Mosquito Species Research Articles

MosAIC: An annotated collection of mosquito-associated bacteria with high-quality genome assemblies.

Mosquitoes transmit medically important human pathogens, including viruses like dengue virus and parasites such as Plasmodium spp., the causative agent of malaria. Mosquito microbiomes are critically important for the ability of mosquitoes to transmit disease-causing agents. However, while large collections of bacterial isolates and genomic data exist for vertebrate microbiomes, the vast majority of work in mosquitoes to date is based on 16S rRNA gene amplicon data that provides limited taxonomic resolution and no functional information. To address this gap and facilitate future studies using experimental microbiome manipulations, we generated a bacterial Mosquito-Associated Isolate Collection (MosAIC) consisting of 392 bacterial isolates with extensive metadata and high-quality draft genome assemblies that are publicly available, both isolates and sequence data, for use by the scientific community. MosAIC encompasses 142 species spanning 29 bacterial families, with members of the Enterobacteriaceae comprising 40% of the collection. Phylogenomic analysis of 3 genera, Enterobacter, Serratia, and Elizabethkingia, reveal lineages of mosquito-associated bacteria isolated from different mosquito species in multiple laboratories. Investigation into species' pangenomes further reveals clusters of genes specific to these lineages, which are of interest for future work to test for functions connected to mosquito host association. Altogether, we describe the generation of a physical collection of mosquito-associated bacterial isolates, their genomic data, and analyses of selected groups in context of genome data from closely related isolates, providing a unique, highly valuable resource for research on bacterial colonisation and adaptation within mosquito hosts. Future efforts will expand the collection to include broader geographic and host species representation, especially from individuals collected from field populations, as well as other mosquito-associated microbes, including fungi, archaea, and protozoa.

Australian Culex annulirostris mosquitoes are competent vectors for Japanese encephalitis virus genotype IV

Japanese encephalitis virus (JEV) is transmitted by Culex species of mosquitoes. In 2022, JEV belonging to a previously unrecognised lineage of genotype IV (GIV) caused a major outbreak of JE in South-eastern Australia, resulting in human cases and affecting piggeries. Cx. annulirostris has previously been implicated as the major vector of JEV in northern Australia where the virus has circulated since its first detection in 1995. Here, we showed that experimental infection of a laboratory colony of Australian Cx. annulirostris with the isolate JEV NSW/22 resulted in a 100% mosquito infection rate, with 87% of mosquito saliva samples testing positive by RT-qPCR at 14 days post-infection. Immunohistochemistry confirmed the presence of a replicating virus in the mosquito midgut and dissemination throughout the body, including the salivary glands. Our results also showed evidence of transovarial transmission of this virus; however, transstadial transmission from the eggs to the adult stage was not found. Comparison with an Indonesian isolate of GIV JEV and previous Australian isolates belonging to genotypes I and II showed that infection with JEV NSW/22 resulted in higher viral titres in the early stage of infection and higher proportions of mosquitoes with JEV-positive saliva, indicating a greater transmission potential compared to other isolates. This study provides compelling experimental evidence that Australian Cx. annulirostris is a highly efficient vector for the 2022 Australian JEV GIV outbreak strain.

Prediction of Lead Molecule Esculetin of Tridax procumbens against Zika Virus Envelope Protein

In the existing field of science, it is necessary for Siddha, Ayurveda therapists, to understand the interactions and to treat the target regions of the human system effectively. One of the most significant nightmares for scientists and medical professionals has been the Zika virus. Since the bite of the Aedes mosquito species has infected people worldwide with the Zika virus (Flavivirus). The human mechanism and infection control interactions of the Zika virus are still unclear. In addition, some herbal products may give a pathway to the treat the zika virus. Many herbs aim to regulate various diseases, but the herb Tridax procumbens has a key collection of pharmacological values for diseases. Traditional health practitioners have struggled to grasp the precise mechanism of linking existence and how to treat the disease, so the current Ayurinformatics approach and the evolving field are an idea of a modern medical science system. Here we examine the interaction of flavonoids procumbenetin and esculetin of Tridax procumbens with zika virus in silico docking and molecular simulation and ADME and toxicity profile for the drug candidate. Hereby we conclude that these two compounds have the property to suppress the ZIKA virus and are stable and active with ZIKA virus. Molecular docking of Esculetin and Procumbenetin with ZIKV 5JHM, they bind with each other on active site pockets ASP98, ARG99, GLY100, TRP101, GLY102, ASN103, GLY104, CYS105, GLY106, LEU107, PHE108, GLY109.

