Rhodnius prolixus

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Rhodnius prolixus
Rhodnius prolixus.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Suborder: Heteroptera
Family: Reduviidae
Genus: Rhodnius
Species:
R. prolixus
Binomial name
Rhodnius prolixus
Stål, 1859

Rhodnius prolixus is the principal triatomine vector of the Chagas parasite due to both its sylvatic and domestic populations in northern South America as well as to its exclusively domestic populations in Central America. It has a wide range of ecotopes, mainly savanna and foothills with an altitude of between 500 and 1,500 metres (1,640 and 4,921 ft) above sea level and temperatures of 16 to 28 °C (61 to 82 °F). Sylvatic R. prolixus, as virtually all Rhodnius spp., is primarily associated with palm tree habitats and has a wide range of hosts including birds, rodents, marsupials, sloths, and reptiles.

Contents

The insect was used by Sir Vincent Wigglesworth for the detection of insect hormones. It has been implicated in the transmission of transposons between it and some of its vertebrate hosts, squirrel monkeys and opossums. [1]

Rhodnius prolixus is also known as the kissing bug (like other triatomine bugs) because it tends to feed on the area around victims' mouths. [2]

History

Rhodnius prolixus established itself throughout Central America after specimens that originated in Venezuela accidentally escaped from a San Salvadoran research laboratory in 1915. It colonized houses and invaded neighboring countries, probably through accidental carriage by travelers. [3]

Life cycle

The insect has five larval stages, with a moult between each. Each larval stage consumes a single large meal of blood, which triggers the moulting process, 12–15 days later. Wigglesworth demonstrated that the moult is started by prothoracicotropic hormone (PTTH) secreted into the blood in response to hormone release by neurosecretory cells in the brain. [4] Further it was demonstrated that the corpora allata secrete the juvenile hormone which prevents the premature development into an adult. The removal of the head during any larval stage causes early development into an adult, whereas the implantation of a juvenile head during the fifth larval stage results in a giant sixth stage larva. [5]

The adult secretes compounds into the wound during feeding, including lipocalins. These lipocalins were demonstrated to serve various functions including sequestering amines – especially serotonin – to prevent vasoconstriction (and possibly coagulation) in the host by Andersen et al. 2003. [6] The male reproductive system of R. prolixus contains four accessory glands, three which are responsible for producing the spermathecae and one which is responsible for the movement of spermatozoa from the spermatophore into the female. Once mating occurs, the sperm move through the reproductive system of the female through peristatic waves. The female then stores the sperm until fertilization. [7]

As disease vector

Chagas disease is caused by the parasitic protozoan Trypanosoma cruzi . Infection with Chagas disease occurs after Rhodnius releases protozoans in its feces immediately following a blood meal. The parasite enters the victim through the bite wound after the human host scratches the bite. Infection may also occur via blood transfusion and ingestion of food contaminated with kissing bug feces.[ citation needed ]

Rhodnius prolixus - range of nymph stages through to adult Rp-nymphs-adult.JPG
Rhodnius prolixus – range of nymph stages through to adult

See also

Related Research Articles

<span class="mw-page-title-main">Chagas disease</span> Mammal parasitic disease

Chagas disease, also known as American trypanosomiasis, is a tropical parasitic disease caused by Trypanosoma cruzi. It is spread mostly by insects in the subfamily Triatominae, known as "kissing bugs". The symptoms change over the course of the infection. In the early stage, symptoms are typically either not present or mild, and may include fever, swollen lymph nodes, headaches, or swelling at the site of the bite. After four to eight weeks, untreated individuals enter the chronic phase of disease, which in most cases does not result in further symptoms. Up to 45% of people with chronic infections develop heart disease 10–30 years after the initial illness, which can lead to heart failure. Digestive complications, including an enlarged esophagus or an enlarged colon, may also occur in up to 21% of people, and up to 10% of people may experience nerve damage.

<i>Trypanosoma</i> Genus of parasitic flagellate protist in the Kinetoplastea class

Trypanosoma is a genus of kinetoplastids, a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Sarcomastigophora. The name is derived from the Greek trypano- (borer) and soma (body) because of their corkscrew-like motion. Most trypanosomes are heteroxenous and most are transmitted via a vector. The majority of species are transmitted by blood-feeding invertebrates, but there are different mechanisms among the varying species. Some, such as Trypanosoma equiperdum, are spread by direct contact. In an invertebrate host they are generally found in the intestine, but normally occupy the bloodstream or an intracellular environment in the vertebrate host.

