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1.
J Am Mosq Control Assoc ; 37(2): 87-89, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34184042

RESUMO

In Mexico, Aedes podographicus is one of the most common species within the subgenus Protomacleaya of Aedes. This species has been collected in 12 states close to the coastal regions; however, few records confirm the presence of Ae. podographicus inland. During a mosquito-survey using ovitraps in the state of Nuevo León, Mexico, Ae. podographicus was collected in association with Ae. albopictus and Culex quinquefasciatus. This is the first record of the presence of Ae. podographicus in Nuevo León. With the addition of Ae. podographicus to the mosquito fauna of Nuevo León, there are currently 66 species in the state, 19 within the genus Aedes and 6 within the subgenus Protomacleaya, the genus Aedes being the group with the major number of species in Nuevo León. Specimens collected during this study were deposited in the collection of insects and mites of medical importance of the Laboratory of Medical Entomology of the Autonomous University of Nuevo León, Mexico.


Assuntos
Aedes , Culex , Ochlerotatus , Animais , México
2.
J Am Mosq Control Assoc ; 37(2): 101-105, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34184044

RESUMO

The response of mosquitoes to bushfire is poorly understood. During the 2019-20 summer, many regions of Australia were impacted by devastating bushfires. An area of estuarine and brackish-water wetlands alongside the Georges River, Sydney, New South Wales, was burned in January 2020. Mosquito populations within the area were monitored as part of the local authority's mosquito management program, providing a unique opportunity to record the response of key mosquitoes of pest and public health concern to bushfire. Ground pools within a tidally influenced swamp oak forest dominated by Casuarina glauca and associated wetlands dominated by Phragmites australis and Bolboschoenus spp. had been identified as suitable habitat for a range of mosquitoes, including Aedes alternans, Ae. vigilax, and Verrallina funerea. Surveys of immature stages of mosquitoes within recently burned habitats inundated by tides demonstrated that mosquito eggs survived the direct and indirect impacts of fire and immature stages successfully completed development as reflected in concomitant changes in adult mosquito populations following the bushfire. This unique observation has implications for mosquito management following bushfire in Australia and internationally.


Assuntos
Aedes , Ochlerotatus , Animais , Austrália , Ecossistema , Áreas Alagadas
3.
J Med Entomol ; 58(1): 222-240, 2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33432351

RESUMO

Given that accurately identifying pathogen vectors is vital for designing efficient mosquito control programs based on the proper surveillance of the epidemiologically important species, it has been suggested the complementary use of independently evolving genes and morphometric traits as a reliable approach for the characterization and delimitation of related species. Hence, we examined the spatial distribution of COI mtDNA and ITS2 rDNA variation from the historical perspective of Ochlerotatus caspius (Pallas, 1771) and O. dorsalis (Meigen, 1830), while simultaneously testing the utility of the two markers in integrative species delimitation when combined with phenotypic character analyses of larvae and adults. Despite the striking difference in haplotype diversity (high in COI mtDNA, low in ITS2 rDNA), no evident phylogeographic structure was apparent in the Palearctic O. caspius. The Holarctic O. dorsalis species was subdivided into two highly distinctive COI mtDNA phylogroups which corresponded to the Nearctic and Palearctic regions. Strong support for the independence of the two allopatric evolutionary lineages suggested that geographical barrier and climatic changes during Pleistocene caused vicariance of the ancestral range. COI mtDNA reliably distinguished O. caspius and O. dorsalis, while ITS2 rDNA yet again lacked the proper resolution for solving this problem. An integrative approach based on the larval and adult morphological traits have varying taxonomic applications due to their differential diagnostic values. Thus, by the implementation of an integrative taxonomic approach, we successfully detected species borders between the two epidemiologically relevant species and uncovered the presence of cryptic diversity within O. dorsalis.


Assuntos
Variação Genética , Ochlerotatus/classificação , Ochlerotatus/genética , Animais , DNA Espaçador Ribossômico/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Feminino , Marcadores Genéticos/genética , Haplótipos , Proteínas de Insetos/análise , Larva/classificação , Larva/enzimologia , Larva/genética , Masculino , Ochlerotatus/enzimologia , Filogeografia , Especificidade da Espécie
4.
J Med Entomol ; 58(2): 717-729, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33225354

