These defenses limit the population of infected flies. Consequently, more than half of the total tsetse population lives under the ground as pupae. The tsetse fly is known for being the sole vector of the african trypanosomes trypanosoma brucei rhodesiense and t. Female house flies favor damp, dark surfaces such as compost, manure and. The proboscis also serves as the developmental site for the infective metacyclic. The life cycle of most trypanosomes species is digenetic. Male flies settle on the back of the female, and the claspers. At this stage of the life cycle the parasites are in their infective form, called. At first glance, it may be surprising why tsetse flies aren. During a warm summer optimal conditions for a housefly the cycle, from fertilized egg to adult, spans a mere seven to 10 days. Human african trypanosomiasis, also known as sleeping sickness, is a vectorborne parasitic disease. Within the midgut of the tsetse fly, a separate series of cell surface molecules known as procyclins dominate the cell membrane. Microarchitecture of the tsetse fly proboscis parasites. The tsetse fly becomes infected with bloodstream trypomastigotes when taking a blood meal on an infected mammalian host.
The twentytwo species of bloodfeeding tsetse fly are found only in tropical africa all can carry the trypanosome parasite that causes african. The word tsetse means fly in tswana, and refers to all 23 species of the fly genus glossina. The female tsetse fly does not lay eggs but produces larvae, one at a time. Singlecell rna sequencing of trypanosoma brucei from tsetse. This life cycle, with a slow reproductive rate and substantial parental investment in the care of young, is a relatively unusual example of an insect with a socalled ktype life history. The life cycles of these trypanosomes in the fly were described in the last century, but comparatively few details are available for trypanosoma nannomonas congolense, despite the fact that it is probably the most prevalent and widespread pathogenic species for. Over a period of a few days, she will produce five or six batches of eggs. This film gives a detailed account of the lifecycle of the tsetse fly, with special reference to glossina morsitans. In addition to the bite of the tsetse fly, the disease can be transmitted by. Travelers who go to subsaharan africa are at risk see map. The life cycle of the tsetse fly educational film wiki. The fly harbors three symbionts, wigglesworthia glossinida, sodalis glossinidius, and wo.
The life cycle of the tsetse fly is a 1987 film about the life cycle of the tsetse fly. The twentytwo species of bloodfeeding tsetse fly are found only in tropical africa all can carry the trypanosome. Here we will look at the morphology, life cycle, and spatial distribution of the tsetse fly and how these factors make it an ideal. Trypanosomiasis circulatory system merck veterinary manual. A bite from this fly puts you into a deadly sleep bbc.
Mast parts are hard, but some areas remain flexible, especially the base of the wing, the joints on things and where the mouth parts join on to the head. A life cycle of the tsetse fly, b viviparous reproduction cycle of. The tsetse fly is attracted to the dust that moving vehicles and wild animals create. The mating of tsetse flies probably takes place near to or on host animals.
Travelers who plan to spend a lot of time outdoors or. The tsetsetransmitted african trypanosomes cause diseases of importance to the health of both humans and livestock. Trypanosoma brucei gambiense accounts for more than 98% of reported cases. These advantageous vsg coats are only found within the metacyclic stages of the trypanosomes life cycle which exist only in the salivary gland of the tsetse fly and in the mammalian host bloodstream. Male flies settle on the back of the female, and the claspers at the posterior end of the male abdomen grip the end of the female abdomen. They are transmitted to humans by tsetse fly glossina genus bites which have acquired their infection from human beings or from animals harbouring human pathogenic parasites.
It is believed to have evolved in the cenozoic era, possibly in the middle east, and has spread all over the world as a commensal of humans. The life cycle of a tsetse fly a bloodengorged female e fly emerging from the puparium b larvipositing female f lateral aspect of a tsetse fly c third instar larva g dorsal aspect of a tsetse fly d puparium containing the pupa h some hosts of the morsitans group of tsetse flies e fly emerging from the puparium. The intermediate host is blood sucking insect called tsetse fly. Tsetse flies genus glossina are restricted to africa from about latitude 15n to 29s.