Investigation on chemical composition and insecticidal activity against Anopheles gambiae of essential oil obtained by co-distillation of Cymbopogon citratus and Hyptis suaveolens from Western Burkina Faso.

Essential oils of Cymbopogon citratus and Hyptis suaveolens are known for their insecticidal properties, but remain ineffective against mosquitoes resistant to synthetic insecticides. In order to improve insecticidal properties of these plants, this study aimed to investigate the chemical composition and insecticidal activity against Anopheles gambiae mosquitoes of essential oil obtained by co-distillation of dry leaves of C. citratus and H. suaveolens. Essential oils were extracted by hydrodistillation from dry leaves of C. citratus and H. suaveolens, separately, then from the mixture of the dry leaves of the two plants in mass ratio 50/50. Each pure essential oil and the mixture obtained either by co-distillation or by combining pure essential oils in volume ratio 50/50 were then analysed by GC/MS. All essential oils and Deltamethrin 0.05% (positive control) were tested on two species of mosquitoes of the genus Anopheles gambiae according to the World Health Organization standard methods. Essential oil obtained by co-distillation mainly contained piperitone (40.80%), 1,8-cineole (24.64%), p-menth-4(8)-ene (13.20%), limonene (6.09%) and α-pinene (4.73%). However, the mixture of pure essential oils of these two plants mostly contained geranial (20.74%), neral (16.42%), 1,8-cineole (19.79%), sabinene (6.03%) and β-pinene (3.87%). The essential oil of C. citratus mainly contained geranial (41.49%), neral (32.83%), β-myrcene (13.66%) and geraniol (3.49%) while the major constituents of essential oil of H. suaveolens were 1,8-cineole (39.58%), sabinene (12.06%), β-pinene (7.73%), α-terpinolene (6.72%) and (E)-caryophyllene (7.49%). At the dose of 1%, all essential oils, except that of H. suaveolens, induced about 100% of mortality on the sensitive species of An. gambiae. However, on the resistant species at the same dose, the essential oil obtained by co-distillation induced the highest mortality (53.44%). The essential oils of C. citratus, H. suaveolens and the mixture of the two pure essential oils caused respectively 2.47, 15.28 and 18.33% of mortality. The synthetic insecticide caused 100 and 14.84% of mortality respectively on the sensitive and resistant species of An. gambiae. Essential oil obtained by co-distillation showed good insecticidal efficacy against a resistant species of An. gambiae and might constitute a new solution to fight against mosquitoes resistant to synthetic insecticides.

MOSQUITO SPECIES DISTRIBUTION IN TIRES IN RURAL AND URBAN LANDSCAPES ACROSS NORTHERN KENTUCKY.

Discarded vehicle tires can be found in habitats spanning a human land-use gradient from rural to urban and create an ideal artificial container habitat for mosquito larval development. The purpose of this study was to examine mosquito species composition in discarded vehicle tires in rural and urban habitats. Discarded tires were placed at 6 rural and 6 urban forested sites and sampled weekly for juvenile mosquitoes. Adult traps were also placed at these sites and were sampled weekly. There was no significant difference between the total number of juvenile mosquitoes collected from tires in urban sites compared to rural sites, but significantly more Aedes triseriatus and Ae. albopictus juveniles were found in urban sites compared to rural sites. This study also found that significantly more adult mosquitoes were collected in urban sites compared to rural, but there were no significant differences found between sites when comparing individual species. The results of this study suggest discarded vehicle tires are important mosquito larval habitats across human-land-use gradients and that Ae. triseriatus may be more common in urban areas than previously thought.