RESUMO

Aedes scapularis (Rondani), a widespread neotropical vector mosquito species, has been included in the mosquito fauna of Florida on the basis of just three larval specimens that were collected in the middle Florida Keys in 1945. Here, we report numerous recent collections of immature and adult Ae. scapularis from multiple locations in two counties of southern Florida. These specimens represent the first records of Ae. scapularis from mainland Florida and the first records of the species in the state since the initial detection of the species 75 yr ago. Collections of both larvae and adults across several years indicate that Ae. scapularis is now established in Broward and Miami-Dade Counties. These contemporary records of this species in Florida may represent novel dispersal and subsequent establishment events from populations outside the United States or a recent reemergence of undetected endemic populations. To confirm morphological identification of Ae. scapularis specimens from Florida, the DNA barcoding region of the cytochrome c oxidase subunit I gene (COI) was sequenced and compared to all other Ochlerotatus Group species from the United States, specifically Aedes condolescens Dyar and Knab (Diptera: Culicidae), Aedes infirmatus Dyar and Knab (Diptera: Culicidae), Aedes thelcter Dyar (Diptera: Culicidae), Aedes tortilis (Theobald) (Diptera: Culicidae), and Aedes trivittatus (Coquillett) (Diptera: Culicidae). Molecular assays and sequencing confirm morphological identification of Ae. scapularis specimens. Maximum likelihood phylogenetic analysis of COI and ITS2 sequences place Florida Ae. scapularis in a distinct clade, but was unable to produce distinct clades for Florida specimens of Ae. condolescens and Ae. tortilis.


Assuntos
Aedes , Distribuição Animal , Ochlerotatus , Aedes/classificação , Aedes/genética , Animais , Classificação , Culicidae/classificação , Culicidae/genética , Código de Barras de DNA Taxonômico , DNA Intergênico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Florida , Genes de Insetos , Espécies Introduzidas , Larva/classificação , Larva/genética , Mosquitos Vetores/classificação , Mosquitos Vetores/genética , Ochlerotatus/classificação , Ochlerotatus/genética , Filogenia
5.
Parasit Vectors ; 13(1): 413, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32787904

RESUMO

BACKGROUND: There has been no evidence of transmission of mosquito-borne arboviruses of equine or human health concern to date in the UK. However, in recent years there have been a number of outbreaks of viral diseases spread by vectors in Europe. These events, in conjunction with increasing rates of globalisation and climate change, have led to concern over the future risk of mosquito-borne viral disease outbreaks in northern Europe and have highlighted the importance of being prepared for potential disease outbreaks. Here we assess several UK mosquito species for their potential to transmit arboviruses important for both equine and human health, as measured by the presence of viral RNA in saliva at different time points after taking an infective blood meal. RESULTS: The following wild-caught British mosquitoes were evaluated for their potential as vectors of zoonotic equine arboviruses: Ochlerotatus detritus for Venezuelan equine encephalitis virus (VEEV) and Ross River virus (RRV), and Culiseta annulata and Culex pipiens for Japanese encephalitis virus (JEV). Production of RNA in saliva was demonstrated at varying efficiencies for all mosquito-virus pairs. Ochlerotatus detritus was more permissive for production of RRV RNA in saliva than VEEV RNA. For RRV, 27.3% of mosquitoes expectorated viral RNA at 7 days post-infection when incubated at 21 °C and 50% at 24 °C. Strikingly, 72% of Cx. pipiens produced JEV RNA in saliva after 21 days at 18 °C. For some mosquito-virus pairs, infection and salivary RNA titres reduced over time, suggesting unstable infection dynamics. CONCLUSIONS: This study adds to the number of Palaearctic mosquito species that demonstrate expectoration of viral RNA, for arboviruses of importance to human and equine health. This work adds to evidence that native mosquito species should be investigated further for their potential to vector zoonotic mosquito-borne arboviral disease of equines in northern Europe. The evidence that Cx. pipiens is potentially an efficient laboratory vector of JEV at temperatures as low as 18 °C warrants further investigation, as this mosquito is abundant in cooler regions of Europe and is considered an important vector for West Nile Virus, which has a comparable transmission ecology.


