no more insecticide is applied in the area. The removal of trypanosomosis will eliminate the need for constant prophylactic treatments of the cattle with trypanocidal drugs, therefore reducing [[residue (chemistry)|residue]]s of these drugs in the [[Feces|dung]], meat and milk.

The main beneficiaries of the project are the many small holder farmers, the larger commercial farms and the consumers of meat and milk. According to a socio-economic survey and benefit cost analysis,<ref>{{cite journal |last1=Bouyer |first1=F |last2=Seck |first2=MT |last3=Dicko |first3=AH |last4=Sall |first4=B |last5=Lo |first5=M |last6=Vreysen |first6=MJB |last7=Chia |first7=E |last8=Bouyer |first8=J |last9=Wane |first9=A |display-authors=5 |year=2014 |title=Ex-ante Benefit-Cost Analysis of the Elimination of a Glossina palpalis gambiensis Population in the Niayes of Senegal |journal=PLOS Negl Trop Dis |volume=8 |issue=8| page=e3112 |doi=10.1371/journal.pntd.0003112 | pmid=25144776 |pmc=4140673 |doi-access=free}}</ref> after eradication of the tsetse farmers will be able to replace their local breeds with improved breeds and increase their annual income by €2.8 million. In addition, it is expected that the number of cattle will be reduced by 45%, which will result in reduced environmental impacts.