Distribution,diversity and density of wolbachial infections in cladocerans and copepods from Thailand

Species of the genus Wolbachia comprise a group of Rickettsia-like, maternally-inherited bacteria that cause several reproductive alterations in arthropod hosts. The best known are cytoplasmic incompatibility and feminization. Here, the first systematic surveys of wolbachial infections in cladocerans and copepods from six geographic regions of Thailand, including Northern, Northeastern, Western, Central, Eastern and Southern are reported. Using gene amplification assays with wsp and groE primers, wolbachiae were detected in 239 (4 spp.) of 1885 (57 spp.) copepods and cladocerans from all regions of Thailand surveyed. Screening results obtained with wsp primers or groE primers were similar in all cases. The presence of wolbachiae was only detected in copepods, not in cladocerans. Sex ratio analyses of the progeny of two species of copepods, Mesocyclops aspericornis and Mesocyclops thermocyclopoides, naturally or artificially infected with wolbachiae showed infection causes feminization (female-bias). The relative density if infection in naturally infected populations of three copepod species, M. thermocyclopoides, Heliodiaptomus elegans and Neodiaptomus blachei, were determined using real-time quantitative PCR assay based on the wsp gene. The density of wolbachiae in M. thermocyclopoides was significantly higher than in the other two species. These results suggest that wolbachial infections are distributed throughout Thailand, and that possibly the natural occurrence of these in copepods may be due to their predation on mosquito larvae. This apparent novel biology may have importance as a genetic drive system for control of vector borne diseases in the future.     

Comparative morphology of the pyloric armature of adult mosquitoes (Diptera: Culicidae)

The structure of the pyloric armature, hypothesized to aid in blood-meal digestion or parasite resistance, was compared quantitatively among the following 8 species in 5 genera of adult mosquitoes from the southeastern United States: Aedes albopictus, Aedes japonicus, Aedes triseriatus, Anopheles punctipennis, Culex pipiens s.l., Culex restuans, Orthopodomyia signifera, and Toxorhynchites rutilus. Females differed significantly among species in the structure of spines composing the armature, with Aedes spp. forming one general group, Culex spp. another, and An. punctipennis and Or. signifera a third. Relationships of species based on structural characters of the armature were consistent with recent culicid phylogenies. Although pyloric armature has been noted in mosquitoes and other insects, this is the first quantitative investigation of the mosquito pyloric armature.     

Prevalence and molecular characterization of Wolbachia in field-collected Aedes albopictus,Anopheles sinensis,Armigeres subalbatus,Culex pipiens and Cx. tritaeniorhynchus in China

Wolbachia are maternally transmitted intracellular bacteria that can naturally and artificially infect arthropods and nematodes. Recently, they were applied to control the spread of mosquito-borne pathogens by causing cytoplasmic incompatibility (CI) between germ cells of females and males. The ability of Wolbachia to induce CI is based on the prevalence and polymorphism of Wolbachia in natural populations of mosquitoes. In this study, we screened the natural infection level and diversity of Wolbachia in field-collected mosquitoes from 25 provinces of China based on partial sequence of Wolbachia surface protein (wsp) gene and multilocus sequence typing (MLST). Among the samples, 2489 mosquitoes were captured from 24 provinces between July and September, 2014 and the remaining 1025 mosquitoes were collected month-by-month in Yangzhou, Jiangsu province between September 2013 and August 2014. Our results showed that the presence of Wolbachia was observed in mosquitoes of Aedes albopictus (97.1%, 331/341), Armigeres subalbatus (95.8%, 481/502), Culex pipiens (87.0%, 1525/1752), Cx. tritaeniorhynchus (17.1%, 14/82), but not Anopheles sinensis (n = 88). Phylogenetic analysis indicated that high polymorphism of wsp and MLST loci was observed in Ae. albopictus mosquitoes, while no or low polymorphisms were in Ar. subalbatus and Cx. pipiens mosquitoes. A total of 12 unique mutations of deduced amino acid were identified in the wsp sequences obtained in this study, including four mutations in Wolbachia supergroup A and eight mutations in supergroup B. This study revealed the prevalence and polymorphism of Wolbachia in mosquitoes in large-scale regions of China and will provide some useful information when performing Wolbachia-based mosquito biocontrol strategies in China.     