Current and Future Probability of Occurrence of the Floodwater Mosquito Aedes vexans (Meigen, 1830) in the Netherlands

ABSTRACTAedes vexans (Meigen, 1830) is a floodwater mosquito species that may cause significant nuisance and can serve as a vector for multiple arboviruses. Its distribution is expected to shift in the future as a result of changes in climate and land use. Understanding these shifts is important for estimating future disease risk. This study aims to identify habitat suitability and probability of occurrence of A. vexans. Using the Netherlands as a case study, we utilised an occurrence dataset generated by the Netherlands Centre for Monitoring of Vectors. We employed an auto machine learning approach to model generation, using a variety of modelling methodologies, determining the optimal ratio of presence: Absence datapoints in the training data and ultimately creating a 10‐model ensemble. We selected predictor variables relating to weather, land use, soil properties, flood risk and salinity. The probability of A. vexans presence was predicted on a 1 km grid for both the current Dutch situation and for four scenarios for 2050. Our analysis identified temperature, soil type and land cover as the primary determinants influencing the probability of A. vexans occurrence. Future projections reveal an increase in the likelihood of A. vexans occurrence in the study area, particularly along major river corridors and in regions with increasing amounts of artificial and natural areas. Additionally, the mosquito season is predicted to become longer under all future scenarios. Insights provided in our study can also be applied to other similar areas, such as other north‐western European countries or other urban deltas. This study shows for the first time detailed future occurrence predictions and also future seasonal predictions for this mosquito species. Seasonal predictions allow researchers to study how disease risk changes throughout the year, something which is particularly valuable given the predicted lengthening of the mosquito (and thus disease transmission) season.

Enhancing mosquito classification through self-supervised learning

Traditional mosquito identification methods, relied on microscopic observation and morphological characteristics, often require significant expertise and experience, which can limit their effectiveness. This study introduces a self-supervised learning-based image classification model using the Bootstrap Your Own Latent (BYOL) algorithm, designed to enhance mosquito species identification efficiently. The BYOL algorithm offers a key advantage by eliminating the need for labeled data during pretraining, as it autonomously learns important features. During fine-tuning, the model requires only a small fraction of labeled data to achieve accurate results. Our approach demonstrates impressive performance, achieving over 96.77% accuracy in mosquito image analysis, with minimized both false positives and false negatives. Additionally, the model’s overall accuracy, measured by the area under the ROC curve, surpasses 99.55%, highlighting its robustness and reliability. A notable finding is that fine-tuning with just 10% of labeled data produces results comparable to using the full dataset. This is particularly valuable for resource-limited settings with limited access to advanced equipment and expertise. Our model provides a practical solution for mosquito identification, overcoming the challenges of traditional microscopic methods, such as the time-consuming process and reliance on specialized knowledge in healthcare services. Overall, this model supports personnel in resource-constrained environments by facilitating mosquito vector density analysis and paving the way for future mosquito species identification methodologies.

A Comparison Of Mosquito Species Assemblages Sampled With Three Commonly Used Traps And A Novel Design.

In nuisance or vector mosquito management, effective sampling is a stepping stone to efficient use of resources, targeted control efforts, and successful reduction of disease transmission. Experimental evidence indicates that there are species biases for certain traps, which in turn implies that the traps used will influence the species make-up of samples collected. A comparative study between 3 CO2-baited light traps and 2 hay-infusion baited gravid traps-Centers for Disease Control and Prevention (CDC) light trap, American BioPhysics Company (ABC) light trap, Reiter-Cummings (RC) gravid trap, and a convertible gravid/light trap with a novel design-was conducted to test for species specificity of each trap type. It was found that different species of mosquitoes are more likely to be collected in greater numbers with certain traps compared to others, even between the different light traps or gravid traps. In particular, Coquillettidia perturbans tended to be collected in greater numbers with CDC light traps, Culex salinarius tended to be collected in greater numbers with the experimental convertible light traps, and Culex pipiens tended to be collected in greater numbers with the Reiters-Cummings gravid traps over the other traps included in the study (P ≤ 0.05). The overall species richness of samples was comparable among trap types, with similar performance of the new trap designs as established designs (P ≤ 0.05).