Assuntos
Infecções por Arbovirus/veterinária , Arbovírus/isolamento & purificação , Mosquitos Vetores/virologia , Aedes/virologia , Animais , Infecções por Arbovirus/transmissão , Culex/virologia , Vírus da Encefalite Japonesa (Espécie)/isolamento & purificação , Vírus da Encefalite Equina Venezuelana/isolamento & purificação , Doenças dos Cavalos/transmissão , Doenças dos Cavalos/virologia , Cavalos , Humanos , Ochlerotatus/virologia , Patologia Molecular , RNA Viral/análise , Vírus do Rio Ross/isolamento & purificação , Saliva/virologia , Reino Unido/epidemiologia , Febre do Nilo Ocidental/transmissão , Zoonoses/transmissão , Zoonoses/virologia
6.
Parasitol Res ; 119(9): 2765-2774, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32671542

RESUMO

Before the background of increasingly frequent outbreaks and cases of mosquito-borne diseases in various European countries, Germany recently realised the necessity of updating decade-old data on the occurrence and spatiotemporal distribution of culicid species. Starting in 2011, a mosquito monitoring programme was therefore launched with adult and immature mosquito stages being collected at numerous sites all over Germany both actively by trapping, netting, aspirating and dipping, and passively by the citizen science project 'Mueckenatlas'. Until the end of 2019, about 516,000 mosquito specimens were analysed, with 52 (probably 53) species belonging to seven genera found, including several species not reported for decades due to being extremely rare (Aedes refiki, Anopheles algeriensis, Culex martinii) or local (Culiseta alaskaensis, Cs. glaphyroptera, Cs. ochroptera). In addition to 43 (probably 44 including Cs. subochrea) out of 46 species previously described for Germany, nine species were collected that had never been documented before. These consisted of five species recently established (Ae. albopictus, Ae. japonicus, Ae. koreicus, An. petragnani, Cs. longiareolata), three species probably introduced on one single occasion only and not established (Ae. aegypti, Ae. berlandi, Ae. pulcritarsis), and a newly described cryptic species of the Anopheles maculipennis complex (An. daciae) that had probably always been present but not been differentiated from its siblings. Two species formerly listed for Germany could not be documented (Ae. cyprius, Ae. nigrinus), while presence is likely for another species (Cs. subochrea), which could not be demonstrated in the monitoring programme as it can neither morphologically nor genetically be reliably distinguished from a closely related species (Cs. annulata) in the female sex. While Cs. annulata males were collected in the present programme, this was not the case with Cs. subochrea. In summary, although some species regarded endemic could not be found during the last 9 years, the number of culicid species that must be considered firmly established in Germany has increased to 51 (assuming Cs. subochrea and Ae. nigrinus are still present) due to several newly emerged ones but also to one species (Ae. cyprius) that must be considered extinct after almost a century without documentation. Most likely, introduction and establishment of the new species are a consequence of globalisation and climate warming, as three of them are native to Asia (Ae. albopictus, Ae. japonicus, Ae. koreicus) and three (Ae. albopictus, An. petragnani, Cs. longiareolata) are relatively thermophilic. Another thermophilic species, Uranotaenia unguiculata, which had been described for southwestern Germany in 1994 and had since been found only at the very site of its first detection, was recently documented at additional localities in the northeastern part of the country. As several mosquito species found in Germany are serious pests or potential vectors of disease agents and should be kept under permanent observation or even be controlled immediately on emergence, the German mosquito monitoring programme has recently been institutionalised and perpetuated.


Assuntos
Aedes/classificação , Anopheles/classificação , Culex/classificação , Monitoramento Ambiental/métodos , Mosquitos Vetores/classificação , Ochlerotatus/classificação , Animais , Ásia , Clima , Europa (Continente) , Feminino , Alemanha , Espécies Introduzidas , Masculino
7.
Emerg Microbes Infect ; 9(1): 903-912, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32302268

RESUMO

Jamestown Canyon virus (JCV) is a neuroinvasive arbovirus that is found throughout North America and increasingly recognized as a public health concern. From 2004 to 2012, an average of 1.7 confirmed cases were reported annually in the United States, whereas from 2013 to 2018 this figure increased over seventeen-fold to 29.2 cases per year. The rising number of reported human infections highlights the need for better understanding of the clinical manifestations and epidemiology of JCV. Here, we describe nine patients diagnosed with neuroinvasive JCV infection in Massachusetts from 2013, the year of the first reported case in the state, to 2017. Because current diagnostic testing relies on serology, which is complicated by cross-reactivity with related orthobunyaviruses and can be negative in immunosuppressed patients, we developed and evaluated an RT-qPCR assay for detection of JCV RNA. We tested this on the available archived serum from two patients, but did not detect viral RNA. JCV is transmitted by multiple mosquito species and its primary vector in Massachusetts is unknown, so we additionally applied the RT-qPCR assay and confirmatory RNA sequencing to assess JCV prevalence in a vector candidate, Ochlerotatus canadensis. We identified JCV in 0.6% of mosquito pools, a similar prevalence to neighboring Connecticut. We assembled the first Massachusetts JCV genome directly from a mosquito sample, finding high identity to JCV isolates collected over a 60-year period. Further studies are needed to reconcile the low vector prevalence and low rate of viral evolutionary change with the increasing number of reported cases.