Mosquito Vector Diversity across Habitats in Central Thailand Endemic for Dengue and Other Arthropod-Borne Diseases

Recent years have seen the greatest ecological disturbances of our times, with global human expansion, species and habitat loss, climate change, and the emergence of new and previously-known infectious diseases. Biodiversity loss affects infectious disease risk by disrupting normal relationships between hosts and pathogens. Mosquito-borne pathogens respond to changing dynamics on multiple transmission levels and appear to increase in disturbed systems, yet current knowledge of mosquito diversity and the relative abundance of vectors as a function of habitat change is limited. We characterize mosquito communities across habitats with differing levels of anthropogenic ecological disturbance in central Thailand. During the 2008 rainy season, adult mosquito collections from 24 sites, representing 6 habitat types ranging from forest to urban, yielded 62,126 intact female mosquitoes (83,325 total mosquitoes) that were assigned to 109 taxa. Female mosquito abundance was highest in rice fields and lowest in forests. Diversity indices and rarefied species richness estimates indicate the mosquito fauna was more diverse in rural and less diverse in rice field habitats, while extrapolated estimates of true richness (Chao1 and ACE) indicated higher diversity in the forest and fragmented forest habitats and lower diversity in the urban. Culex sp. (Vishnui subgroup) was the most common taxon found overall and the most frequent in fragmented forest, rice field, rural, and suburban habitats. The distributions of species of medical importance differed significantly across habitat types and were always lowest in the intact, forest habitat. The relative abundance of key vector species, Aedes aegypti and Culex quinquefasciatus, was negatively correlated with diversity, suggesting that direct species interactions and/or habitat-mediated factors differentially affecting invasive disease vectors may be important mechanisms linking biodiversity loss to human health. Our results are an important first step for understanding the dynamics of mosquito vector distributions under changing environmental features across landscapes of Thailand.     

Effects of crowding and temperature on Wolbachia infection density among life cycle stages of Aedes albopictus

Species of the genus Wolbachia are a group of Rickettsia-like, maternally-inherited bacteria (gram negative), which cause various reproductive alterations in their arthropod and nematode hosts including cytoplasmic incompatibility (CI), male-killing, parthenogenesis and feminization. They can be divided into supergroups such as A and B based on phylogenetic analysis of 16S rDNA sequences. In this study, we examined the relative infection densities of Wolbachia strains among life cycle stages in the mosquito, Aedes albopictus in terms of crowding effect and temperature effect. A. albopictus is known to be superinfected with both A- and B-supergroup Wolbachia which cause CI. The relative Wolbachia densities within each individual mosquito were determined and quantified by using real-time quantitative PCR assay based on the wsp gene. We found that B-supergroup Wolbachia strain densities in this host species were consistently and significantly higher than in the A-supergroup. Larval crowding also reduced adult size of mosquitoes. Our results show clearly that the higher densities of mosquito larvae cause lower densities of Wolbachia strains. Examination of the effect of temperature on Wolbachia density in each stage of the mosquito clearly revealed a significant decrease in bacterial density following exposure to elevated temperature (37 °C) in both males and females.     