<span class="mw-page-title-main">Triatominae</span> Subfamily of true bugs

The members of the Triatominae, a subfamily of the Reduviidae, are also known as conenose bugs, kissing bugs, or vampire bugs. Other local names for them used in the Americas include barbeiros, vinchucas, pitos, chipos and chinches. Most of the 130 or more species of this subfamily feed on vertebrate blood; a very few species feed on invertebrates. They are mainly found and widespread in the Americas, with a few species present in Asia and Africa. These bugs usually share shelter with nesting vertebrates, from which they suck blood. In areas where Chagas disease occurs, all triatomine species are potential vectors of the Chagas disease parasite Trypanosoma cruzi, but only those species that are well adapted to living with humans are considered important vectors. Also, proteins released from their bites have been known to induce anaphylaxis in sensitive and sensitized individuals.

Nitrophorins are hemoproteins found in the saliva of blood-feeding insects. Saliva of the blood-sucking bug Rhodnius prolixus contains at least seven homologous nitrophorins, designated NP1 to NP7 in order of their relative abundance in the glands. As isolated, nitrophorins contain nitric oxide (NO) ligated to the ferric heme iron (Fe3+). Histamine, which is released by the host in response to tissue damage, is another nitrophorin ligand. Nitrophorins transport NO to the feeding site. Dilution, binding of histamine and increase in pH (from pH ~5 in salivary gland to pH ~7.4 in the host tissue) facilitate the release of NO into the tissue where it induces vasodilatation.

<i>Triatoma infestans</i> Blood-sucking bug that spreads disease

Triatoma infestans, commonly called winchuka or vinchuca in Argentina, Bolivia, Uruguay and Chile, barbeiro in Brazil, chipo in Venezuela and also known as "kissing bug" or "barber bug" in English, is a blood-sucking bug and the most important vector of Trypanosoma cruzi which can lead to Chagas disease. It is widespread in the Southern Cone countries of South America. This region has joined the control intervention called Southern Cone Initiative managed by the PAHO.

<i>Triatoma</i> Genus of true bugs

Triatoma is a genus of assassin bug in the subfamily Triatominae. The members of Triatoma are blood-sucking insects that can transmit serious diseases, such as Chagas disease. Their saliva may also trigger allergic reactions in sensitive individuals, up to and including severe anaphylactic shock.

<i>Rhodnius</i> Genus of true bugs

Rhodnius is a genus of assassin bugs in the subfamily Triatominae, and is an important vector in the spread of Chagas disease. The Rhodnius species were important models for Sir Vincent Wigglesworth's studies of insect physiology, specifically growth and development.

<i>Panstrongylus geniculatus</i> Species of true bug

Panstrogylus geniculatus is a blood-sucking sylvatic insect noted as a putative vector of minor importance in the transmission of Trypanosoma cruzi to humans; this is a parasite, which causes Chagas disease. The insect is described as sylvatic; subsisting primarily in humid forests, and is also known to inhabit vertebrate nesting places such as those of the armadillo, and is also involved in enzootic transmission of T. cruzi to those species. It has wide distribution throughout 16 Latin American countries.

<span class="mw-page-title-main">Vincent Wigglesworth</span> British entomologist (1899–1994)

Sir Vincent Brian Wigglesworth CBE FRS was a British entomologist who made significant contributions to the field of insect physiology. He established the field in a textbook which was updated in a number of editions.

<i>Trypanosoma cruzi</i> Species of parasitic euglenoids (protozoans)

Trypanosoma cruzi is a species of parasitic euglenoids. Among the protozoa, the trypanosomes characteristically bore tissue in another organism and feed on blood (primarily) and also lymph. This behaviour causes disease or the likelihood of disease that varies with the organism: Chagas disease in humans, dourine and surra in horses, and a brucellosis-like disease in cattle. Parasites need a host body and the haematophagous insect triatomine is the major vector in accord with a mechanism of infection. The triatomine likes the nests of vertebrate animals for shelter, where it bites and sucks blood for food. Individual triatomines infected with protozoa from other contact with animals transmit trypanosomes when the triatomine deposits its faeces on the host's skin surface and then bites. Penetration of the infected faeces is further facilitated by the scratching of the bite area by the human or animal host.

<i>Triatoma nigromaculata</i> Species of true bug

Triatoma nigromaculata is a sylvatic species of insect usually found in hollow trees, in vertebrate nests on trees and occasionally in human dwellings. It usually lives in relatively humid forests at high altitudes on mountain regions and foot hills. As all members of the subfamily Triatominae, T. nigromaculata is a blood-sucking bug and a potential vector of Chagas disease. This species is distributed mainly in Venezuela, but some specimens have also been found in Perú and Colombia (Cauca).

<i>Triatoma brasiliensis</i> Species of true bug

Triatoma brasiliensis is now considered the most important Chagas disease vector in the semiarid areas of northeastern Brazil. T. brasiliensis occurs in 12 Brazilian states, including Maranhão, Piauí, Ceará, Rio Grande do Norte, and Paraíba.

