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Climate, land use and land cover change influence infectious disease dynamics, particularly vector-borne diseases. Knowledge about mosquito ecology in southern Indiana is limited. Here, we present results from a season long study where we sampled mosquitoes at the Hickory Ridge Fire Tower in Hoosier National Forest, Monroe County, Indiana, USA. Using BG-Pro traps with BG-Lure and LED lights weekly from 23 May to 31 October 2023, we collected 178 mosquitoes over 24 weeks of sampling, encompassing a total of 120 trap-nights, with an average of 1.48 ± 3.41 (SD) mosquitoes per trap-night. The species accumulation curve for all the samples was flat, indicating a comprehensive sampling of species. We collected 10 species with a Chao2 ± SE species richness estimate of 14.46 ± 7.14. The dominant species was Aedes vexans (n = 58, 36%), followed by Culex spp. (composed of morphologically indistinguishable Culex pipiens and Culex restuans) (n = 51, 31%), Culex erraticus (n = 16, 10%), and Aedes triseriatus (n = 15, 9%). Because mosquitoes are ectothermic, they are highly sensitive to microclimatic variables such as temperature, humidity, and rainfall. Our time series analysis showed a significant association of mosquito abundance with the variability (SD and kurtosis) of the environmental variables we studied highlighting the importance of weather fluctuations in mosquito ecology. Our study highlights how weather variability shapes mosquito abundance, thus impacting disease vectors like Culex spp. and Aedes triseriatus with implications for arbovirus transmission in the context of climate change. [ABSTRACT FROM AUTHOR]

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Aedes species are vectors of the most significant arboviruses in Brazil with the greatest health and economic impact in the country. However, little is known about the factors that influence the distribution of Aedes, as well as other container-breeding mosquitoes, especially on the border between urban and forest environments. Here, we tested the effect of three phytophysiognomies within the city–forest ecotone in the Brazilian semi-arid region on the spatial distribution of vector mosquitoes. We also investigated the effect of rainfall on the spatial distribution and abundance of mosquitoes and described the interspecific interactions between invasive and native mosquito species. Immatures were sampled during the rainy seasons of 2019–2020 (October 2019 to February 2020) and 2020–2021 (November 2020 to February 2021). In each sampled location, 30 ovitraps were installed in shaded areas. There was a predominance of the Aedes mosquitoes, especially Ae. albopictus and Ae. aegypti, while three species of Haemagogus (Hg. spegazzinii, Hg. janthinomys and Hg. leucocelaenus) were rarely found. The sylvatic mosquito Ae. terrens was abundant in areas with lower anthropic influence and during higher rainfall regimes with minimal pluviometric variation. This rainfall was also favorable for the presence of the predatory mosquito larvae Toxorhynchites theobaldi. The abundance of invasive Aedes species showed positive correlations with each other and negative correlations with the sylvatic Ae. terrens. Our results demonstrate that human occupation and the rainfall regime affect the interactions between invasive and sylvatic species of container mosquitoes. [ABSTRACT FROM AUTHOR]

Knowing the composition of mosquito community, their temporal dynamics and relationship with abiotic factors in urban areas is of interest in public health because many species are vectors of pathogens. This is the first survey of diurnal adult mosquitoes in an urban reserve in Buenos Aires City (Argentina). Fortnightly daytime samples were carried out during a year affected by a drought due to La Niña effect, to describe the adult mosquito community and analyze its association with environmental variables. Ten species belonging to the genera Culex L., Aedes Meigen, Psorophora Robineau-Desvoidy and Mansonia Blanchard were captured, some of which are vectors of pathogens (e.g. Aedes albifasciatus (Macquart) and the complex Culex pipiens L.). Diversity did not vary significantly among seasons, and the composition was moderately similar (ANOVA: p = 0.11; Dice-Sorensen: 0.50-0.77). However, classification of species as core, common or rare in the community varied. A canonical correspondence analysis allowed us to identify a group of five species associated with summer and high temperatures. The other species were not grouped, and were associated with rainfall, relative humidity or another season. These associations help to understand the presence and abundance of those species during a prolonged drought. [ABSTRACT FROM AUTHOR]

Additional vector control tools are needed to supplement current strategies to achieve malaria elimination and control of Aedes-borne diseases in many settings in Thailand and the Greater Mekong Sub-region. Within the next decade, the vector control community, Kasetsart University (KU), and the Ministry of Higher Education, Science, Research and Innovation must take full advantage of these tools that combine different active ingredients with different modes of action. Pu Teuy Mosquito Field Research Station (MFRS), Department of Entomology, Faculty of Agriculture, Kasetsart University (KU), Thailand was established in 2001 and has grown into a leading facility for performing high-quality vector biology and control studies and evaluation of public health insecticides that are operationally relevant. Several onsite mosquito research platforms have been established including experimental huts, a 40-m long semi-field screening enclosure, mosquito insectary, field-laboratory, and living quarters for students and researchers. Field research and assessments ranged from 'basic' investigations on mosquito biology, taxonomy and genetics to more 'applied' studies on responses of mosquitoes to insecticides including repellency, behavioural avoidance and toxicity. In the course of two decades, 51 peer-reviewed articles have been published, and 7 masters and 16 doctoral degrees in Entomology have been awarded to national and international students. Continued support of key national stakeholders will sustain MFRS as a Greater Mekong Subregion centre of excellence and a resource for both insecticide trials and entomological research. [ABSTRACT FROM AUTHOR]

Abstract Background Sugar feeding is a fundamental behaviour of many mosquito species. For Aedes albopictus, an important vector of dengue virus and chikungunya virus, little is known about its sugar-feeding behaviour, and no studies have been conducted on this in the southern hemisphere. This knowledge is pivotal for determining the potential of attractive targeted sugar baits (ATSBs) to control this important vector. Methods The prevalence of sugar was assessed in 1808 Ae. albopictus from Masig Island, Torres Strait, Australia collected between 13 and 25 March 2020. Fructose presence and content in field-collected Ae. albopictus were quantified using the cold anthrone assay. Results Significantly more male (35.8%) than female (28.4%) Ae. albopictus were sugar fed. There was a significant interaction between sex and time of day on the probability of capturing sugar-fed Ae. albopictus. For both sexes, fructose prevalence and content were higher in mosquitoes caught in the morning than in the afternoon. Female Ae. albopictus collected in the residential habitat were significantly more likely to be sugar fed than those collected in the woodland habitat. Conclusions These findings provide baseline information about the sugar-feeding patterns of Ae. albopictus and provide essential information to enable an assessment of the potential of ATSBs for vector suppression and control on Masig Island, with relevance to other locations where this species occurs. Graphical abstract