Assuntos
Culicidae/virologia , Vírus da Encefalite da Califórnia , Encefalite/virologia , Meningite/virologia , Ochlerotatus/virologia , Adulto , Idoso , Animais , Vetores de Doenças , Encefalite/diagnóstico , Vírus da Encefalite da Califórnia/genética , Vírus da Encefalite da Califórnia/imunologia , Vírus da Encefalite da Califórnia/isolamento & purificação , Feminino , Genoma Viral , Humanos , Masculino , Massachusetts/epidemiologia , Meningite/diagnóstico , Pessoa de Meia-Idade , Mosquitos Vetores/virologia , Filogenia , Prevalência , RNA Viral
8.
Parasitology ; 147(4): 441-447, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31965951

RESUMO

Factors such as the particular combination of parasite-mosquito species, their co-evolutionary history and the host's parasite load greatly affect parasite transmission. However, the importance of these factors in the epidemiology of mosquito-borne parasites, such as avian malaria parasites, is largely unknown. Here, we assessed the competence of two mosquito species [Culex pipiens and Aedes (Ochlerotatus) caspius], for the transmission of four avian Plasmodium lineages (Plasmodium relictum SGS1 and GRW11 and Plasmodium cathemerium-related lineages COLL1 and PADOM01) naturally infecting wild house sparrows. We assessed the effects of parasite identity and parasite load on Plasmodium transmission risk through its effects on the transmission rate and mosquito survival. We found that Cx. pipiens was able to transmit the four Plasmodium lineages, while Ae. caspius was unable to transmit any of them. However, Cx. pipiens mosquitoes fed on birds infected by P. relictum showed a lower survival and transmission rate than those fed on birds infected by parasites related to P. cathemerium. Non-significant associations were found with the host-parasite load. Our results confirm the existence of inter- and intra-specific differences in the ability of Plasmodium lineages to develop in mosquito species and their effects on the survival of mosquitoes that result in important differences in the transmission risk of the different avian malaria parasite lineages studied.


Assuntos
Culex/parasitologia , Malária Aviária/transmissão , Mosquitos Vetores/parasitologia , Ochlerotatus/parasitologia , Plasmodium/fisiologia , Pardais , Aedes/parasitologia , Animais , Feminino , Masculino , Plasmodium/classificação , Plasmodium/genética , Espanha , Especificidade da Espécie
9.
Med Vet Entomol ; 34(2): 225-228, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31414514

RESUMO

Mosquito feeding preferences determine host-vector contact rates and represent a key factor in the transmission of vector-borne pathogens. The semiochemical compounds of which vertebrate odours are composed probably play a role in mosquito host choice. Birds spread secretions from uropygial gland over their feathers to protect their plumage, comprising behaviour that may in turn affect odour profiles. Although uropygial secretions are expected to modify the attractiveness of birds to mosquitoes, contradictory findings have been reported. Mosquito species differ in their feeding preferences, with some species feeding mainly on birds (ornithophilic species) and others on mammals (mammophilic species). Consequently, it is possible that ornithophilic and mammophilic species differ in their response to uropygial gland secretions. Using a dual-choice olfactometer, the present study tests this hypothesis by comparing the behavioural response to uropygial gland secretions from juvenile male and female house sparrows (Passer domesticus) in the ornithophilic Culex pipiens and the mammophilic Aedes (Ochlerotatus) caspius mosquitoes. No differences were found in the response of either mosquito species to the uropygial gland secretions. Therefore, the preference of ornithophilic mosquitoes for avian hosts is apparently not explained by a greater attraction of mosquitoes to the uropygial gland secretion odour when presented in combination with a CO2 -enriched airflow.