The Mosquitoes (Diptera: Culicidae) of Sonora: Distribution, Ecology, and the First Records of Aedes deserticola Zavortink and Toxorhynchites septentrionalis (Dyar and Knab) in México

The diversity and distribution of mosquitoes from Sonora, Mexico, was documented through entomologic surveys conducted in the four physiographic regions and sub-regions of Sonora: the Sonoran Plain, the Sierra Madre Occidental, the Northern Mountains and Plains, and the Pacific Coastal Plain. Immature stages were collected from aquatic habitats, while adult mosquitoes were collected using Shannon traps, resting in vegetation, and by human landing collections. Overall, 11,316 specimens, which comprised 493 larvae, 224 larval exuviae, 400 pupal exuviae, 33 pupae, 4552 females, 5607 males, and seven male genitalia, were identified. Two subfamilies: Anophelinae and Culicinae, seven tribes, 10 genera, 23 subgenera, and 56 species are reported below. Of these, one tribe, one genus, five subgenera, and 15 species were recorded for the first time in Sonora. Two species, Aedes deserticola Zavortink and Toxorhynchites septentrionalis (Dyar and Knab), are the first recordings of their kind nationwide. Toxorhynchites septentrionalis was also barcoded with the cytochrome oxidase subunit 1 (COI) gene. The presence of Psorophora columbiae (Dyar and Knab) is confirmed in Mexico. Taxonomic notes, new geographic distribution limits of mosquitoes in Sonora, and information regarding their importance as disease vectors are provided. By adding Ae. deserticola and Tx. septentrionalis and confirming Ps. columbiae in Mexico, there are currently 251 mosquito species in the Country.

The effects of seasonal human mobility and Aedes aegypti habitat suitability on Zika virus epidemic severity in Colombia.

The Zika virus epidemic of 2015-16, which caused over 1 million confirmed or suspected human cases in the Caribbean and Latin America, was driven by a combination of movement of infected humans and availability of suitable habitat for mosquito species that are key disease vectors. Both human mobility and mosquito vector abundances vary seasonally, and the goal of our research was to analyze the interacting effects of disease vector densities and human movement across metapopulations on disease transmission intensity and the probability of super-spreader events. Our research uses the novel approach of combining geographical modeling of mosquito presence with network modeling of human mobility to offer a comprehensive simulation environment for Zika virus epidemics that considers a substantial number of spatial and temporal factors compared to the literature. Specifically, we tested the hypotheses that 1) regions with the highest probability of mosquito presence will have more super-spreader events during dry months, when mosquitoes are predicted to be more abundant, 2) regions reliant on tourism industries will have more super-spreader events during wet months, when they are more likely to contribute to network-level pathogen spread due to increased travel. We used the case study of Colombia, a country with a population of about 50 million people, with an annual calendar that can be partitioned into overlapping cycles of wet and dry seasons and peak tourism and off tourism seasons that drive distinct cyclical patterns of mosquito abundance and human movement. Our results show that whether the first infected human was introduced to the network during the wet versus dry season and during the tourism versus off tourism season profoundly affects the severity and trajectory of the epidemic. For example, Zika virus was first detected in Colombia in October of 2015. Had it originated in January, a dry season month with high rates of tourism, it likely could have infected up to 60% more individuals and up to 40% more super-spreader events may have occurred. In addition, popular tourism destinations such as Barranquilla and Cartagena have the highest risk of super-spreader events during the winter, whereas densely populated areas such as Medellín and Bogotá are at higher risk of sustained transmission during dry months in the summer. Our research demonstrates that public health planning and response to vector-borne disease outbreaks requires a thorough understanding of how vector and host patterns vary due to seasonality in environmental conditions and human mobility dynamics. This research also has strong implications for tourism policy and the potential response strategies in case of an emergent epidemic.

Distribution and abundance of Aedes caspius (Pallas, 1771) and Aedes vexans (Meigen, 1830) in the Po Plain (northern Italy).

Knowledge of the distribution and abundance of disease-causing mosquito vectors is fundamental for assessing the risk of disease circulation and introduction. Aedes caspius (Pallas, 1771) and Aedes vexans (Meigen, 1830) have been implicated, to different extents, in the circulation of several arthropod-borne viruses (arboviruses). These two mosquitoes are vectors of Tahyna virus in Europe and are considered potential vectors of Rift Valley fever virus, a virus not present but at risk of introduction on the continent. In this work, we analysed abundance data collected during West Nile virus (WNV) surveillance in northern Italy (Po Plain) via 292 CO2-baited traps to evaluate the distribution and density of these two non-target mosquitoes. We modelled the distribution and abundance of these two mosquito species in the surveyed area using two distinct spatial analysis approaches (geostatistical and machine learning), which yielded congruent results. Both species are more abundant close to the Po River than elsewhere, but Ae. caspius is present in the eastern and western parts of the plain, linked with the occurrence of rice fields and wetlands, while Ae. vexans is observed in the middle area of the plain. Presence and abundance data at the municipality level were obtained and made available through this work. This work demonstrates the importance of maintaining and improving entomological surveillance programs with an adequate sampling effort.