Clarithromycin and Amoxicillin Susceptibility of Helicobacter pylori Strains Isolated from Adult Patients with Gastric or Duodenal Ulcer in Italy

Wolbachia endosymbiotic bacteria are widespread in arthropods and are also present in filarial nematodes. Almost all filarial species so far examined have been found to harbor these endosymbionts. The sequences of only three genes have been published for nematode Wolbachia (i.e., the genes coding for the proteins FtsZ and catalase and for 16S rRNA). Here we present the sequences of the genes coding for the Wolbachia surface protein (WSP) from the endosymbionts of eight species of filaria. Complete gene sequences were obtained from the endosymbionts of two different species, Dirofilaria immitis and Brugia malayi. These sequences allowed us to design general primers for amplification of the wsp gene from the Wolbachia of all filarial species examined. For these species, partial WSP sequences (about 600 base pairs) were obtained with these primers. Phylogenetic analysis groups these nematode wsp sequences into a coherent cluster. Within the nematode cluster, wsp-based Wolbachia phylogeny matches a previous phylogeny obtained with ftsZ gene sequences, with a good consistency of the phylogeny of hosts (nematodes) and symbionts (Wolbachia). In addition, different individuals of the same host species (Dirofilaria immitis and Wuchereria bancrofti) show identical wsp gene sequences. Received: 10 January 2000 / Accepted: 22 February 2000     

Mosquito vector‐associated microbiota: Metabarcoding bacteria and eukaryotic symbionts across habitat types in Thailand endemic for dengue and other arthropod‐borne diseases

Vector‐borne diseases are a major health burden, yet factors affecting their spread are only partially understood. For example, microbial symbionts can impact mosquito reproduction, survival, and vectorial capacity, and hence affect disease transmission. Nonetheless, current knowledge of mosquito‐associated microbial communities is limited. To characterize the bacterial and eukaryotic microbial communities of multiple vector species collected from different habitat types in disease endemic areas, we employed next‐generation 454 pyrosequencing of 16S and 18S rRNA amplicon libraries, also known as metabarcoding. We investigated pooled whole adult mosquitoes of three medically important vectors, Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus, collected from different habitats across central Thailand where we previously characterized mosquito diversity. Our results indicate that diversity within the mosquito microbiota is low, with the majority of microbes assigned to one or a few taxa. Two of the most common eukaryotic and bacterial genera recovered (Ascogregarina and Wolbachia, respectively) are known mosquito endosymbionts with potentially parasitic and long evolutionary relationships with their hosts. Patterns of microbial composition and diversity appeared to differ by both vector species and habitat for a given species, although high variability between samples suggests a strong stochastic element to microbiota assembly. In general, our findings suggest that multiple factors, such as habitat condition and mosquito species identity, may influence overall microbial community composition, and thus provide a basis for further investigations into the interactions between vectors, their microbial communities, and human‐impacted landscapes that may ultimately affect vector‐borne disease risk.     

三带喙库蚊体内猪繁殖与呼吸综合征病毒的分离与鉴定

【目的】调查猪场蚊虫是否能携带猪繁殖与呼吸综合征(PRRS)病毒。【方法】采集发生PRRS疫情的3个养猪场蚊虫样本,采用RT-PCR方法检测PRRS病毒核酸,取阳性蚊虫样本接种Marc-145细胞进行病毒的分离培养,以间接免疫荧光抗体技术和分子克隆技术进行病毒的鉴定。【结果】 养猪场内的蚊虫主要有三带喙库蚊Culex tritaeniorhychus、凶小库蚊Culex modestus、中华按蚊Anopheles sinensis和骚扰阿蚊Armigeres obturbans,其中三带喙库蚊占86.76%;以PRRS病毒N基因引物进行扩增,三带喙库蚊样本呈现阳性反应,而其他蚊种均为阴性。在蚊虫接种的Marc-145细胞中可见细胞融合和空泡形成等细胞病变效应;用抗PRRS病毒N蛋白抗体和羊抗猪IgG(H+L)-FITC进行间接免疫荧光染色,感染细胞呈现黄绿色荧光;以NSP2基因引物进行RT-PCR扩增、克隆与测序,发现库蚊源病毒与相应猪场猪源病毒中相应基因的序列具有较高同源性。【结论】 三带喙库蚊为猪舍优势蚊种,并能携带猪繁殖与呼吸综合征病毒。     