Assuntos
Aedes/fisiologia , Quimiotaxia , Culex/fisiologia , Glândulas Exócrinas/metabolismo , Odorantes/análise , Pardais , Animais , Feminino , Masculino , Ochlerotatus/fisiologia
10.
Med Vet Entomol ; 34(1): 10-16, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31566765

RESUMO

A population of Aedes (Stegomyia) albopictus (Skuse) (Diptera: Culicidae), a vector of chikungunya, dengue, yellow fever, and Zika and West Nile viruses, has been detected in Windsor, Ontario, Canada from 2016 onwards. Here, we describe its seasonal distribution, as well as the various aquatic habitats from which this species was collected and its larval co-habitation. We collected immatures from tires, treeholes, extruded polystyrene foam containers, discarded plastic cups, old recycling bins and oviposition traps. Aedes albopictus larvae were collected with Aedes japonicus (Theobald), Anopheles punctipennis (Say), Culex pipiens Linnaeus, Ochlerotatus hendersoni (Cockerell), Ochlerotatus triseriatus (Say) and Orthopodomyia signifera (Coquillett). Adult female and male specimens were collected from Biogents sentinel traps (Biogents AG, Regensburg, Germany), as well as Centers for Disease Control and Prevention miniature light traps (CDC, Atlanta, GA, U.S.A.), and also as they alighted on the investigators. Peak adult collections occurred in September during epidemiological week 37. We also collected Aedes (Stegomyia) aegypti (Linnaeus), a new record for Canada, in 2016 and from two new collection sites in 2017. The 2017 collections were 3.5 km north and 19.4 km south of the index site. The present study adds to the increasing number of studies reporting range expansions of these mosquito species.


Assuntos
Aedes , Distribuição Animal , Aedes/crescimento & desenvolvimento , Animais , Anopheles , Culex , Ecossistema , Feminino , Larva/crescimento & desenvolvimento , Masculino , Ochlerotatus , Ontário
11.
J Am Mosq Control Assoc ; 35(2): 135-136, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31442125

RESUMO

Aedes albifasciatus is one of the most widely distributed mosquitoes in the Southern Cone of South America, and a known vector of western equine encephalomyelitus. Despite its wide range of distribution and relatively large abundance over its distribution, little is known about the ecological interactions in adults. In this contribution we record the first predation record of the damselbug Nabis paranensis (Nabidae) over an adult male of A. albifasciatus. The interaction record is analyzed and discussed.


Assuntos
Cadeia Alimentar , Hemípteros/fisiologia , Ochlerotatus , Comportamento Predatório , Aedes , Animais , Argentina , Masculino
12.
J Am Mosq Control Assoc ; 35(2): 91-96, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31442131

RESUMO

The introduction of Zika virus to the USA in 2015 engendered heightened interest in its known vectors. Aedes aegypti is the primary vector, with Ae. albopictus considered a potential secondary vector, together with several other possible marginal vectors. In Delaware, Ae. aegypti has been collected rarely, but no breeding populations were detected during past intensive statewide surveillance efforts. However, there is an abundance of Ae. albopictus statewide. Both species are container breeders and are peri-domestic-increasing the risk for virus transmission to humans. From July through September 2017, Delaware Mosquito Control conducted surveillance in 16 container-breeding hot spots to search for Ae. aegypti, and also ascertain the virus-positive pool rates of Ae. albopictus and Ae. triseriatus for West Nile virus (WNV) and Zika virus (ZIKV). The survey concluded that there were no known breeding populations of Ae. aegypti in Delaware, and no WNV- or ZIKV-positive pools were detected among pools of mosquitoes of the aforementioned species.


Assuntos
Aedes/fisiologia , Aedes/virologia , Distribuição Animal , Ochlerotatus/fisiologia , Ochlerotatus/virologia , Vírus do Nilo Ocidental/isolamento & purificação , Zika virus/isolamento & purificação , Aedes/crescimento & desenvolvimento , Animais , Delaware , Feminino , Larva/fisiologia , Larva/virologia , Masculino , Especificidade da Espécie
13.
J Am Mosq Control Assoc ; 35(1): 71-74, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-31442180

RESUMO

In 2017, the southeastern USA and Caribbean endured an extremely active year for tropical storm and hurricane activity. On September 10, 2017, Hurricane Irma made a 2nd landfall in Florida, striking Collier County-including Naples and Marco Island, FL. Areas affected by Hurricane Irma are abundant in salt-marsh and mangrove swamps, prime habitats for the black salt-marsh mosquito, Aedes taeniorhynchus. Using both human landing rate and Biogents BG-Counter trap data, here we report the year-to-year fluctuations in population density of Ae. taeniorhynchus. In 2017, Collier County experienced a population explosion of Ae. taeniorhynchus, with daily landing rates reaching as high as 150 adult females/2-min period. The following year a dramatic population crash of Ae. taeniorhynchus was observed, representing some of the lowest Ae. taeniorhynchus numbers ever recorded in Collier County. Analysis of human landing rate and trap data following major hurricane strikes, including Hurricane Irma (2017) and Hurricane Wilma (2005), have revealed severe reductions in Ae. taeniorhynchus populations. Because Ae. taeniorhynchus accounts for a large majority of adulticiding missions in the state of Florida, an enhanced understanding of the factors contributing to Ae. taeniorhynchus population dynamics may allow for improved operational planning and decision-making.