For a more detailed description of the life cycle and general biology of tsetse flies, see. Sep 23, 2014 this film gives a detailed account of the life cycle of the tsetse fly. Tsetse fly simple english wikipedia, the free encyclopedia. Adults are gray to black, with four dark, longitudinal lines on the thorax, slightly hairy bodies, and a single pair of membranous wings. Download scientific diagram a life cycle of the tsetse fly, b viviparous reproduction cycle of tsetse flies. A detailed account of the lifecycle of the tsetse fly, with special reference to glossina morsitans. Tsetse flies have an arsenal of immune defenses to resist each stage of the trypanosome infectious cycle, and thus are relatively refractory to trypanosome infection among the host flies defenses is the production of hydrogen peroxide, a reactive oxygen species that damages dna. Trypanosomiasis is transmitted to man and animals by a blood sucking insect, the tsetse fly. Structure and life cycle of trypanosome with diagram. The adult fly emerges from the pupa in the ground after about 30 days. Jun 27, 2012 the tsetse transmitted african trypanosomes cause diseases of importance to the health of both humans and livestock. Tsetse biology, systematics and distribution, techniques.
A bite from a tsetse fly is an extremely unpleasant experience. Symptoms include fatigue, high fever, headaches, and muscle aches. Man and domestic animals serve as primary host and bloodsucking insect, the tsetse fly serve as the intermediate host fig. This film gives a detailed account of the life cycle of the tsetse fly, with special reference to glossina morsitans. Female house flies favor damp, dark surfaces such as compost, manure and other decomposing organic material for egg laying. The intermediate host is blood sucking insect called tsetse fly glossina palpalis. The life cycles of these trypanosomes in the fly were described in the last century, but comparatively few details are available for trypanosoma nannomonas congolense, despite the fact that it is probably the most prevalent and widespread pathogenic species for livestock in. The tsetse fly has a quite unusual lifecycle for an insect. The life cycle of a house fly begins in the egg stage.
The entire life cycle of african trypanosomes is represented by extracellular stages. African trypanosomiasis, also called african sleeping sickness, is a parasitic disease spread by the tsetse fly. Tsetse flies feed on the blood of vertebrate animals including humans and in doing so, transmit the sleeping sickness parasite from infected animals to uninfected ones. The tsetse fly lives in nearly 10,000,000 square kilometres 4,000,000 sq mi in subsaharan africa mostly wet tropical forest and many parts of this large area is fertile land that is left uncultivateda socalled green desert not used by humans and cattle. Sleeping sickness is characterized by two stages of illness. It is caused by infection with protozoan parasites belonging to the genus trypanosoma. The whole of the body is covered with cuticle, even the eyes. Here we will look at the morphology, life cycle, and spatial distribution of the. The entire life cycle of the fly takes about three weeks.
The life cycle of trypanosoma nannomonas congolense in the. The pan african trypanosomosis and tsetse eradication campaign pattec were borne. Tsetse flies include all the species in the genus glossina while tsetse flies resemble house flies, having a similar size ranging from 8 to 17 mm, two anatomical characteristics make them easily distinguishable while resting. Human african trypanosomiasis takes 2 forms, depending on the parasite involved. The sperm remains active for the rest of the females life. Dont ride in the back of jeeps, pickup trucks or other open vehicles. Adult females mate only once during their lifetime, although males can mate more than once. Identification of the meiotic life cycle stage of trypanosoma. A female house fly is capable of laying up to 150 eggs in a batch. During this time, the female feeds the developing offspring with a milky substance secreted by a.