Infection density,diversity, and distribution of Wolbachia bacteria in moths (Order Lepidoptera): First systematic report from Thailand

Members of the genus Wolbachia are a group of Rickettsia-like, intracellular, maternally inherited bacterial endosymbionts that infect a diverse range of insects and cause reproductive changes in their hosts. Although Wolbachia’s role in many insects has been extensively studied, only a little of their effects on host’s reproduction and their infection frequencies were reported in Lepidopteran which is one of the most diverse insects. Here, we present the first systematic survey of the Wolbachia infection status in different species of moths from three different geographic regions of Thailand, which was carried out during January to December in 2019 with the screening of 1,235 specimens in total of 58 moth species from 13 families. Specimens were collected from Khao Yai National Park (the Central and the Northeast regions), and Kaeng Krachan National Park (the West region). Infections of Wolbachia were screened by using polymerase chain reaction with 16S rRNA, ftsZ and wsp gene primers which the results indicated high rates of Wolbachia infection in moth populations from Thailand. Wolbachia was found in all different geographically populations in total of 625 individuals in total of 28 moth species from 9 families, including 144 individuals (46 males and 98 females) from the Central, 156 individuals (49 males and 107 females) from the Northeast, and 325 individuals (114 males and 211 females) from the West. The highest infection rate was 90.47% in the West populations and the average infection rate was 61.90%. The detection of Wolbachia in different moth populations from all regions was identical when all primers were used to screen for Wolbachia. The relative densities of Wolbachia within each individual were determined using quantitative real-time PCR and the result showed that there was a low Wolbachia infection density in these moth populations. These findings indicated that Wolbachia are distributed throughout the moth populations from Thailand.     

Pathogenicity Tests on Nine Mosquito Species and Several Non-target Organisms with Strelkovimermis spiculatus (Nemata Mermithidae)

Nine species of mosquitoes and several species of non-target aquatic organisms were tested for susceptibility to the mernaithid nematode, Strelkovimermis spiculatus. All species of Anopheles, Aedes, Culex, and Toxorhynchites exposed to S. spiculatus were susceptible. Of the nine mosquito species tested, C. pipiens quinquefasciatus had the greatest tolerance to initial invasion and the highest percent infection of those that survived. High levels of infection were also achieved with Aedes taeniorhynchus and A. albopictus, but these mosquitoes were significantly less tolerant to parasitism than C. pipiens quinquefasciatus. Strelkovimermis spiculatus did not infect or develop in any of the non-target hosts tested.     

Host range of the parasite Strelkovimermis spiculatus (Nematoda: Mermithidae) in Argentina mosquitoes

Strelkovimermis spiculatus ( Poinar and Camino 1986 ) is a nematode parasite of mosquitoes isolated from the Neotropical region. We investigated the host range of this parasite in mosquito populations for a better understanding of the dynamics of temporary breeding sites. Five grassy‐pool habitats filled by rainwater were sampled from the summer 2007 through the fall 2008. Eight mosquito species were collected: Anopheles albitarsis, Culex chidesteri, Culex dolosus, Culex maxi, Aedes albifasciatus, Psorophora ciliata, Psorophora cyanescens, and Psorophora albigenu. Six of these species were parasitized: Cx. chidesteri, Cx. dolosus, Cx. maxi, Ae. albifasciatus, Ps. ciliata, and Ps. cyanescens. The occurrence of this mermithid in natural mosquito populations was increased from the end of winter to the end of the spring. Prevalence ranged from 11% to 100%. High levels of infections were registered only in Ae. albifasciatus larvae, the most abundant mosquito species (95%), followed by Cx. dolosus (2.7%). Strelkovimermis spiculatus completed its development in all infected mosquito larvae. The presence of S. spiculatus in six natural mosquito populations increases the number of susceptible species to 24.     