The Amazon rainforest is considered the largest reservoir of culicids and arboviruses in the world. It has been under intense human‐driven alteration, especially in the so‐called 'Arc of Deforestation', located in the eastern and southern regions. The emergence and transmission of infectious diseases are increasing, potentially due to land‐use change. We used landscape‐scale mosquito surveillance across a forest fragmentation gradient in the southern Amazon to evaluate the relationship between forest disturbance and the composition and structure of mosquito communities with a particular focus on the potential for arbovirus emergence in the region. Generalized linear models and logistic regression were used to associate the degree of landscape disturbance with arbovirus vectors' richness and abundance. A total of 1,960 culicids, belonging to 50 species, were collected from 2015 to 2016. Among these species, 20 have been associated with the transmission of arboviruses. Our results show an association of land use, more specifically small size of forest remnants with more irregular shape and higher edge density, with the increase of arbovirus vectors' richness and abundance. Six species of mosquito vectors exhibited a higher probability of occurrence in landscapes with medium or high degrees of disturbance. Our results indicate that land‐use change influences mosquito communities with potential implications for the emergence of arboviruses. [ABSTRACT FROM AUTHOR]

Additional vector control tools are needed to supplement current strategies to achieve malaria elimination and control of Aedes-borne diseases in many settings in Thailand and the Greater Mekong Sub-region. Within the next decade, the vector control community, Kasetsart University (KU), and the Ministry of Higher Education, Science, Research and Innovation must take full advantage of these tools that combine different active ingredients with different modes of action. Pu Teuy Mosquito Field Research Station (MFRS), Department of Entomology, Faculty of Agriculture, Kasetsart University (KU), Thailand was established in 2001 and has grown into a leading facility for performing high-quality vector biology and control studies and evaluation of public health insecticides that are operationally relevant. Several onsite mosquito research platforms have been established including experimental huts, a 40-m long semi-field screening enclosure, mosquito insectary, field-laboratory, and living quarters for students and researchers. Field research and assessments ranged from 'basic' investigations on mosquito biology, taxonomy and genetics to more 'applied' studies on responses of mosquitoes to insecticides including repellency, behavioural avoidance and toxicity. In the course of two decades, 51 peer-reviewed articles have been published, and 7 masters and 16 doctoral degrees in Entomology have been awarded to national and international students. Continued support of key national stakeholders will sustain MFRS as a Greater Mekong Subregion centre of excellence and a resource for both insecticide trials and entomological research. [ABSTRACT FROM AUTHOR]

The preimaginal bioecology of Culicidae was studied in north central Algeria for a year in 7 breeding sites, including 3 in Algiers, 3 in the Marais de Réghaia and 1 near the Sébaou river in Tizi-Ouzou. 13 Culicide species have been identified, including one belonging to Anophelinae and 12 to Culicinae. In the suburban Algiers region, the most abundant of which are Culiseta longiareolata, an ornithophile species with 57% of collections and Culex pipiens, antropophilic species with 39%. In the Sébaou river Culex pipiens largely dominates with 86%. The Réghaia marsh has the highest specific richness; the most abundant species are Culex impudicus with 44%, batracophile species and Culex pipiens with 28%. The spatiotemporal dynamics of Culex pipiens deposits, Culex. impudicus and Culiseta longiareolata, shows that the methods of impoundment of the sites and the variations of the physico-chemical factors of the water cause the eggs to hatch, give rhythm to the functioning of the sites and their productivity. The intensity of emergence is highest during the spring and fall season. In addition, the amplitude of the hibernation period and the speed of development of the generations are influenced by the vagaries of the sub-humid climate. This study contributes to the understanding of the bioecology of the aquatic stages of mosquitoes, a prerequisite for effective control. [ABSTRACT FROM AUTHOR]

Background: Sugar feeding is a fundamental behaviour of many mosquito species. For Aedes albopictus, an important vector of dengue virus and chikungunya virus, little is known about its sugar-feeding behaviour, and no studies have been conducted on this in the southern hemisphere. This knowledge is pivotal for determining the potential of attractive targeted sugar baits (ATSBs) to control this important vector. Methods: The prevalence of sugar was assessed in 1808 Ae. albopictus from Masig Island, Torres Strait, Australia collected between 13 and 25 March 2020. Fructose presence and content in field-collected Ae. albopictus were quantified using the cold anthrone assay. Results: Significantly more male (35.8%) than female (28.4%) Ae. albopictus were sugar fed. There was a significant interaction between sex and time of day on the probability of capturing sugar-fed Ae. albopictus. For both sexes, fructose prevalence and content were higher in mosquitoes caught in the morning than in the afternoon. Female Ae. albopictus collected in the residential habitat were significantly more likely to be sugar fed than those collected in the woodland habitat. Conclusions: These findings provide baseline information about the sugar-feeding patterns of Ae. albopictus and provide essential information to enable an assessment of the potential of ATSBs for vector suppression and control on Masig Island, with relevance to other locations where this species occurs. [ABSTRACT FROM AUTHOR]

Many mosquito species are considered as vectors of several pathogens responsible of serious infectious diseases including Malaria, Dengue, Chikungunia and Rift Valley Fever. The characterization of the larval habitat of these arthropods is an important step for a nuisance/vector control program. In this study we aimed to identify mosquito larvae species in the Tizi-Ouzou area (north-central of Algeria) and to examine the physico-chemical parameters of their permanent breeding sites. Surveys are carried out during the dry and rainy seasons (2018/2019), the larval stages of the mosquitoes were sampled using the dipping technique and the physico-chemical parameters of the breeding sites were measured. The morphotaxonomic examination of the Culicidae samples allowed the identification of 14 species belonging to five genera and two subfamilies. Interestingly, Culex pipiens was the most abundant species found in all entomological surveys. Moreover, Culex pipiens and Culiseta longiareolata species showed high ecological plasticity and were the best correlated species to the studied physico-chemical parameters. Temperature was positively correlated with the density of most inventoried species. Our data would be of great interest in the context of developing a nuisance control program and the prevention of vector-borne diseases. [ABSTRACT FROM AUTHOR]

