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Evidence of Habitat Structuring Aedes albopictus Populations in Réunion Island  [PDF]
Hélène Delatte ,Céline Toty,Sébastien Boyer,Anthony Bouetard,Fanny Bastien,Didier Fontenille
PLOS Neglected Tropical Diseases , 2013, DOI: 10.1371/journal.pntd.0002111
Abstract: Arbovirus vector dynamics and spread are influenced by climatic, environmental and geographic factors. Major Chikungunya and Dengue fever outbreaks occurring the last 10 years have coincided with the expansion of the mosquito vector Aedes albopictus to nearly all the continents. We characterized the ecological (larval development sites, population dynamics, insemination and daily survival rates) and genetic (diversity, gene flow, population structure) features of two Aedes albopictus populations from distinct environments (rural and urban) on Réunion Island, in the South-West Indian Ocean. Microsatellite analysis suggests population sub-structuring Ae. albopictus populations. Two genetic clusters were identified that were significantly linked to natural versus urban habitats with a mixed population in both areas. Ae. albopictus individuals prefer urban areas for mating and immature development, where hosts and containers that serve as larval development sites are readily available and support high population densities, whereas natural environments appear to serve as reservoirs for the mosquito.
Reproductive Strategies of Aedes albopictus (Diptera: Culicidae) and Implications for the Sterile Insect Technique  [PDF]
Clelia F. Oliva, David Damiens, Marc J. B. Vreysen, Guy Lemperière, Jérémie Gilles
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0078884
Abstract: Male insects are expected to optimize their reproductive strategy according to the availability of sperm or other ejaculatory materials, and to the availability and reproductive status of females. Here, we investigated the reproductive strategy and sperm management of male and virgin female Aedes albopictus, a mosquito vector of chikungunya and dengue viruses. The dynamics of semen transfer to the female bursa inseminalis and spermathecae were observed. Double-mating experiments were conducted to study the effect of time lapsed or an oviposition event between two copulations on the likelihood of a female double-insemination and the use of sperm for egg fertilization; untreated fertile males and radio-sterilised males were used for this purpose. Multiple inseminations and therefore the possibility of sperm competition were limited to matings closely spaced in time. When two males consecutively mated the same female within a 40 min interval, in ca. 15% of the cases did both males sire progeny. When the intervals between the copulations were longer, all progeny over several gonotrophic cycles were offspring of the first male. The mating behavior of males was examined during a rapid sequence of copulations. Male Ae. albopictus were parceling sperm allocation over several matings; however they would also attempt to copulate with females irrespective of the available sperm supply or accessory gland secretion material. During each mating, they transferred large quantities of sperm that was not stored for egg fertilization, and they attempted to copulate with mated females with a low probability of transferring their genes to the next generation. The outcomes of this study provided in addition some essential insights with respect to the sterile insect technique (SIT) as a vector control method.
The Effects of Climate Change and Globalization on Mosquito Vectors: Evidence from Jeju Island, South Korea on the Potential for Asian Tiger Mosquito (Aedes albopictus) Influxes and Survival from Vietnam Rather Than Japan  [PDF]
Su Hyun Lee, Kwang Woo Nam, Ji Yeon Jeong, Seung Jin Yoo, Young-Sang Koh, Seogjae Lee, Sang Taek Heo, Seung-Yong Seong, Keun Hwa Lee
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068512
Abstract: Background Climate change affects the survival and transmission of arthropod vectors as well as the development rates of vector-borne pathogens. Increased international travel is also an important factor in the spread of vector-borne diseases (VBDs) such as dengue, West Nile, yellow fever, chikungunya, and malaria. Dengue is the most important vector-borne viral disease. An estimated 2.5 billion people are at risk of infection in the world and there are approximately 50 million dengue infections and an estimated 500,000 individuals are hospitalized with dengue haemorrhagic fever annually. The Asian tiger mosquito (Aedes albopictus) is one of the vectors of dengue virus, and populations already exist on Jeju Island, South Korea. Currently, colder winter temperatures kill off Asian tiger mosquito populations and there is no evidence of the mosquitos being vectors for the dengue virus in this location. However, dengue virus-bearing mosquito vectors can inflow to Jeju Island from endemic area such as Vietnam by increased international travel, and this mosquito vector's survival during colder winter months will likely occur due to the effects of climate change. Methods and Results In this section, we show the geographical distribution of medically important mosquito vectors such as Ae. albopictus, a vector of both dengue and chikungunya viruses; Culex pipiens, a vector of West Nile virus; and Anopheles sinensis, a vector of Plasmodium vivax, within Jeju Island, South Korea. We found a significant association between the mean temperature, amount of precipitation, and density of mosquitoes. The phylogenetic analyses show that an Ae. albopictus, collected in southern area of Jeju Island, was identical to specimens found in Ho Chi Minh, Vietnam, and not Nagasaki, Japan. Conclusion Our results suggest that mosquito vectors or virus-bearing vectors can transmit from epidemic regions of Southeast Asia to Jeju Island and can survive during colder winter months. Therefore, Jeju Island is no longer safe from vector borne diseases (VBDs) due to the effects of globalization and climate change, and we should immediately monitor regional climate change to identify newly emerging VBDs.