Most of the 37 countries infested with tsetse are poor, debtridden and underdeveloped. The tsetse fly has a quite unusual life cycle for an insect. The life cycle in the tsetse may be as short as 1 wk with t vivax or extend to a few weeks for t brucei spp. During this time, the female feeds the developing offspring with a milky substance secreted by a modified gland in the uterus. The twentytwo species of bloodfeeding tsetse fly are found only in tropical africa all can carry the trypanosome parasite that causes african sleeping sickness african trypanosomiasis in man and nagana in cattle and other domesticated animals. The low reproductive rate in tsetse is compensated by the extreme protection given to each larva by the female, but it also makes the impact of any loss of female flies greater than in species with a mass production of eggs krinsky, 2002. The tsetse fly is less active during the hottest period of the day. Bbc earth a bite from this fly puts you into a deadly sleep. Man and domestic animals becomes infected by the bite of tsetse fly. The mammals, like pigs, buffaloes, antelopes often act as reservoir hosts harbouring the parasite. Tsetse anatomy has been well described, including detailed accounts of the functional anatomy of the proboscis for piercing host skin and sucking up blood.
The life cycle of the tsetse fly 1987 entire title. Tsetse fly, genus glossina, any of about two to three dozen species of bloodsucking flies in the housefly family, muscidae order diptera, that occur only in africa and transmit sleeping sickness african trypanosomiasis in humans and a similar disease called nagana in domestic animals. Tsetse flies genus glossina are large bloodsucking dipteran flies that are important as vectors of human and animal trypanosomiasis in subsaharan africa. This film gives a detailed account of the life cycle of the tsetse fly. Sleeping sickness, also called african trypanosomiasis, disease caused by infection with the flagellate protozoan trypanosoma brucei gambiense or the closely related subspecies t. Identification of the meiotic life cycle stage of trypanosoma brucei in the tsetse fly lori peacock, vanessa ferris, reuben sharma, jack sunter, mick bailey, mark carrington, wendy gibson proceedings of the national academy of sciences mar 2011, 108 9 367676. Female tsetse only fertilize one egg at a time and keep each egg in their uterus while the offspring develops internally during the first larval stages. The housefly musca domestica is a fly of the suborder cyclorrhapha. The twentytwo species of bloodfeeding tsetse fly are found only in tropical africa all can. Nov 19, 2009 a detailed account of the life cycle of the tsetse fly, with special reference to glossina morsitans. The adult male deposits a large ball of sperm directly into the uterus of the female, which travels into the spermathecae. Mar 01, 2011 identification of the meiotic life cycle stage of trypanosoma brucei in the tsetse fly lori peacock, vanessa ferris, reuben sharma, jack sunter, mick bailey, mark carrington, wendy gibson proceedings of the national academy of sciences mar 2011, 108 9 367676. Trypanosoma equiperdum definition of trypanosoma equiperdum by.
Tsetse use a combination of smell and sight to locate their hosts, and the relative importance of these cues varies between species. Dec 19, 2016 a bite from a tsetse fly can infect you with a terrifying parasite that brings on a deep and possibly fatal sleep. The life cycle of trypanosoma nannomonas congolense in. The tsetse transmitted african trypanosomes cause diseases of importance to the health of both humans and livestock. Like all other insects, the tsetse fly has a tough outer covering or cuticle. Identification of the meiotic life cycle stage of trypanosoma brucei in the tsetse fly lori peacock, a, b vanessa ferris, a, b reuben sharma, c, 1 jack sunter, c mick bailey, b mark carrington, c and wendy gibson a, 2. The trypanosome parasite is first introduced into the mammalian host when a tsetse fly takes a blood meal and secretes parasitefilled saliva into the hosts skin. The housefly life cycle closely mirrors that of most insects. Most invertebrates have a reproductive strategy that involves producing large numbers of offspring to offset losses through predation and to enable rapid increases in population whenever possible. The people most exposed to the tsetse fly and to the disease live in rural areas and depend on agriculture, fishing, animal husbandry or hunting. This slow rate of reproduction means that tsetse populations can be eradicated by killing just 23% of the female population per day. The life cycle of tsetse is complicated and rather unique 10. It is not like a mosquito, which can furrow its thin mouthpart directly into your blood, often without you noticing. The life cycle of the tsetse fly educational film wiki fandom.
358 995 1293 918 821 616 196 1155 476 729 1141 1105 761 702 598 442 1113 1266 1257 54 1024 1307 176 475 941 734 953 34 1047 1341 1110 79 91 133 1172 1260 1330 626 293 893 103 633 1166 1216 999 1490