Invasive mosquitoes are expanding their ranges into new geographic areas and interacting with resident mosquito species. Understanding how novel interactions can affect mosquito population dynamics is necessary to predict transmission risk at invasion fronts. Mosquito life‐history traits are extremely sensitive to temperature, and this can lead to temperature‐dependent competition between competing invasive mosquito species. We explored temperature‐dependent competition between Aedes aegypti and Anopheles stephensi, two invasive mosquito species whose distributions overlap in India, the Middle East, and North Africa, where An. stephensi is currently expanding into the endemic range of Ae. aegypti. We followed mosquito cohorts raised at different intraspecific and interspecific densities across five temperatures (16–32°C) to measure traits relevant for population growth and to estimate species' per capita growth rates. We then used these growth rates to derive each species' competitive ability at each temperature. We find strong evidence for asymmetric competition at all temperatures, with Ae. aegypti emerging as the dominant competitor. This was primarily because of differences in larval survival and development times across all temperatures that resulted in a higher estimated intrinsic growth rate and competitive tolerance estimate for Ae. aegypti compared to An. stephensi. The spread of An. stephensi into the African continent could lead to urban transmission of malaria, an otherwise rural disease, increasing the human population at risk and complicating malaria elimination efforts. Competition has resulted in habitat segregation of other invasive mosquito species, and our results suggest that it may play a role in determining the distribution of An. stephensi across its invasive range. [ABSTRACT FROM AUTHOR]

In vector control, it is widely accepted that killing adult mosquitoes would sharply reduce the proportion of old mosquitoes and cause the greatest changes to malaria transmission. The principle is based on a mathematical model of the sporozoite rate (the proportion of infective mosquitoes) that emphasized changes in mosquito age. Killing adult mosquitoes also reduces mosquito population densities, which are directly proportional to human biting rates (the number of bites, per person, per day). Eect sizes of vector control can be compared using sporozoite rates and human biting rates, which are commonly measured. We argue that human biting rates convey more use- ful information for planning, monitoring and evaluating vector control, and operational research should focus on understanding mosquito ecology. Killing adult mosquitoes with vector control is highly effective because it reduces transmission in several ways: (i) mosquitoes are less likely to become infected and less likely to survive long enough for parasites to become infective, which affects the sporozoite rate (SR); (ii) adult mosquitoes lay fewer eggs, so fewer adults emerge, and each emerging mosquito gives fewer bites, which reduces the human-biting rate (HBR). A simple test of the importance of age versus density involves comparing changes in the HBR with changes in the SR. In some cases, variability in transmission intensity and the success of malaria control is clearly due to variability or changes in the HBR. The effects of vector control on the HBR are unpredictable across ecological settings. To reduce uncertainty and improve the outcomes of vector control, entomological surveillance should prioritize measuring the HBR. [ABSTRACT FROM AUTHOR]

BACKGROUND Southeast Brazil has recently experienced a Yellow Fever virus (YFV) outbreak where the mosquito Haemagogus leucocelaenus was a primary vector. Climatic factors influence the abundance of mosquito vectors and arbovirus transmission. OBJECTIVES We aimed at describing the population dynamics of Hg. leucocelaenus in a county touched by the recent YFV outbreak. METHODS Fortnightly egg collections with ovitraps were performed from November 2012 to February 2017 in a forest in Nova Iguaçu, Rio de Janeiro, Brazil. The effects of mean temperature and rainfall on the Hg. leucocelaenus population dynamics were explored. FINDINGS Hg. leucocelaenus eggs were continuously collected throughout the study, with a peak in the warmer months (December-March). The climatic variables had a time-lagged effect and four weeks before sampling was the best predictor for the positivity of ovitraps and total number of eggs collected. The probability of finding > 50% positive ovitraps increased when the mean temperature was above 24ºC. The number of Hg. leucocelaenus eggs expressively increase when the mean temperature and accumulated precipitation surpassed 27ºC and 100 mm, respectively, although the effect of rainfall was less pronounced. MAIN CONCLUSIONS Monitoring population dynamics of Hg. leucocelaenus and climatic factors in YFV risk areas, especially mean temperature, may assist in developing climate-based surveillance procedures to timely strengthening prophylaxis and control.

Abstract Background Uranotaenia unguiculata Edwards, 1913 is a species of mosquito (Diptera: Culicidae) native to central Europe. Recently a novel lineage of the West Nile virus (WNV-lineage 4c) was identified in pools of adult female Ur. unguiculata. To increase the body of knowledge about this species, various trapping methods were evaluated to determine the most efficient method for capturing adult female Ur. unguiculata. Results Sound traps collected equivalent numbers of female Ur. unguiculata as low-hanging light-baited downdraft traps. Hosts were identified as Pelophylax lessonae and P. ridibunda (Anura: Ranidae) species group frogs from the blood found in engorged females. In addition to confirming infection by WNV-lin. 4c, a potentially integrated flavivirus sequence was detected in male mosquitoes. A novel Alphamesonivirus 1 (Nidovirales: Mesoniviridae) was found to be widespread in the Ur. unguiculata population and is herein described. Conclusions Efficient collection methods for Ur. unguiculata for arbovirus surveillance reflect mosquito questing behavior. Uranotaenia unguiculata targets frog species which call from the water, and it is likely that the novel WNV-lin. 4c is maintained in a frog-mosquito transmission cycle. The improved trapping methods listed here will assist future studies of the vector status of Ur. unguiculata for WNV and other arboviruses.

Over 390 million people worldwide are infected with dengue fever each year. In the absence of an effective vaccine for general use, national control programs must rely on hospital readiness and targeted vector control to prepare for epidemics, so accurate forecasting remains an important goal. Many dengue forecasting approaches have used environmental data linked to mosquito ecology to predict when epidemics will occur, but these have had mixed results. Conversely, human mobility, an important driver in the spatial spread of infection, is often ignored. Here we compare time-series forecasts of dengue fever in Thailand, integrating epidemiological data with mobility models generated from mobile phone data. We show that geographically-distant provinces strongly connected by human travel have more highly correlated dengue incidence than weakly connected provinces of the same distance, and that incorporating mobility data improves traditional time-series forecasting approaches. Notably, no single model or class of model always outperformed others. We propose an adaptive, mosaic forecasting approach for early warning systems. [ABSTRACT FROM AUTHOR]

Container Aedes mosquitoes are responsible for the transmission of anthroponotic and zoonotic viruses to people. The surveillance and control of these mosquitoes is an important part of public health protection and prevention of mosquito-borne disease. In this study, we surveyed 327 sites over 2 weeks in late June and early July in 2017 in North Carolina, USA for the presence and abundance of Aedes spp. eggs in an effort to better target potential Ae. aegypti collections. We examined the ability of 2 types of landscape data, Light Detection And Ranging (LIDAR) and National Land Cover Database (NLCD) to explain the presence and abundance of eggs using principal component analysis to deal with collinearity, followed by generalized linear regression. We explained variation of both egg presence and abundance for Aedes albopictus (Skuse) and Aedes triseriatus (Say) using both NLCD and LIDAR data. However, the ability to make robust predictions was limited by variation in the data. Increased sampling time and better landscape data would likely improve the predictive ability of our models, as would a better understanding of oviposition behavior. [ABSTRACT FROM AUTHOR]