Blood-meal preferences and avian malaria detection in mosquitoes (Diptera: Culicidae) captured at different land use types within a neotropical montane cloud forest matrix

Human activities modify environmental conditions, altering ecological interactions that can contribute to the increasing number of vector-borne pathogens affecting both human and wildlife populations. There is a dearth of knowledge about mosquitoes feeding preferences and their role as potential vectors of haemosporidian parasites, particularly in modified habitats. During 2013–2014 we sampled mosquitoes in five different land use types within a cloud forest matrix. From a total of 4107 adult mosquitoes, 90 were engorged. We extracted DNA from mosquito blood-meals, abdomens, and thoraxes, which belonged to seven different species. Seventeen specimens were positive for avian Plasmodium parasites. We were able to identify the blood-meal source of 10 mosquitoes, the identified vertebrate species were: Homo sapiens (Human), Sturnira hondurensis (Bat), and Bos taurus (Cow). Our results show that Culex restuans is positive for avian malaria and it is feeding on both humans and domestic animals at urban and peri-urban habitat types, where it is also an abundant species throughout the year. Furthermore, Aedes quadrivittatus, also positive for avian malaria, is feeding on humans in the well-preserved cloud forest, where this mosquito species is highly abundant. This study is the first in Mexico to provide reference data showing generalist mosquito feeding preferences and presence of avian Plasmodium at locations with different land use types.     

DsRed2 transient expression in Culex quinquefasciatus mosquitoes

Culex quinquefasciatus mosquitoes have been successfully genetically modified only once, despite the efforts of several laboratories to transform and establish a stable strain. We have developed a transient gene expression method, in Culex, that delivers plasmid DNA directly to the mosquito haemolymph and additional tissues. We were able to express DsRed2 fluorescent protein in adult Cx. quinquefasciatus mosquitoes by injecting plasmids directly into their thorax. The expression of DsRed2 in adult Cx. quinquefasciatus mosquitoes is an important stepping stone to genetic transformation and the potential use of new control strategies and genetic interactions.     

Behavioural and Electrophysiological Responses of Mosquito Vectors <Emphasis Type="Italic">Aedes aegypti,Anopheles stephensi</Emphasis> and <Emphasis Type="Italic">Culex quinquefasciatus</Emphasis> to an Ethyl Ester: Ethyl 2-aminobenzoate

Mosquito control using different methods remains an integral component of intervention programmes which aim to protect humans from various mosquito-borne diseases. The host seeking behaviour of mosquitoes is essentially guided by odorant receptor neurons housed in the antenna, maxillary palps and proboscis. The odorant receptor neurons are responsible for detecting chemical cues from hosts and also useful for developing sustainable mosquito-control strategies that exploit host-seeking behaviours. The present investigation evaluates host seeking behavioural responses of a novel, non-toxic and environment friendly repellent, ethyl 2-aminobenzoate against three known vector species of mosquitoes viz. Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus maintained in laboratory. The flight orientation of the test mosquitoes was studied using Y-tube olfactometer, whereas the antennae of adult female mosquitoes were used to investigate the effect of ethyl 2-aminobenzoate on the peripheral olfactory system using electroantennogram (EAG). The findings demonstrate that ethyl 2-aminobenzoate exhibited significant response in Y-tube olfactometer against all the three known vector species of mosquitoes. However, only Anopheles stephensi significantly elicited responses in EAG experiments, while the responses obtained for Aedes aegypti and Culex quinquefasciatus were not statistically significant. The results conclude that currently evaluated chemical ethyl 2-aminobenzoate has potential against some well established mosquito vector species and could be exploited to develop new and comparatively more effective anti-mosquito formulations.     

