Arthropoda

Taxonomic level: Phylum
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Rhodnius prolixus

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Rhodnius prolixus
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Ellen Dotson
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Rhodnius prolixus is a triatomine vector of the Chagas disease parasite, Trypanosoma cruzi, in South and Central America. Chagas disease is a chronic condition which affects 8 to 10 million people and is the cause of around 20,000 deaths per year.

Triatomine insects release parasites in their faeces immediately after a blood meal. Infection occurs after the human host scratches the bite area, thus transferring parasites into the bite wound.

Short Name: 
rprolixus
Organism taxonomy: 

Aedes albopictus

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Aedes albopictus
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The Asian tiger mosquito, Aedes albopictus, is native to Asia but over the past century it has become established in almost 30 countries in the old and new world. It has the ability to act as a vector for many viral agents including those responsible for Dengue fever, La Crosse encephalitis, Zika virus, and West Nile virus.

Short Name: 
aalbopictus
Organism taxonomy: 

Anopheles albimanus

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Anopheles albimanus
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Range

Anopheles albimanus it is one of the main vectors of malaria in Central America, northern South America and the Caribbean. On the Atlantic coast it is found from Texas to Venezuela, on most of the Caribbean islands and on the Pacific coast, from Mexico to northern Peru.

Habitat

The larval sites used by An. albimanus are characterised across its range as open, sunlit and containing clear water. The species can be found in natural and man-made habitats where these characteristics exist. For example, it occurs in recently planted rice fields, or in older fields with sunlit areas in between the rice plants. The larvae tolerate a wide variation in water chemistry and are able to exploit diverse food sources enabling them to survive in both fresh water (e.g. irrigation channels, small ponds, marshes, slow flowing streams and river margins) and brackish water (e.g. mangrove swamps).

Behaviour

An. albimanus is predominantly exophagic with exophilic resting behaviour, however there is some indication that in the northern reaches of its distribution (Mexico, Central America), this species exhibits a preference for resting indoors after feeding. An. albimanus bites in the evening and during the night. It appears to show a tendency for zoophily, but some reports have indicated anthropophillic activity.

Vectorial capacity

An. albimanus is considered to be a dominant malaria vector species.

This text was modified from Sinka ME et al. (2010) The dominant Anopheles vectors of human malaria in the Americas: occurrence data, distribution maps and bionomic précis Parasites & Vectors 3:72.

Short Name: 
aalbimanus
Organism taxonomy: 

Anopheles aquasalis

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Anopheles aquasalis is a major malaria vector in coastal areas of South and Central America where it breeds preferentially in brackish water. This species is very susceptible to Plasmodium vivax and it has been already incriminated as responsible vector in malaria outbreaks (source).

Short Name: 
aaquasalis
Organism taxonomy: 

Anopheles arabiensis

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Anopheles arabiensis
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Range

Anopheles arabiensis belongs to the An. gambiae species complex, and is one of the most important vectors of malaria in sub-Saharan Africa and surrounding islands.

Habitats

Anopheles arabiensis is considered a species of dry, savannah environments and sparse woodland yet it is known to occur in forested areas, but only where there is a history of recent land disturbance or clearance. Its larval habitats are generally small, temporary, sunlit, clear and shallow fresh water pools, although An. arabiensis is able to utilize a variety of habitats including slow flowing, partially shaded streams and a variety of large and small natural and man-made habitats. It has been found in turbid waters and, on occasion, in brackish habitats. It readily makes use of irrigated rice fields where larval densities are related to the height of the rice, peaking when the plants are still relatively short and then dropping off substantially as the rice plants mature. Such density fluctuations are also reflected in the adult population, which also peak when rice stalks are small and decline as the plants mature. These patterns may be due to a preference for sunlit areas of water with relatively limited emergent vegetation, with densities decreasing as shade from the growing plants increases.