In the 1940s, the medical entomologist Alexander J. Haddow and his expatriate and indigenous collaborators conducted intensive field studies of the relationships between mosquitos, monkeys, humans, and the yellow fever virus in Bwamba District, Uganda. In order to disentangle the complexities of these relationships, colonial scientists found it necessary to transform natural places into experimental spaces by importing non-native species, manufacturing novel structures, and manipulating the behavior of human residents. This work transformed Bwamba into a particular kind of place, a place constructed to represent nature and natural relationships to the trained and expert eye. In turn, Bwamba shaped the researchers' increasingly complex understanding of the natural cycles of yellow fever infection. Haddow's practices reveal the tension between the imperative to understand yellow fever holistically and the imperative to produce experimental results with laboratory-like precision and "placelessness" in mid-twentieth-century medical field research. [ABSTRACT FROM AUTHOR]

Temporary aquatic habitats are contingent on the allochthonous inputs of plant and animal detritus, whose quality and availability can significantly affect the species developing in these habitats. Although animal detritus (i.e., invertebrate carcasses) is a high-quality food, it is an unpredictable and variable resource. On the contrary, conspecific individuals (dead or alive) are a nutritionally high-quality food source that is always available. In this context, conspecifics consumption, by cannibalism or necrophagy, can be a good strategy to overcome nutrient limitation and allow individual maintenance and development. Here, we tested this hypothesis by using the tiger mosquito Aedes albopictus. By carrying out laboratory and semi-field experiments, we first estimated the relative rate of cannibalism and necrophagy, under different larval densities. Then, we analyzed the effects of cannibalism and necrophagy on larval survival and adult yield. Consistent with our hypothesis, we found that cannibalism and necrophagy occurred under all experimental conditions, and that conspecific consumption had positive effects on individual development, as it significantly increased the rate of adult emergence and larval survival. Interestingly, about 50% of the initial cohort was consumed by conspecifics, suggesting that cannibalism and necrophagy can drive an important resources loop in temporary aquatic habitats.

Metacommunity theory is a convenient framework in which to investigate how local communities linked by dispersal influence patterns of species distribution and abundance across large spatial scales. For organisms with complex life cycles, such as mosquitoes, different pressures are expected to act on communities due to behavioral and ecological partitioning of life stages. Adult females select habitats for oviposition, and resulting offspring are confined to that habitat until reaching adult stages capable of flight; outside‐container effects (OCE) (i.e., spatial factors) are thus expected to act more strongly on species distributions as a function of adult dispersal capability, which should be limited by geographic distances between sites. However, larval community dynamics within a habitat are influenced by inside‐container effects (ICE), mainly interactions with conspecifics and heterospecifics (e.g., through effects of competition and predation). We used a field experiment in a mainland‐island scenario to assess whether environmental, spatial, and temporal factors influence mosquito prey and predator distributions and abundances across spatial scales: within‐site, between‐site, and mainland‐island. We also evaluated whether predator abundances inside containers play a stronger role in shaping mosquito prey community structure than do OCE (e.g., spatial and environmental factors). Temporal influence was more important for predators than for prey mosquito community structure, and the changes in prey mosquito species composition over time appear to be driven by changes in predator abundances. There was a negligible effect of spatial and environmental factors on mosquito community structure, and temporal effects on mosquito abundances and distributions appear to be driven by changes in abundance of the dominant predator, perhaps because ICE are stronger than OCE due to larval habitat restriction, or because adult dispersal is not limited at the chosen spatial scales. [ABSTRACT FROM AUTHOR]

Abstract The Panamá Canal construction encompassed one of the first examples of malaria elimination. Nevertheless, malaria has uninterruptedly persisted in Native American populations living within a few kilometers of the Panamá Canal. Here, we present results from a monthly longitudinal study (May 2016 to March 2018), whose goal was to quantitatively describe seasonal patterns of Plasmodium spp. infection in Anopheles albimanus Wiedemann, and its association with environmental covariates, at Ipetí-Guna, a village within a region targeted for malaria elimination in Panamá. To detect Plasmodium spp. infections we employed a standard nested PCR on DNA extracts from mosquito pools of varying size, which were then used to estimate monthly infection rates using a maximum likelihood method. The infection rate estimates (IR) were analyzed using time series analysis methods to study their association with changes in rainfall, temperature, NDVI (a satellite derived vegetation index), malaria cases and human biting rates (HBR). We found that mosquitoes were infected by Plasmodium vivax mainly from September to December, reaching a peak in December. Time series modeling showed malaria IR in An albimanus increased, simultaneously with HBR, and IR in the previous month. These results suggest that elimination interventions, such as mass drug administration, are likely to be more effective if deployed from the middle to the end of the dry season (March and April at Ipetí-Guna), when the likelihood of malaria infection in mosquitoes is very low and when curtailing human infections driving infections in mosquitoes can reduce malaria transmission, and increase the chance for elimination. Highlights • Malaria remains an important vector-borne disease in Panamá, mainly affecting native Guna populations. • We describe seasonal population and Plasmodium spp. infection dynamics of Anopheles albimanus , a dominant malaria vector in Guna Territories. • We found malaria infections in An. albimanus mainly from September to December, infections were correlated with human biting rates. • Results suggest an ideal time for large scale mass drug administrations would be from the mid to late dry season, March and April in Panamá. [ABSTRACT FROM AUTHOR]

Abstract Background Exotic invasive plants alter the structure and function of native ecosystems and may influence the distribution and abundance of arthropod disease vectors by modifying habitat quality. This study investigated how invasive plants alter the ecology of Culex pipiens, an important vector of West Nile virus (WNV) in northeastern and midwestern regions of the United States. Methods Field and laboratory experiments were conducted to test the hypothesis that three native leaf species (Rubus allegheniensis, blackberry; Sambucus canadensis, elderberry; and Amelanchier laevis, serviceberry), and three exotic invasive leaf species (Lonicera maackii, Amur honeysuckle; Elaeagnus umbellata, autumn olive; and Rosa multiflora, multiflora rose) alter Cx. pipiens oviposition site selection, emergence rates, development time, and adult body size. The relative abundance of seven bacterial phyla in infusions of the six leaf species also was determined using quantitative real-time polymerase chain reaction to test the hypothesis that variation in emergence, development, and oviposition site selection is correlated to differences in the diversity and abundance of bacteria associated with different leaf species, important determinants of nutrient quality and availability for mosquito larvae. Results Leaf detritus from invasive honeysuckle and autumn olive yielded significantly higher adult emergence rates compared to detritus from the remaining leaf species and honeysuckle alleviated the negative effects of intraspecific competition on adult emergence. Conversely, leaves of native blackberry acted as an ecological trap, generating high oviposition but low emergence rates. Variation in bacterial flora associated with different leaf species may explain this asymmetrical production of mosquitoes: emergence rates and oviposition rates were positively correlated to bacterial abundance and diversity, respectively. Conclusions We conclude that the displacement of native understory plant species by certain invasive shrubs may increase production of Cx. pipiens with potential negative repercussions for human and wildlife health. These findings may be relevant to mosquito control and invasive plant management practices in the geographic range of Cx. pipiens. Further, our discovery of a previously unknown ecological trap for an important vector of WNV has the potential to lead to novel alternatives to conventional insecticides in mosquito control by exploiting the apparent “attract-kill” properties of this native plant species.