Combining hydrology and mosquito population models to identify the drivers of rift valley Fever emergence in semi-arid regions of west Africa

Background

Rift Valley fever (RVF) is a vector-borne viral zoonosis of increasing global importance. RVF virus (RVFV) is transmitted either through exposure to infected animals or through bites from different species of infected mosquitoes, mainly of Aedes and Culex genera. These mosquitoes are very sensitive to environmental conditions, which may determine their presence, biology, and abundance. In East Africa, RVF outbreaks are known to be closely associated with heavy rainfall events, unlike in the semi-arid regions of West Africa where the drivers of RVF emergence remain poorly understood. The assumed importance of temporary ponds and rainfall temporal distribution therefore needs to be investigated.

Methodology/Principal Findings

A hydrological model is combined with a mosquito population model to predict the abundance of the two main mosquito species (Aedes vexans and Culex poicilipes) involved in RVFV transmission in Senegal. The study area is an agropastoral zone located in the Ferlo Valley, characterized by a dense network of temporary water ponds which constitute mosquito breeding sites.The hydrological model uses daily rainfall as input to simulate variations of pond surface areas. The mosquito population model is mechanistic, considers both aquatic and adult stages and is driven by pond dynamics. Once validated using hydrological and entomological field data, the model was used to simulate the abundance dynamics of the two mosquito species over a 43-year period (1961–2003). We analysed the predicted dynamics of mosquito populations with regards to the years of main outbreaks. The results showed that the main RVF outbreaks occurred during years with simultaneous high abundances of both species.

Conclusion/Significance

Our study provides for the first time a mechanistic insight on RVFV transmission in West Africa. It highlights the complementary roles of Aedes vexans and Culex poicilipes mosquitoes in virus transmission, and recommends the identification of rainfall patterns favourable for RVFV amplification.     

Sensilla basiconica (grooved pegs) on the antennae of female mosquitoes: electrophysiology and morphology

The sensilla basiconica or grooved pegs of mosquitoes consist of two morphologically and functionally distinct classes. Short grooved pegs house sensory cells that are excited by lactic acid whereas lactic acid-excited cells are absent in long grooved pegs. This correlation was found in four species of mosquito examined:Aedes aegypti, Aedes atropalpus, Aedes epactius, andCulex pipiens. InAedes epactius, both short and long grooved pegs house receptors that are sensitive to butyric acid.     

The effect of parasitism by the mermithid Romanomermis culicivorax on the dry weight and hemolymph soluble protein content of three species of mosquitoes

The dry weight, hemolymph soluble protein composition, and content of three species of mosquitoes, Culex pipiens, Aedes taeniorhynchus, and Anopheles quadrimaculatus were examined to determine the effects of parasitism by the mermithid nematode Romanomermis culicivorax. The dry weights of infected fourth-stage larvae of all three species were significantly lower than controls. The differences in weight found between infected early and late C. pipiens and A. quadrimaculatus larvae were attributed to the weight of the parasite itself. This difference was not noticeable in A. taeniorhynchus larvae. Hemolymph proteins were severely depleted in all three mosquito species during parasitism by R. culicivorax. Analysis of protein composition by PAGE showed that these depletions were accompanied by a reduction in the number of proteins. Differences between protein composition concentrations were evident between early and late fourthstage control larvae of C. pipiens and A. quadrimaculatus. The concentration of some low-molecular-weight proteins (below 68,000) remained constant between infected and control samples of all three mosquito species.     

Larval mortality of Culex tarsalis and Aedes aegypti when reared with different concentrations of Tetrahymena pyriformis

The paucity of information on infection and pathogenicity of mosquito larvae by ciliates under experimental conditions prompted the evaluation of the relationship between a clone of Tetrahymena pyriformis and two species of mosquitoes, Aedes aegypti and Culex tarsalis. A significant difference in mortality was observed between the two mosquito species when they were exposed to identical concentrations of ciliates. In rearing trays containing high concentrations of T. pyriformis, 76.3% of the C. tarsalis larvae died. Under similar conditions, death occurred in less than 3.0% of the A. aegypti larvae. Three figures illustrate daily results of these studies. Three criteria for facultative parasites are listed, and one, route of entry into the host, is discussed in detail.     