Resting and feeding preferences

An. arabiensis is described as a zoophilic, exophagic and exophilic species. However, it is also known to have a wide range of feeding and resting patterns, depending on geographical location. This behavioural plasticity allows An. arabiensis to adapt quickly to counter indoor residual spraying control showing behavioural avoidance of sprayed surfaces depending on the type of insecticide used. The behavioural variability of An. arabiensis is clearly evident with reports of both anthropophilic and zoophilic behaviour. An east-west behavioural cline has been suggested where populations found in western Africa display higher levels of anthropophily, and preferentially feed and rest indoors, whereas those in the east exhibit greater zoophily and rest outdoors. Overall, however, biting patterns tend to be exophagic. Blood feeding times also vary in frequency but biting generally occurs during the night. Peak evening biting times can begin in the early evening (19:00) or early morning (03:00). This species, demonstrates a predisposition to exophilic (or partial exophilic) behaviour regardless of where it has blood fed or the source of its meal, a behavioural trait considered to be depend on location.

Vectorial capacity

Anopheles arabiensis is considered to be a dominant malaria vector species.

This text was modified from Sinka ME et al. (2010) The dominant Anopheles vectors of human malaria in Africa, Europe and the Middle East: occurrence data, distribution maps and bionomic précis Parasites & Vectors 3:117.

Short Name: 
aarabiensis
Organism taxonomy: 

Anopheles atroparvus

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Anopheles atroparvus
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Range

Anopheles atroparvus belongs to the A. maculipennis species complex. Anopheles atroparvus is distributed in northern and western Europe, Spain, Portugal and northern Italy and was one of the main malaria vectors in Europe.

Habitats

An. atroparvus is described as a species with a preference for brackish larval habitats, however, it has been found in a number of predominantly fresh water habitats as well. For example larvae have been found in canals, ditches, river margins, pools in river beds and rice fields. Larvae have been identified in marshes and ditches/ ground flood pools, pools in river beds, river margins and streams, rock pools, cement tanks, rice fields, wells and ground pools and in small collections of water in used tyres. It prefers relatively cool water, and therefore its range is not considered to overlap with An. labranchiae. Sites may usually be sun exposed and often contain filamentous green algae and other floating submerged vegetation.

Resting and feeding preferences

An. atroparvus is generally considered zoophilic, however, it has also been described as anthropophilic, which perhaps indicates the opportunistic nature of this species. Collection of An. atroparvus has been reported during night catches on horse bait, from indoor resting sites and during day- or night-time catches on humans. There is no clear evidence that identifies this species as preferentially biting indoors or outdoors. The opportunistic nature of its feeding habits and zoophilic preference, however, would suggest it is probably exophagic but that biting location could also depend upon the setting and accessibility of the host. An. atroparvus rests and hibernates in animal sheds and stables.

Vectorial capacity

An. atroparvus is largely unable to transmit tropical strains of Plasmodium falciparum but competent in supporting a European strain.

This text was modified from Sinka ME et al. (2010) The dominant Anopheles vectors of human malaria in Africa, Europe and the Middle East: occurrence data, distribution maps and bionomic précis Parasites & Vectors 3:117.

Short Name: 
aatroparvus
Organism taxonomy: 

Anopheles christyi

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Anopheles christyi is not a malaria vector but is a species closely related to the Anopheles gambiae complex.

Short Name: 
achristyi
Organism taxonomy: 

Anopheles culicifacies A

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Range

Anopheles culicifacies is a complex of five species found in Cambodia, China, Ethiopia, Nepal, Sri Lanka, Thailand, Vietnam, India, Iran and Pakistan, and An, culicifacies A is a malaria vector found in these last three countries.

The Culicifacies Complex includes five species informally named species A, B, C, D and E. The bionomics and ecology of the species within this complex have been largely studied in India and Sri Lanka, and there is a general lack of detailed information from other regions, especially the western areas of its range.

Habitat

The species of the Culicifacies Complex occur in different habitats, ranging from forested areas with perennial streams to deforested riverine ecosystems and irrigated areas. Larval habitats include irrigated canals, stream margins, seepages, borrow pits, hoof marks, rock pools, sandy pools near rice fields, rock quarries, newly dug pits, ponds, domestic wells, tanks and gutters. Immature stages develop in fresh-water habitats but tolerance to moderate salinity has been reported in Oman where larvae have been collected in concrete reservoir tanks containing brackish water. Similarly, species E is able to tolerate variable salinity caused by monsoonal rain in Sri Lanka. It exploits a wide range of aquatic habitats in Sri Lanka, reflecting the significant environmental adaptability of this malaria vector. An. culicifacies C has been observed to greatly outnumber species B in forested areas of Orissa, India whereas species C was found to be most common in deforested areas. In India, species A has been shown to be more abundant in villages with domestic wells, whereas species B was found in higher densities in villages with streams. Species of the Culicifacies Complex are abundant in plains, hilly and mountainous areas up to elevations of 1500m to 2000m in Afghanistan (Kabul region) and the Indian Himalayas.