Mosquitoes exhibit highly diverse and fast evolving odorant receptors (ORs). The indole-sensitive OR gene clade, comprised of Or2 and Or10 is a notable exception on account of its conservation in both mosquito subfamilies. This group of paralogous genes exhibits a complex developmental expression pattern in Aedes aegypti : AaegOr2 is expressed in both adults and larvae, AaegOr10 is adult-specific and a third member named AaegOr9 is larva-specific. OR2 and OR10 have been deorphanized and are selectively activated by indole and skatole, respectively. Using the two-electrode voltage clamp of Xenopus oocytes expressing Ae. aegypti ORs, we show that AaegOR9 is supersensitive and narrowly tuned to skatole. Our findings suggest that Ae. aegypti has evolved two distinct molecular strategies to detect skatole in aquatic and terrestrial environments, highlighting the central ecological roles of indolic compounds in the evolutionary and life histories of these insects. [ABSTRACT FROM AUTHOR]

Highlights • Two engineered underominance systems for mosquito control are investigated. • Male-only releases must be larger than bi-sex releases to trigger the gene drive. • Female-specific lethality averts more disease cases than bi-sex lethality. • Genetic lethality efficiency is less important than ambient transgene fitness cost. • Mating success and longevity of engineered insects strongly governs drive success. Abstract Underdominance gene drives are frequency-dependent drives that aim to spread a desired homozygote genotype within a population. When the desired homozygote is released above a threshold frequency, heterozygote fitness disadvantage acts to drive the desired trait to fixation. Underdominance drives have been proposed as a way to control vector-borne disease through population suppression and replacement in a spatially contained and reversible way—benefits that directly address potential safety concerns with gene drives. Here, ecological and epidemiological dynamics are coupled to a model of mosquito genetics to investigate theoretically the impact of different types of underdominance gene drive on disease prevalence. We model systems with two engineered alleles carried either on the same pair of chromosomes at the same locus or homozygously on different pairs at different loci, genetic lethality that affects both sexes or only females, and bi-sex or male-only releases. Further, the different genetic and ecological fitness costs that can arise from genetic modification and artificial rearing are investigated through their effect on the population threshold frequency that is required to trigger the drive mechanism. We show that male-only releases must be significantly larger than bi-sex releases to trigger the underdominance drive. In addition, we find that female-specific lethality averts a higher percentage of disease cases over a control period than does bi-sex lethality. Decreases in the genetic fitness of the engineered homozygotes can increase the underdominance threshold substantially, but we find that the mating success of transgenic mosquitoes with wild-type females (influenced by a lack of competitiveness or the evolution of behavioural resistance in the form of active female mate preference) and the longevity of artificially-reared mosquitoes are vitally important to the success chances of underdominance based gene drive control efforts. [ABSTRACT FROM AUTHOR]

1. The loss of intact forest via logging can influence vector‐borne disease dynamics in part by altering the abundance or diversity of mosquito species. Using an experimental field approach, we characterised how two types of logging (clearcut and repeat‐entry shelterwood) affected temperate forest mosquito abundance and diversity in southwestern Virginia. 2.From May to September in 2008–2010, infusion‐baited gravid traps were used to collect ovipositing female mosquitoes across experimental forest plots that varied in logging treatment. Of the 29 680 collected adult female mosquitoes, the three dominant taxa captured were Aedes triseriatus (55%), Aedes japonicus (21%), and Culex pipiens/restuans (20%). 3. Logging treatment had a significant effect on the overall number of female mosquitoes caught per trap night, with lower average abundance of females on both logged treatments relative to two types of unlogged, control plots. When the three most abundant mosquito species were examined separately, logging treatment significantly influenced the abundance of both Aedes species, but did not significantly affect C. pipiens/restuans abundance. 4. Logging treatment did not influence the richness or diversity of mosquito species captured in gravid traps. However, logging treatment significantly altered the multivariate community composition of captured mosquitoes, an effect probably mediated by differential species‐specific impacts of logging on abundance. 5. Overall, the results of the present study suggest that the risk of arboviruses transmitted by container‐breeding Aedes species may be lower following a logging event in Appalachian forests because of reduced A. japonicus and A. triseriatus abundance with logging. [ABSTRACT FROM AUTHOR]

Mosquito-borne diseases remain a significant threat to public health and economics. Since mosquitoes are quite sensitive to temperature, global warming may not only worsen the disease transmission case in current endemic areas but also facilitate mosquito population together with pathogens to establish in new regions. Therefore, understanding mosquito population dynamics under the impact of temperature is considerably important for making disease control policies. In this paper, we develop a stage-structured mosquito population model in the environment of a temperature-controlled experiment. The model turns out to be a system of periodic delay differential equations with periodic delays. We show that the basic reproduction number is a threshold parameter which determines whether the mosquito population goes to extinction or remains persistent. We then estimate the parameter values for Aedes aegypti, the mosquito that transmits dengue virus. We verify the analytic result by numerical simulations with the temperature data of Colombo, Sri Lanka where a dengue outbreak occurred in 2017. [ABSTRACT FROM AUTHOR]