Transcriptomic Evidence for a Dramatic Functional Transition of the Malpighian Tubules after a Blood Meal in the Asian Tiger Mosquito Aedes albopictus  [PDF]
Carlos J. Esquivel,Bryan J. Cassone,Peter M. Piermarini
PLOS Neglected Tropical Diseases , 2014, DOI: 10.1371/journal.pntd.0002929
Abstract: Background The consumption of a vertebrate blood meal by adult female mosquitoes is necessary for their reproduction, but it also presents significant physiological challenges to mosquito osmoregulation and metabolism. The renal (Malpighian) tubules of mosquitoes play critical roles in the initial processing of the blood meal by excreting excess water and salts that are ingested. However, it is unclear how the tubules contribute to the metabolism and excretion of wastes (e.g., heme, ammonia) produced during the digestion of blood. Methodology/Principal Findings Here we used RNA-Seq to examine global changes in transcript expression in the Malpighian tubules of the highly-invasive Asian tiger mosquito Aedes albopictus during the first 24 h after consuming a blood meal. We found progressive, global changes in the transcriptome of the Malpighian tubules isolated from mosquitoes at 3 h, 12 h, and 24 h after a blood meal. Notably, a DAVID functional cluster analysis of the differentially-expressed transcripts revealed 1) a down-regulation of transcripts associated with oxidative metabolism, active transport, and mRNA translation, and 2) an up-regulation of transcripts associated with antioxidants and detoxification, proteolytic activity, amino-acid metabolism, and cytoskeletal dynamics. Conclusions/Significance The results suggest that blood feeding elicits a functional transition of the epithelium from one specializing in active transepithelial fluid secretion (e.g., diuresis) to one specializing in detoxification and metabolic waste excretion. Our findings provide the first insights into the putative roles of mosquito Malpighian tubules in the chronic processing of blood meals.
The first report of Aedes (Stegomyia) albopictus in Haiti
Marquetti Fernández, María del;Jean, Yvan Saint;Fuster Callaba, Carlos A;Somarriba López, Lorenzo;
Memórias do Instituto Oswaldo Cruz , 2012, DOI: 10.1590/S0074-02762012000200020
Abstract: aedes albopictus was found in six of the 10 departments of haiti and in 14 of the 35 communes surveyed. the survey found the larvae of ae. albopictus in 13 different types of containers. used tires and tins were by far the most common breeding sites used by this mosquito species. at the breeding sites, ae. albopictus was associated with other mosquito species, such as aedes aegypti, culex nigripalpus and aedes mediovittatus. the highest proportion of association was with ae. aegypti. this study represents the first report of ae. albopictus in haiti.
Identification and Characterization of Seminal Fluid Proteins in the Asian Tiger Mosquito, Aedes albopictus  [PDF]
Kathryn E. Boes,José M. C. Ribeiro,Alex Wong,Laura C. Harrington,Mariana F. Wolfner,Laura K. Sirot
PLOS Neglected Tropical Diseases , 2014, DOI: 10.1371/journal.pntd.0002946
Abstract: The Asian tiger mosquito (Aedes albopictus) is an important vector for pathogens that affect human health, including the viruses that cause dengue and Chikungunya fevers. It is also one of the world's fastest-spreading invasive species. For these reasons, it is crucial to identify strategies for controlling the reproduction and spread of this mosquito. During mating, seminal fluid proteins (Sfps) are transferred from male mosquitoes to females, and these Sfps modulate female behavior and physiology in ways that influence reproduction. Despite the importance of Sfps on female reproductive behavior in mosquitoes and other insects, the identity of Sfps in Ae. albopictus has not previously been reported. We used transcriptomics and proteomics to identify 198 Sfps in Ae. albopictus. We discuss possible functions of these Sfps in relation to Ae. albopictus reproduction-related biology. We additionally compare the sequences of these Sfps with proteins (including reported Sfps) in several other species, including Ae. aegypti. While only 72 (36.4%) of Ae. albopictus Sfps have putative orthologs in Ae. aegypti, suggesting low conservation of the complement of Sfps in these species, we find no evidence for an elevated rate of evolution or positive selection in the Sfps that are shared between the two Aedes species, suggesting high sequence conservation of those shared Sfps. Our results provide a foundation for future studies to investigate the roles of individual Sfps on feeding and reproduction in this mosquito. Functional analysis of these Sfps could inform strategies for managing the rate of pathogen transmission by Ae. albopictus.