Assuntos
Aedes , Tempestades Ciclônicas , Áreas Alagadas , Animais , Feminino , Florida , Ochlerotatus , Densidade Demográfica
14.
J Med Entomol ; 56(5): 1290-1295, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31095691

RESUMO

Aedes vigilax (Skuse) is a pest and vector species associated with coastal wetlands and the abundance of this mosquito has been identified as contributing to increased risk of mosquito-borne disease outbreaks. As urban development continues to encroach on these coastal wetlands, pest and public health impacts are becoming of increasing concern and in the absence of broadscale mosquito control. Urban planners are looking to buffer zones and other land use planning options to minimize contact between mosquitoes and humans but gaps in the understanding of dispersal ranges of mosquitoes hamper the adoption of these strategies. A mark-release-recapture experiment was conducted to measure the dispersal of this mosquito from an urban estuarine wetland in Sydney, Australia. An estimated total of over 150,000 wild caught female mosquitoes were marked with fluorescent dust and then released. A network of 38 traps was then operated for 5 d within an area of 28 km2. A total of 280 marked mosquitoes was recaptured, representing less than 1% of the estimate 250,000 marked mosquitoes released. Marked mosquitoes were recaptured up to 3 km from the release point, providing an insight into the dispersal range of these mosquitoes. The mean distance traveled by marked mosquitoes was 0.83 km, a result reflecting the greater proportion of marked mosquitoes recaptured near release point. The findings of this study indicate that effective buffer zones between estuarine wetlands and high-density urban developments would be an impractical approach to minimizing pest and public health impacts associated with this mosquito.


Assuntos
Distribuição Animal , Ochlerotatus/fisiologia , Aedes/fisiologia , Animais , Cidades , Estuários , Feminino , New South Wales , Áreas Alagadas
15.
J Med Entomol ; 56(5): 1377-1383, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31121045

RESUMO

The present study aimed to update the list of Aedes mosquito species occurring in Tunisia and to test the vector competence of Aedes (Ochlerotatus) caspius (Pallas) and Ae. (Ochlerotatus) detritus (Haliday), the locally most abundant and widespread species, to transmit Zika virus (ZIKV). In 2017-2018, mosquito larvae were collected from 39 different larval habitats in seven bioclimatic zones of Tunisia. The salinity and pH of each breeding site were measured. The survey revealed the presence of 10 Aedes species in Tunisia: Ae. (Stegomyia) albopictus (Skuse), Ae. (Ochlerotatus) berlandi (Séguy), Ae. caspius, Ae. detritus, Ae. (Finlaya) echinus (Edwards), Ae. (Finlaya) geniculatus (Olivier), Ae. (Acartomyia) mariae (Sergent and Sergent), Ae. (Ochlerotatus) pulcritarsis (Rondani), Ae. (Aedimorphus) vexans (Meigen), and Ae. (Fredwardsius) vittatus (Bigot). Of these 10 species, Ae. caspius and Ae. detritus were the most abundant in Tunisia. Aedes detritus and Ae. caspius larvae were reared until the imago stage under insectary conditions to test autogeny. The study showed that Ae. detritus is autogenous and stenogamous and Ae. caspius, anautogenous and eurygamous. Finally, the collected strains of these two species were experimentally infected with the Asian genotype of ZIKV, originally isolated from a patient in April 2014 in New Caledonia, to test their vector competence. Neither of these species was able to transmit ZIKV at 7 and 14 d postexposure. Further investigations are needed to test the competence of other Tunisian mosquito species that may be associated with ZIKV transmission.