Abstract: To successfully implement surveillance or control strategies for mosquitoes, up‐to‐date knowledge of regional species composition is vital. The last report regarding mosquitoes (Diptera: Culicidae) in the Åland archipelago, southwestern Finland listed 19 species (Utrio, 1979). To determine the current species diversity, one collection trip was made to mainland Åland in 2015 and three in 2016. Mosquitoes (n = 3286) were collected as both adult and immature life stages from 88 collections within 29 1‐km2 areas. Fifteen of the 19 previously reported species were obtained, leaving the current status of four species uncertain. At least 11 species previously not reported from Åland, but confirmed on the Finnish mainland, were collected. Aedes geminus Peus was identified based on examination of the gonostylus, and represents a new species distribution for Finland. Anopheles maculipennis s.s. Meigen was confirmed from cytochrome c oxidase subunit I (COI) and internal transcribed spacer 2 (ITS2) sequence data and is reinstated on the list of Finnish species, along with Ochlerotatus sticticus (Meigen). Dahliana geniculata (Olivier) was found in two locations, in 2 months, indicating that there is an established population in Åland. The present data confirm that at least 27 species inhabit mainland Åland, rising to 31 when historical data are included. The Finnish mosquito fauna is increased from 38 to 41 species. [ABSTRACT FROM AUTHOR]

Water-holding tree holes are main larval habitats for many pathogen vectors, especially mosquitoes (Diptera: Culicidae). Along 3 years, the diversity and composition of mosquito species in tree holes of two neighbouring but completely different environments, a city and its adjacent forest, were compared using generalized linear mixed models, PERMANOVA, SIMPER and species association indexes. The city area (Northwest Argentina) is highly relevant epidemiologically due to the presence of Aedes aegypti L. (main dengue vector) and occurrence of dengue outbreaks; the Yungas rainforests are highly biologically diverse. In total seven mosquito species were recorded, in descending order of abundance: Ae. aegypti, Haemagogus spegazzinii Brèthes, Sabethes purpureus (Theobald), Toxorhynchites guadeloupensis Dyar and Knab, Aedes terrens Walker, Haemagogus leucocelaenus Dyar & Shannon and Sabethes petrocchiae (Shannon and Del Ponte). The seven mosquito species were recorded in both city sites and forested areas; however, their mosquito communities significantly diverged because of marked differences in the frequency and relative abundance of some species: Tx. guadeloupensis and Ae. aegypti were significantly more abundant in forest and urban areas, respectively. Positive significant associations were detected between Ae. aegypti, Hg. spegazzinii and Hg. leucocelaenus. The combined presence of Ae. aegypti, Haemagogus and Sabethes in the area also highlight a potential risk of yellow fever epidemics. Overall results show an impoverished tree hole mosquito fauna in urban environments, reflecting negative effects of urbanization on mosquito diversity. [ABSTRACT FROM AUTHOR]

The ecology and environmental conditions of a habitat have profound influences on mosquito population abundance. As a result, mosquito species vary in their associations with particular habitat types, yet long-term studies showing how mosquito populations shift in a changing ecological landscape are lacking. To better understand how land use changes influence mosquito populations, we examined mosquito surveillance data over a thirty-four-year period for two contrasting sites in central Iowa. One site displayed increasing levels of urbanization over time and a dramatic decline in Culex pipiens group (an informal grouping of Culex restuans, Culex pipiens, and Culex salinarius, referred to as CPG), the primary vectors of West Nile virus in central Iowa. Similar effects were also shown for other mosquito vector populations, yet the abundance of Aedes vexans remained constant during the study period. This is in contrast to a second site, which reflected an established urban landscape. At this location, there were no significant changes in land use and CPG populations remained constant. Climate data (temperature, total precipitation) were compiled for each location to see if these changes could account for altered population dynamics, but neither significantly influence CPG abundance at the respective site locations. Taken together, our data suggest that increased landscape development can have negative impacts on Culex vector populations, and we argue that long-term surveillance paired with satellite imagery analysis are useful methods for measuring the impacts of rapid human development on mosquito vector communities. As a result, we believe that land use changes can have important implications for mosquito management practices, population modeling, and disease transmission dynamics.

Mosquitoes comprehend a group with a major impact on public health, because some species transmit parasites vertebrate hosts. Comparative studies between preserved environment and disturbed areas provide important epidemiological information, due to the major knowledge on species populational dynamics and the possibility of a contact between vector species and human population. This work aims to characterize and compare the fauna of mosquitoes in the Goytacazes National Forest (GNF) and surrounding area, in the State of Espírito Santo, in Brazil. Collections occurred simultaneously in a preserved environment and in a peridomicile, from 15:00 to 18:00, between July 2008 and May 2009. In each environment, it was used a modified trap of Shannon type. As a result, 1,490 specimens from 14 genera and 19 identified species were collected. The species diversity (H = 1.95), species richness (S = 17), equitability index (J = 0.68) and the number of collected specimens (n = 1,100) were higher in the forest environment. The plentiful species were respectively Aedes (Ochlerotatus) scapularis (Rondani, 1848), Culex (Culex) nigripalpus Theobald, 1901 and Aedes (Ochlerotatus) fulvus (Wiedemann, 1828). Our results demonstrate that the occurrence of vector species in this region increases the potential risk of diverse arboviruses occurrence, especially wild-type yellow fever. Keywords: Atlantic Forest, Disease Vector, Diversity, Richness, Yellow Fever. [ABSTRACT FROM AUTHOR]

Uranotaenia unguiculata is a thermophilic mosquito species frequently occurring in the Mediterranean. Its first detection in the southern German Upper Rhine Valley in 1994 represented its northernmost distribution limit for a long time. During recent mosquito monitoring activities, two specimens of the species were trapped at different localities, about 70 km apart, in northeastern Germany, some 300-km latitude north of previous collection sites. It is not known whether Ur. unguiculata is vector-competent for disease agents although specimens collected in the field were found infected with West Nile virus and Dirofilaria repens. The finding of the species in northern Germany is probably a further example of mosquito species spreading northwards as a consequence of climate warming. [ABSTRACT FROM AUTHOR]

Background: Uranotaenia unguiculata is a Palaearctic mosquito species with poorly known distribution and ecology. This study is aimed at filling the gap in our understanding of the species potential distribution and its environmental requirements through a species distribution modelling (SDM) exercise. Furthermore, aspects of the mosquito ecology that may be relevant to the epidemiology of certain zoonotic vector-borne diseases in Europe are discussed. Results: A maximum entropy (Maxent) modelling approach has been applied to predict the potential distribution of Ur. unguiculata in the Western Palaearctic. Along with the high accuracy and predictive power, the model reflects well the known species distribution and predicts as highly suitable some areas where the occurrence of the species is hitherto unknown. Conclusions: To our knowledge, the potential distribution of a mosquito species from the genus Uranotaenia is modelled for the first time. Provided that Ur. unguiculata is a widely-distributed species, and some pathogens of zoonotic concern have been detected in this mosquito on several occasions, the question regarding its host associations and possible epidemiological role warrants further investigation. [ABSTRACT FROM AUTHOR]