Deforestation and vector-borne disease: Forest conversion favors important mosquito vectors of human pathogens

The global burden of vector-borne diseases accounts for more than 17% of infectious diseases in humans. Rapid global expansion of previously obscure pathogens, such as Zika and chikungunya viruses in recent years highlights the importance of understanding how anthropogenic changes influence emergence and spillover of vector-borne diseases. Deforestation has been identified as one anthropogenic change that influences vector-borne disease prevalence, although contrasting pictures of the effects of deforestation on vector-borne disease transmission have been reported. These conflicting findings are likely attributable to the inherent complexity of vector-borne disease systems, which involve diverse groups of vectors, hosts and pathogens, depending on geography. The current study represents a quantitative exploration of the link between deforestation and mosquitoes, the most important common constituents of vector-borne disease systems. Analysis of data compiled from published field studies for 87 mosquito species from 12 countries revealed that about half of the species (52.9%) were associated with deforested habitats. Of these species that are favored by deforestation, a much larger percentage (56.5%) are confirmed vectors of human pathogens, compared to those negatively impacted by deforestation (27.5%). Moreover, species that serve as vectors of multiple human pathogens were all favored by deforestation, including Anopheles bancroftii, Anopheles darlingi, Anopheles farauti, Anopheles funestus s.l., Anopheles gambiae s.l., Anopheles subpictus, Aedes aegypti, Aedes vigilax, Culex annulirostris, and Culex quinquefasciatus. Our quantitative analysis of vector and non-vector species, demonstrates that the net effect of deforestation favors mosquitoes that serve as vectors of human disease, while the obverse holds true for non-vectors species. These results begin to unify our understanding of the relationship between deforestation and vector mosquitoes, an important step in quantifying how land use change, specifically deforestation, affects human risk of vector-borne disease.     

Landscape Effects on the Presence,Abundance and Diversity of Mosquitoes in Mediterranean Wetlands

Environment determines the distribution of mosquito-borne diseases in that it influences the vector-host-pathogen transmission cycle, including vector distribution, abundance and diversity. In this study, we analyse the relationship between environmental variables estimated by remote sensing and the spatial distribution (presence, abundance and diversity) of seven mosquito species vectors of West Nile and other pathogens (Usutu, avian malaria and dirofilariasis) in the Doñana Natural Park, Spain. Traps were distributed over an area of 54,984 ha divided into six ecological units: marshland, sand dunes, scrubland, ricefields, crops and fishponds. We collected mosquitoes once a month from up to 112 locations using BG-Sentinel traps baited with BG-lure and CO₂ during March-November 2010. Hydroperiod, NDVI and Inundation surface were estimated at several resolution scales (100, 250, 500, 1000 and 2000 metres) from corrected and normalized Landsat Images. We sampled 972,346 female mosquitoes, the most abundant species being Culex theileri, Ochlerotatus caspius, Culex modestus, Culex perexiguus, Culex pipiens, Anopheles atroparvus and Ochlerotatus detritus. Our results suggest that: (1) hydroperiod, inundation surface and NDVI are strongly related to the spatial distribution of mosquitoes; (2) the spatial scales used to measure these variables affected quantification of these relationships, the larger scale being more informative; (3) these relationships are species-specific; (4) hydroperiod is negatively related to mosquito presence and richness; (5) Culex abundance is positively related to hydroperiod; (6) NDVI is positively related to mosquito diversity, presence and abundance, except in the case of the two salt marsh species (Oc. caspius and Oc. detritus); and (7) inundation surfaces positively condition the abundance and richness of most species except the salt marsh mosquitoes. Remote sensing data provided reliable information for monitoring mosquito populations. Landscape significantly affected mosquito distribution and abundance, and as a result may alter disease risk. These results suggest that while environmental conditions affect the distribution and abundance of mosquitoes, other factors such as human modification of landscapes may give rise to significant changes in mosquito populations and consequently disease risk.