<span class="mw-page-title-main">Disease vector</span> Agent that carries and transmits an infectious pathogen into another living organism

In epidemiology, a disease vector is any living agent that carries and transmits an infectious pathogen to another living organism; agents regarded as vectors are organisms, such as parasites or microbes. The first major discovery of a disease vector came from Ronald Ross in 1897, who discovered the malaria pathogen when he dissected a mosquito.

Trypanosoma rangeli is a species of hemoflagellate excavate parasites of the genus Trypanosoma. Although infecting a variety of mammalian species in a wide geographical area in Central and South America, this parasite is considered non-pathogenic to these hosts. T. rangeli is transmitted by bite of infected triatomine bugs of the Reduviidae family, commonly known as barbeiro, winchuka(vinchuca), chinche, pito ou chupão.

Prothoracicotropic hormone (PTTH) was the first insect hormone to be discovered.The chemical symbol for prothoracicotropic hormone is (C64H102N16O19S2). It was originally described simply as "brain hormone" by early workers such as Stefan Kopeć (1922) and Vincent Wigglesworth (1934), who realized that ligation of the head of immature insects could prevent molting or pupation of the body region excluded from the head if the ligation was performed before a critical age in the lifestage was reached. After a certain point the ligation had no effect and both sections of the insect would molt or pupate. However, implantation of a conspecific brain to a sessile ligated abdomen or an abdomen under diapause would induce molting or pupation. Thus, the brain was originally thought to be the source of the hormone that induces molting in insects.

<i>Triatoma sanguisuga</i> Species of true bug

Triatoma sanguisuga, also known as the Eastern Bloodsucking Conenose, is an insect of the Triatominae subfamily, known as kissing bugs.

<i>Triatoma gerstaeckeri</i> Species of true bug

Triatoma gerstaeckeri is an assassin bug in the genus Triatoma. It is an important vector of Trypanosoma cruzi, the causative agent of Chagas disease. The range of T. gerstaeckeri is from the south-western United States to north-eastern Mexico. T. gerstaeckeri goes through three stages during its paurometabolous life cycle: egg, nymphal instars and adult.

Triatoma indictiva is an arthropod in the assassin bug family of Reduviidae, and is an important vector of Trypanosoma cruzi. T. cruzi is the protozoan that causes Chagas Disease, which affects approximately eight million people a year in the western hemisphere alone. Triatoma indictiva is found in Mexico and throughout the southern United States, including Arizona and Texas.

<i>Triatoma sordida</i> Species of true bug

Triatoma sordida is an assassin bug within the genus Triatoma. This species consists of three subspecies. Also referred to as kissing bugs, T.sordida are most well known for their role as a secondary vector of Chagas Disease. Inhabiting warm, dry climates, T.sordida are widely distributed throughout South America, occupying houses, farming structures, and wild habitats. Pest control is currently focused on insecticide application. However, biological controls utilizing fungi appear promising.

References

  1. Clément, Gilbert; Schaack, Sarah; Pace II, John K.; Brindley, Paul J.; Feschotte, Cédric (2010). "A role for host-parasite interactions in the horizontal transfer of DNA transposons across animal phyla". Nature. 464 (7293): 1347–50. doi:10.1038/nature08939. PMC   3004126 . PMID   20428170.
  2. "Basic Kissing Bugs Facts | Department of Neuroscience". Archived from the original on 2015-07-12. Retrieved 2015-07-12.
  3. C. J .Schofield (2000). "Challenges of Chagas disease vector control in Central America: position paper". World Health Organization.
  4. Wigglesworth, V.B. (1934). "The physiology of ecdysis in Rhodnius prolixus (Hemiptera). II Factors controlling moulting and metamorphosis". Q. J. Microsc. Sci. 77: 191–223.
  5. J. A. V. Butler (1959). Inside the Living Cell. George Allen and Unwin. p. 79.
  6. Fry, Bryan G.; Roelants, Kim; Champagne, Donald E.; Scheib, Holger; Tyndall, Joel D.A.; King, Glenn F.; Nevalainen, Timo J.; Norman, Janette A.; Lewis, Richard J.; Norton, Raymond S.; Renjifo, Camila; de la Vega, Ricardo C. Rodríguez (2009). "The Toxicogenomic Multiverse: Convergent Recruitment of Proteins Into Animal Venoms". Annual Review of Genomics and Human Genetics . Annual Reviews. 10 (1): 483–511. doi: 10.1146/annurev.genom.9.081307.164356 . ISSN   1527-8204. PMID   19640225.
  7. DAVEY, K. G. (1 September 1958). "The Migration of Spermatozoa in the Female of Rhodnius Prolixus Stal". Journal of Experimental Biology. 35 (3): 694–701. doi:10.1242/jeb.35.3.694. ISSN   0022-0949 . Retrieved 26 March 2022.

Further reading