The objective of this study was to provide new insights on the egg-to-adult biological cycle and hatching rate of eggs of Haemagogus leucocelaenus, a species that transmits wild-type yellow fever in Brazil. Eggs were collected using oviposition traps, 'ovitraps,' in a fragment of the Atlantic Forest in Rio de Janeiro, Brazil, in October (Experiment 1) and November (Experiment 2), 2015. Thereafter, the eggs were subjected to 16 immersions, to test hatching rate and evaluate the average development time. Hg. leucocelaenus individuals kept in a climate-controlled chamber (28° ± 1°C) showed an average development period of 10.44±0.70 d, from the start of larval stage to adulthood. Immersion viability was 49.8% and 18.2% for Experiments 1 and 2, respectively. In both experiments, the hatching peak occurred during the first immersion, where 26% and 15% of eggs hatched in Experiments 1 and 2, respectively. These results provide new insights into the biology of Hg. leucocelaenus. [ABSTRACT FROM AUTHOR]

Background: A neglected aspect of alien invasive plant species is their influence on mosquito vector ecology and malaria transmission. Invasive plants that are highly attractive to Anopheles mosquitoes provide them with sugar that is critical to their survival. The effect on Anopheles mosquito populations was examined through a habitat manipulation experiment that removed the flowering branches of highly attractive Prosopis juliflora from selected villages in Mali, West Africa. Methods: Nine villages in the Bandiagara district of Mali were selected, six with flowering Prosopis juliflora, and three without. CDC-UV light traps were used to monitor their Anopheles spp. vector populations, and recorded their species composition, population size, age structure, and sugar feeding status. After 8 days, all of the flowering branches were removed from three villages and trap catches were analysed again. Results: Villages where flowering branches of the invasive shrub Prosopis juliflora were removed experienced a threefold drop in the older more dangerous Anopheles females. Population density dropped by 69.4% and the species composition shifted from being a mix of three species of the Anopheles gambiae complex to one dominated by Anopheles coluzzii. The proportion of sugar fed females dropped from 73 to 15% and males from 77 to 10%. Conclusions: This study demonstrates how an invasive plant shrub promotes the malaria parasite transmission capacity of African malaria vector mosquitoes. Proper management of invasive plants could potentially reduce mosquito populations and malaria transmission. [ABSTRACT FROM AUTHOR]

The reemergence and growing burden of mosquito-borne virus infections have incited public fear and growing research efforts to understand the mechanisms of infection-associated health outcomes and to provide better approaches for mosquito vector control. While efforts to develop therapeutics, vaccines, and novel genetic mosquito-control technologies are underway, many important underlying ecological questions remain that could significantly enhance our understanding and ability to predict and prevent transmission. Here, we review the current knowledge about the transmission ecology of two recent arbovirus invaders, the chikungunya and Zika viruses. We introduce the viruses and mosquito vectors, highlighting viral biology, historical routes of transmission, and viral mechanisms facilitating rapid global invasion. In addition, we review factors contributing to vector global invasiveness and transmission efficiency. We conclude with a discussion of how human-induced biotic and abiotic environmental changes facilitate mosquito-borne virus transmission, emphasizing critical gaps in understanding. These knowledge gaps are tremendous; much of our data on basic mosquito ecology in the field predate 1960, and the mosquitoes themselves, as well as the world they live in, have substantially changed. A concerted investment in understanding the basic ecology of these vectors, which serve as the main drivers of pathogen transmission in both wildlife and human populations, is now more important than ever. [ABSTRACT FROM AUTHOR]

Background: Experiments involving mosquito mark-release-recapture (MRR) design are helpful to determine abundance, survival and even recruitment of mosquito populations in the field. Obstacles in mosquito MRR protocols include marking limitations due to small individual size, short lifespan, low efficiency in capturing devices such as traps, and individual removal upon capture. These limitations usually make MRR analysis restricted to only abundance estimation or a combination of abundance and survivorship, and often generate a great degree of uncertainty about the estimations. Methodology/Principal findings: We present a set of Bayesian biodemographic models designed to fit data from most common mosquito recapture experiments. Using both field data and simulations, we consider model features such as capture efficiency, survival rates, removal of individuals due to capturing, and collection of pupae. These models permit estimation of abundance, survivorship of both marked and unmarked mosquitoes, if different, and recruitment rate. We analyze the accuracy of estimates by varying the number of released individuals, abundance, survivorship, and capture efficiency in multiple simulations. These methods can stand capture efficiencies as low as usually reported but their accuracy depends on the number of released mosquitoes, abundance and survivorship. We also show that gathering pupal counts allows estimating differences in survivorship between released mosquitoes and the unmarked population. Conclusion/Significance: These models are important both to reduce uncertainty in evaluating MMR experiments and also to help planning future MRR studies. [ABSTRACT FROM AUTHOR]

Considerable interest in the relationship between biodiversity and disease has recently captured the attention of the research community, with impor- tant public policy implications. In particular, malaria in the Amazon region is often cited as an example of how forest conservation can improve public health outcomes. However, despite a growing body of literature and an increased understanding of the relationship between malaria and land use / land cover change (LULC) in Amazonia, contradictions have emerged. While some studies report that deforestation increases malaria risk, others claim the opposite. Assessing malaria risk requires examination of dynamic processes among three main components: (i) the environment (i.e. LULC and landscape transformations), (ii) vector biology (e.g. mosquito species distributions, vector activity and life cycle, plasmodium infection rates), and (iii) human populations (e.g. forest-related activity, host susceptibility, movement patterns). In this paper, we conduct a systematic literature review on malaria risk and deforestation in the Amazon focusing on these three components. We explore key features that are likely to generate these contrasting results using the reviewed articles and our own data from Brazil and Peru, and conclude with suggestions for productive avenues in future research. This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'. [ABSTRACT FROM AUTHOR]