Aedes albopictus in an area of Misiones, Argentina
Schweigmann,Nicolás; Vezzani,Darío; Orellano,Pablo; Kuruc,Jorge; Boffi,Rolando;
Revista de Saúde Pública , 2004, DOI: 10.1590/S0034-89102004000100020
Abstract: until early 1998 the presence of aedes albopictus had never been detected in argentina. during april of the same year, few individuals of this species were recorded in 33 breeding sites found in 25 out of 161 inspected houses in the city of eldorado, province of misiones. the homogeneous spatial distribution of the proliferation foci suggests the existence of a generalized infestation in this locality during the study period.
Aedes albopictus in an area of Misiones, Argentina  [cached]
Schweigmann Nicolás,Vezzani Darío,Orellano Pablo,Kuruc Jorge
Revista de Saúde Pública , 2004,
Abstract: Until early 1998 the presence of Aedes albopictus had never been detected in Argentina. During April of the same year, few individuals of this species were recorded in 33 breeding sites found in 25 out of 161 inspected houses in the city of Eldorado, Province of Misiones. The homogeneous spatial distribution of the proliferation foci suggests the existence of a generalized infestation in this locality during the study period.
Is Switzerland Suitable for the Invasion of Aedes albopictus?  [PDF]
Markus Neteler, Markus Metz, Duccio Rocchini, Annapaola Rizzoli, Eleonora Flacio, Luca Engeler, Valeria Guidi, Peter Lüthy, Mauro Tonolla
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0082090
Abstract: Background Over the last 30 years, the Asian tiger mosquito, Aedes albopictus, has rapidly spread around the world. The European distribution comprises the Mediterranean basin with a first appearance in Switzerland in 2003. Early identification of the most suitable areas in Switzerland allowing progressive invasion by this species is considered crucial to suggest adequate surveillance and control plans. Methodology/Principal Findings We identified the most suitable areas for invasion and establishment of Ae. albopictus in Switzerland. The potential distribution areas linked to the current climatic suitability were assessed using remotely sensed land surface temperature data recorded by the MODIS satellite sensors. Suitable areas for adult survival and overwintering of diapausing eggs were also identified for future climatic conditions, considering two different climate change scenarios (A1B, A2) for the periods 2020–2049 and 2045–2074. At present, the areas around Lake Geneva in western Switzerland provide suitable climatic conditions for Ae. albopictus. In northern Switzerland, parts of the Rhine valley, around Lake Constance, as well as the surroundings of Lake Neuchatel, appear to be suitable for the survival at least of adult Ae. albopictus. However, these areas are characterized by winters currently being too cold for survival and development of diapausing eggs. In southern Switzerland, Ae. albopictus is already well-established, especially in the Canton of Ticino. For the years 2020–2049, the predicted possible spread of the tiger mosquito does not differ significantly from its potential current distribution. However, important expansions are obtained if the period is extended to the years 2045–2074, when Ae. albopictus may invade large new areas. Conclusions/Significance Several parts of Switzerland provide suitable climatic conditions for invasion and establishment of Ae. albopictus. The current distribution and rapid spread in other European countries suggest that the tiger mosquito will colonize new areas in Switzerland in the near future.
Temporal Patterns of Abundance of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) and Mitochondrial DNA Analysis of Ae. albopictus in the Central African Republic  [PDF]
Basile Kamgang,Carine Ngoagouni,Alexandre Manirakiza,Emmanuel Nakouné,Christophe Paupy,Mirdad Kazanji
PLOS Neglected Tropical Diseases , 2013, DOI: 10.1371/journal.pntd.0002590
Abstract: The invasive Asian tiger mosquito Aedes albopictus (Diptera: Culicidae) was first reported in central Africa in 2000, in Cameroon, with the indigenous mosquito species Ae. aegypti (Diptera: Culicidae). Today, this invasive species is present in almost all countries of the region, including the Central African Republic (CAR), where it was first recorded in 2009. As invasive species of mosquitoes can affect the distribution of native species, resulting in new patterns of vectors and concomitant risk for disease, we undertook a comparative study early and late in the wet season in the capital and the main cities of CAR to document infestation and the ecological preferences of the two species. In addition, we determined the probable geographical origin of invasive populations of Ae. albopictus with two mitochondrial DNA genes, COI and ND5. Analysis revealed that Ae. aegypti was more abundant earlier in the wet season and Ae. albopictus in the late wet season. Used tyres were the most heavily colonized productive larval habitats for both species in both seasons. The invasive species Ae. albopictus predominated over the resident species at all sites in which the two species were sympatric. Mitochondrial DNA analysis revealed broad low genetic diversity, confirming recent introduction of Ae. albopictus in CAR. Phylogeographical analysis based on COI polymorphism indicated that the Ae. albopictus haplotype in the CAR population segregated into two lineages, suggesting multiple sources of Ae. albopictus. These data may have important implications for vector control strategies in central Africa.
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