Assuntos
Mosquitos Vetores/parasitologia , Ochlerotatus/parasitologia , Infecção por Zika virus/transmissão , Zika virus/fisiologia , Aedes/crescimento & desenvolvimento , Aedes/parasitologia , Animais , Feminino , Larva , Ochlerotatus/crescimento & desenvolvimento , Tunísia
16.
Parasit Vectors ; 12(1): 87, 2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30867014

RESUMO

BACKGROUND: The transmission of mosquito-borne pathogens is strongly influenced by the contact rates between mosquitoes and susceptible hosts. The biting rates of mosquitoes depend on different factors including the mosquito species and host-related traits (i.e. odour, heat and behaviour). However, host characteristics potentially affecting intraspecific differences in the biting rate of mosquitoes are poorly known. Here, we assessed the impact of three host-related traits on the biting rate of two mosquito species with different feeding preferences: the ornithophilic Culex pipiens and the mammophilic Ochlerotatus (Aedes) caspius. Seventy-two jackdaws Corvus monedula and 101 house sparrows Passer domesticus were individually exposed to mosquito bites to test the effect of host sex, body mass and infection status by the avian malaria parasite Plasmodium on biting rates. RESULTS: Ochlerotatus caspius showed significantly higher biting rates than Cx. pipiens on jackdaws, but non-significant differences were found on house sparrows. In addition, more Oc. caspius fed on female than on male jackdaws, while no differences were found for Cx. pipiens. The biting rate of mosquitoes on house sparrows increased through the year. The bird infection status and body mass of both avian hosts were not related to the biting rate of both mosquito species. CONCLUSIONS: Host sex was the only host-related trait potentially affecting the biting rate of mosquitoes, although its effect may differ between mosquito and host species.


Assuntos
Doenças das Aves/transmissão , Culex/parasitologia , Malária/veterinária , Mosquitos Vetores/parasitologia , Ochlerotatus/parasitologia , Plasmodium/fisiologia , Animais , Comportamento Animal , Doenças das Aves/parasitologia , Corvos , Comportamento Alimentar , Feminino , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Mordeduras e Picadas de Insetos/veterinária , Malária/parasitologia , Malária/transmissão , Masculino , Fenótipo , Fatores Sexuais , Pardais
17.
Parasit Vectors ; 11(1): 303, 2018 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-29769098

RESUMO

BACKGROUND: Gene flow restrictions between populations of Aedes albifasciatus, the vector of Western equine encephalitis and Dirophilaria immitis, have been described in the central region of Argentina. Genetic and eco-physiological variations usually result in local forms reflecting the climatic regions. Mosquito wings and their different parts have ecological functions in flight and communication. Therefore, wing shape could be considered an aspect of sexual dimorphism, and its eco-physiological responses can be expressed as morphological changes induced by the environment. METHODS: To compare the geographical and sexual variations with respect to wing shape and size in two Ae. albifasciatus populations from contrasting climates of Argentina (temperate: Buenos Aires, and the arid steppe of Patagonia: Sarmiento), the wings of adults reared in thermal trays at different constant temperatures (10-29 °C) were analyzed. RESULTS: The wing size of Ae. albifasciatus showed inverse linear relationships with the rearing thermal condition and higher slope for Buenos Aires. In the cool range (10-17 °C), geographical size variations responded to the converse Bergmann's rule, where Buenos Aires individuals were larger than those from Sarmiento. Sexual shape dimorphism occurred in both populations while geographical variation in shape was observed in both sexes. CONCLUSIONS: Buenos Aires individuals showed greater response sensitivity with respect to the size-temperature relation than those from Sarmiento. The converse Bergmann's rule in size variation could be due to a higher development rate in Sarmiento to produce more cohorts in the limited favorable season. The shape could be more relevant with respect to the size in the study of population structures due to the size being more liable to vary due to changes in the environment. The geographical variations with respect to morphology could be favored by the isolation between populations and adaptations to the environmental conditions. Our results demonstrate that the shape and size of wing provide useful phenotypic information for studies related to sexual and environmental adaptations.


Assuntos
Aedes/anatomia & histologia , Clima , Temperatura , Asas de Animais/anatomia & histologia , Aedes/genética , Aedes/fisiologia , Animais , Argentina , Fluxo Gênico , Larva/fisiologia , Mosquitos Vetores/anatomia & histologia , Mosquitos Vetores/fisiologia , Ochlerotatus/anatomia & histologia , Ochlerotatus/genética , Ochlerotatus/fisiologia , Densidade Demográfica , Estações do Ano , Caracteres Sexuais
18.
Sci Rep ; 8(1): 2599, 2018 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-29422507