A novel strategy for controlling the spread of arboviral diseases such as dengue, Zika and chikungunya is to transform mosquito populations with virus-suppressing Wolbachia . In general, Wolbachia transinfected into mosquitoes induce fitness costs through lower viability or fecundity. These maternally inherited bacteria also produce a frequency-dependent advantage for infected females by inducing cytoplasmic incompatibility (CI), which kills the embryos produced by uninfected females mated to infected males. These competing effects, a frequency-dependent advantage and frequency-independent costs, produce bistable Wolbachia frequency dynamics. Above a threshold frequency, denoted p ˆ , CI drives fitness-decreasing Wolbachia transinfections through local populations; but below p ˆ , infection frequencies tend to decline to zero. If p ˆ is not too high, CI also drives spatial spread once infections become established over sufficiently large areas. We illustrate how simple models provide testable predictions concerning the spatial and temporal dynamics of Wolbachia introductions, focusing on rate of spatial spread, the shape of spreading waves, and the conditions for initiating spread from local introductions. First, we consider the robustness of diffusion-based predictions to incorporating two important features of w Mel- Aedes aegypti biology that may be inconsistent with the diffusion approximations, namely fast local dynamics induced by complete CI ( i . e ., all embryos produced from incompatible crosses die) and long-tailed, non-Gaussian dispersal. With complete CI, our numerical analyses show that long-tailed dispersal changes wave-width predictions only slightly; but it can significantly reduce wave speed relative to the diffusion prediction; it also allows smaller local introductions to initiate spatial spread. Second, we use approximations for p ˆ and dispersal distances to predict the outcome of 2013 releases of w Mel-infected Aedes aegypti in Cairns, Australia, Third, we describe new data from Ae. aegypti populations near Cairns, Australia that demonstrate long-distance dispersal and provide an approximate lower bound on p ˆ for w Mel in northeastern Australia. Finally, we apply our analyses to produce operational guidelines for efficient transformation of vector populations over large areas. We demonstrate that even very slow spatial spread, on the order of 10–20 m/month (as predicted), can produce area-wide population transformation within a few years following initial releases covering about 20–30% of the target area. [ABSTRACT FROM AUTHOR]

The bamboo mosquito, Tripteroides bambusa (Yamada) (Diptera: Culicidae), is a mosquito species ubiquitous across forested landscapes in Japan. During 2014 we sampled adult mosquitoes from May to November using a sweep net in Nagasaki, Japan. We recorded and managed our field data using Open Data Kit, which eased the overall process of data management before performing their statistical analysis. Here, we analyse the resulting biweekly time series of the bamboo mosquito abundance using time-series statistical techniques. Specifically, we test for density dependence in the population dynamics fitting the Ricker model. Parameter estimates for the Ricker model suggest that the bamboo mosquito is under density dependence regulation and that its population dynamics is stable. Our data also suggest the bamboo mosquito increased its abundance when temperature was more variable at our study site. Further work is warranted to better understand the linkage between the observed density dependence in the adults and the larvae of this mosquito species. [ABSTRACT FROM AUTHOR]

Energy reserves in mosquitoes are an indicator of fitness, linking larval effort in resource acquisition with adult survival and fecundity. In other words, life history strategies and disease transmission potential can be related to the amount of energy reserves. The energy reserves of four mosquitoes - Aedes aegypti, Aedes albopictus, Armigeres subalbatus and Culex quinquefasciatus (Diptera: Culicidae) - were calculated to justify species-specific differences in their life history strategies. Following repeated sampling of pupae from the respective larval habitats, the glycogen, sugar and lipid contents of individual mosquitoes were assessed and corroborated with pupal weight and adult wing length. Discriminant function analysis was used to acquire an initial reflection of the differences of the parameters among the sex and species of the mosquitoes considered in the study. Using logistic regression and ANOVA, the effects of species and sex as contributors to variations in energy reserves could be established. The results indicated that for all the mosquitoes, sex-specific differences were prominent with reference to the energy reserves. Species-specific differences in energy reserves reflect differences in resource acquisition and assimilation in the tissues, and thus the differences in the life history strategies of these four species. [ABSTRACT FROM AUTHOR]

Chromosome inversions have fascinated the scientific community, mainly because of their role in the rapid adaption of different taxa to changing environments. However, the ecological traits linked to chromosome inversions have been poorly studied. Here, we investigated the roles played by 23 chromosome inversions in the adaptation of the four major African malaria mosquitoes to local environments in Africa. We studied their distribution patterns by using spatially explicit modeling and characterized the ecogeographical determinants of each inversion range. We then performed hierarchical clustering and constrained ordination analyses to assess the spatial and ecological similarities among inversions. Our results show that most inversions are environmentally structured, suggesting that they are actively involved in processes of local adaptation. Some inversions exhibited similar geographical patterns and ecological requirements among the four mosquito species, providing evidence for parallel evolution. Conversely, common inversion polymorphisms between sibling species displayed divergent ecological patterns, suggesting that they might have a different adaptive role in each species. These results are in agreement with the finding that chromosomal inversions play a role in Anopheles ecotypic adaptation. This study establishes a strong ecological basis for future genome-based analyses to elucidate the genetic mechanisms of local adaptation in these four mosquitoes. [ABSTRACT FROM AUTHOR]

Used vehicle tires are a source of mosquito vectors and a means of their introduction and expansion. With the aim of assessing the effects of urbanisation on the main mosquito vectors in temperate Argentina, the infestation levels of Aedes aegypti (L.) and Culex pipiens L. were studied in used tires from highly urbanised cities to low-urbanised small towns in Buenos Aires. Immatures of both species accounted for 96% of the 9,722 individuals collected; the total individuals collected represented seven species. The percentage of water-filled tires containing mosquitoes [container index (CI)] was 33% and the percentage of infested sites [site index (SI)] was 65.2%. These indexes decreased significantly from low to high urbanisation levels for both mosquito species. The relative abundance (RA) of Ae. aegypti immatures was slightly higher toward large cities, but showed no difference for Cx. pipiens. The CI of shaded tires was significantly higher than the CI of exposed tires for both mosquito species. There was no difference in RA values between shaded and sunlit tires. The CI and the SI were highest during the summer across the urbanisation levels, except for Cx. pipiens, which continued to increase during the autumn in small towns. Results related to urbanisation gradient, sunlit exposure and seasonality are discussed.

Since the reinfestation of South American countries by Ae. aegypti, dengue fever (DF) and dengue hemorrhagic fever (DHF) have become a major public health concern. The aim of this paper was to review the information related with Aedes vectors and dengue in Argentina since the reintroduction of Ae. aegypti in 1986. The geographic distribution of Ae. albopictus is restricted to the Northeast, and that of Ae. aegypti has expanded towards the South and the West in comparison with the records during the eradication campaign in the 1960s. Since 1998, 4,718 DF cases have been reported concentrated in the provinces of Salta, Formosa, Misiones, Jujuy and Corrientes. Despite the circulation of three dengue virus serotypes (DENV-1, -2 and -3) in the North of the country, DHF has not occurred until the present. The information published over the last two decades regarding mosquito abundance, temporal variations, habitat characteristics, competition, and chemical and biological control, was reviewed. Considering the available information, issues pending in Argentina are discussed. The presence of three DENV, the potential spread of Ae. albopictus, and the predicted climate change suggest that dengue situation will get worse in the region. Research efforts should be increased in the Northern provinces, where DHF is currently an actual risk.