Resting and feeding preference

Adult biting activity can occur during the first half of the night in cooler months (November-March) and during the second and third quarters of the evening in the warmer months (September-October), although peak biting activity has also been reported as occurring around 23:00 to midnight. Post-feeding behaviour of the species showed a higher tendency for resting indoors, mainly in cattle sheds, but outdoor resting has also been reported. As members of the Culicifacies Complex exhibit distinctly different behaviour, a more thorough study of the bionomics of each species must be undertaken to specifically and efficiently target control efforts against those species involved in malaria transmission.

Vectorial capacity

Four species of the complex (A, C, D, E) are reportedly malaria vectors in India where it is estimated they are responsible for transmitting 60-65% of all cases of malaria in peri-urban and urban environments. Anopheles culicifacies E, due to its high anthropophilic and endophilic behaviour, is the most important and efficient vector of Plasmodium falciparum and P. vivax in southern India and Sri Lanka. Species A, C and D appear to be mainly zoophilic. Therefore, these three species generally play very minor roles in malaria transmission although species C was found to be responsible for local malaria transmission in deforested riverine areas of central India. Due to its highly zoophilic behaviour, species B is considered to be a poor or non-vector.

This text was modified from Sinka ME et al. (2011) The dominant Anopheles vectors of human malaria in Asia-Pacific region: occurrence data, distribution maps and bionomic précis Parasites & Vectors 4:89.

Short Name: 
aculicifaciesa
Organism taxonomy: 

Anopheles darlingi

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Range

Anopheles darlingi is one of the most important vectors of malaria in the Neotropics (Mexico, Central and South America), with populations from southern Mexico to Argentina.

Habitat

An. darlingi is a riverine mosquito, generally confined to rural, lowland forested locations. Deforestation and other human driven environmental change can create habitats which are favourable, with An. darlingi reportedly found at higher densities in areas with limited forest cover than in those predominated by forest. The larval habitats of An. darlingi can be characterized as natural water bodies such as lagoons, lakes and particularly slow flowing streams or rivers with shaded, clear water associated with submersed vegetation such as bamboo roots from overhanging spiny bamboo. Larvae are encountered most frequently in patches of floating debris along river margins. There are examples of larvae being found in uncharacteristic locations, such as in slightly brackish water; in low numbers in turbid, polluted water (brick pits); and in abandoned gold mine dugouts in southern Venezuela, further suggesting a level of adaptability to areas altered by humans. Moreover, An. darlingi appears to be adapting to higher altitude habitats with specimens recently collected at altitudes above 800m in Venezuela, close to the Brazilian border (Roraima).

Resting and feeding preferences

An. darlingi tends to rest outdoors regardless of where it has taken its blood meal. Adults will bite throughout the night and the degree of endo- and exophagy of this species varies from one place to another as does its host preference. It has been suggested that the biting pattern of An. darlingi may represent an adaptation to human behaviour, for example, the all night activity of An. darlingi in the gold mining areas of southern Venezuela may be a response to the all night activity of the miners. Furthermore, a number of studies that report exophagy in this species may be linked to sites where indoor insecticide spraying is or has recently been used for vector control.

Vectorial capacity

An. darlingi is considered to be one of the most efficient malaria vectors in the Neotropical region.

Short Name: 
adarlingi
Organism taxonomy: 

Anopheles epiroticus

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The Anopheles sundaicus complex includes Anopheles epiroticus (formerly A. sundaicus A), which is a malaria vector located in Cambodia, peninsular Malaysia, Sarawak, Thailand and Vietnam.

Short Name: 
aepiroticus
Organism taxonomy: 

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