RESUMO

Mosquito community composition plays a central role in the transmission of zoonotic vector-borne pathogens. We evaluated how the mosquito community affects the seroprevalence of West Nile virus (WNV) in house sparrows along an urbanisation gradient in an area with the endemic circulation of this virus. We sampled 2544 birds and 340829 mosquitoes in 45 localities, analysed in 15 groups, each containing one urban, one rural and one natural area. WNV seroprevalence was evaluated using an epitope-blocking ELISA kit and a micro virus-neutralization test (VNT). The presence of WNV antibodies was confirmed in 1.96% and 0.67% of birds by ELISA and VNT, respectively. The VNT-seropositive birds were captured in rural and natural areas, but not in urban areas. Human population density was zero in all the localities where VNT-positive birds were captured, which potentially explains the low incidence of human WNV cases in the area. The prevalence of neutralizing antibodies against WNV was positively correlated with the abundance of the ornithophilic Culex perexiguus but negatively associated with the abundance of the mammophilic Ochlerotatus caspius and Anopheles atroparvus. These results suggest that the enzootic circulation of WNV in Spain occurs in areas with larger populations of Cx. perexiguus and low human population densities.


Assuntos
Mosquitos Vetores/virologia , Pardais/virologia , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/isolamento & purificação , Animais , Anopheles/virologia , Culex/virologia , Humanos , Ochlerotatus/virologia , Densidade Demográfica , Estudos Soroepidemiológicos , Espanha/epidemiologia , Febre do Nilo Ocidental/transmissão
19.
Am J Trop Med Hyg ; 98(3): 883-890, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29363456

RESUMO

The objective of this work was to summarize and quantify Japanese encephalitis virus (JEV) infection, dissemination, and transmission rates in mosquitoes, using a meta-analysis approach. Data were obtained from experimental studies, gathered by means of a systematic review of the literature. Random-effects subgroup meta-analysis models by mosquito species were fitted to estimate pooled estimates and to calculate the variance between studies for three outcomes of interest: JEV infection, dissemination, and transmission rates in mosquitoes. To identify sources of heterogeneity among studies and to assess the association between different predictors (mosquito species, virus administration route, incubation period, and diagnostic method) with the outcome JEV infection rate in vectors, we fitted univariable meta-regression models. Mosquito species and administration route represented the main sources of heterogeneity associated with JEV infection rate in vectors. This study provided summary effect size estimates to be used as reference for other investigators when assessing transmission efficiency of vectors and explored sources of variability for JEV infection rates in vectors. Because transmission efficiency, as part of vector competence assessment, is an important parameter when studying the relative contribution of vectors to JEV transmission, our findings contribute to further our knowledge, potentially moving us toward more informed and targeted actions to prevent and control JEV in both affected and susceptible regions worldwide.


Assuntos
Aedes/virologia , Culex/virologia , Encefalite Japonesa/transmissão , Modelos Estatísticos , Mosquitos Vetores/virologia , Ochlerotatus/virologia , Animais , Ásia/epidemiologia , Vírus da Encefalite Japonesa (Espécie)/patogenicidade , Vírus da Encefalite Japonesa (Espécie)/fisiologia , Encefalite Japonesa/epidemiologia , Feminino , Humanos
20.
J Med Entomol ; 55(2): 342-350, 2018 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-29190386

RESUMO

Ration of food per capita of larval population is widely thought to limit mosquito production from container habitats, directly reflecting resource limitation. In this study, the importance of density-dependent resource limitation on larval Aedes triseriatus (Say) (Diptera: Culicidae) depended on the degree of microbial conditioning of senescent leaf detritus in surrogate tree holes. Density and ration strongly affected emergence, total female mass, and mean female mass of populations grown on leaves that had conditioned for 3 d, but had less impact when larval populations were grown on leaves that had conditioned for 1 mo. Ration per capita was a stronger predictor (50-94% of the variance) of all growth parameters measured for populations grown on leaves conditioned for 3 d compared with 1 mo (2-66% of variance), with the exception of development time. Larvae grew faster and to a larger body size on leaves conditioned for 3 d at low densities of larvae and a higher ration per capita. However, populations grown on leaves conditioned for 1 mo produced equal or more total mass and individuals of higher average mass than when grown on leaves conditioned for 3 d in treatments with low ration per capita. Well-conditioned detritus, representing the degree of microbial colonization of the organic material, must reflect the typical condition in tree holes with unconditioned leaves atypical. Therefore, results of this study suggest that experiments using well-conditioned leaves better estimate growth responses, including moderated density dependence and less importance of ration per capita, than experiments using unconditioned detritus.


Assuntos
Aedes/crescimento & desenvolvimento , Folhas de Planta/química , Animais , Feminino , Larva/crescimento & desenvolvimento , Masculino , Ochlerotatus/crescimento & desenvolvimento , Densidade Demográfica
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