Dengue and chikungunya virus dynamics, identification, and monitoring in wastewater.

Monitoring wastewater is an effective strategy for supporting clinical surveillance for viral infections. Wastewater monitoring, also known as wastewater-based epidemiology (WBE), uses existing wastewater collection networks to obtain a composite sample of a population that can be used to predict disease dynamics in a specific area. Viruses such as dengue and chikungunya are primarily transmitted through the bites of infected Aedes mosquito species. The prevalence of the Aedes mosquito in tropical and subtropical regions makes these diseases a serious threat to public health. Employing wastewater surveillance, monitoring, and regulating the spread of diseases like dengue and chikungunya-notably caused by mosquitoes-has been recommended. However, understanding the dynamics of viral release and its persistence in wastewater is critical for monitoring purposes. Although methods for recovering RNA for some viruses from wastewater have been developed, the same approach does not work equally well for viruses such as dengue and chikungunya due to low levels of viral RNA and susceptibility to degradation. As a result, a tailored approach to recovering these viruses from wastewater is required. This review summarizes viral release from infected hosts, its dynamics, and approaches for dengue and chikungunya wastewater surveillance. The review also identifies existing knowledge gaps in viral persistence in wastewater and recovery.

Environmental determinants of West Nile virus vector abundance at the wildlife-livestock interface.

The diversity and abundance of vectors are essential parameters in the transmission dynamics of West Nile virus (WNV) between its avian reservoirs and clinically susceptible mammalian species. Knowing the determinants of vector abundance could be thus useful in preventing West Nile fever (WNF) cases and associated socio-economic impact. We designed a survey at the wildlife-livestock interface to test the hypothesis that variations in environmental favourability between anthropized and wild scenarios modulate WNV vector abundance and transmission risk. In a continental Mediterranean region where WNF has recently emerged, we selected nine sampling sites and allocated three areas to every site with a decreasing gradient of wildlife-livestock interaction: A1-a horse farm where interaction is maximal; A2-a zone of intermediate interaction 500-1000 m from the farm; and A3-an entirely wild zone of low interaction 1-5 km from the farm. At a fortnightly frequency, we estimated mosquito abundance at each of the 27 study sites in May-December 2018 and April-July 2019. We estimated bird and mammal abundance, collected meteorological information and characterised mosquito habitat at the site scale. Thereafter, we studied the determinants of Culex spp., Culex pipiens sensu lato (s.l.) Linnaeus, 1758 (Diptera: Culicidae) and Culex theileri Theobald, 1903 abundance by constructing negative binomial generalised linear mixed models. We identified 20 mosquito species, with a notable predominance of Culex spp. and, particularly, of Cx. pipiens s.l. We found differences in the spatiotemporal distribution of Culex spp. abundance and confirmed our hypothesis by finding important effects of local environmental variations in abundance. The accumulated rainfall in fortnights 4-14 and the mean temperature of the two fortnights before sampling were positively and statistically significantly associated with the abundance of Cx. pipiens s.l. (Z = 13.09, p < 0.001, and Z = 9.91, p < 0. 001, respectively) and Culex spp. (Z = 13.35, p < 0.001, and Z = 6.99, p < 0.001, respectively), while the mean temperature of the two previous fortnights was a positive statistically significant predictor (Z = 14.69, p < 0.001) of the abundance of Cx. theileri. The farm environment was the most conducive predictor to hosting Culex spp. compared with wild settings. Our results indicate that continental Mediterranean environments are favourable for WNV circulation and maintenance, especially the environment of anthropized rural settings such as farms. These results will have an impact on the spatiotemporal risk prediction of WNF emergence in continental Mediterranean environments.

Temporal Activity and Distribution of the Invasive Mosquitoes Aedes albopictus and Aedes japonicus in the Zagreb Area, Croatia

Aedes albopictus and Aedes japonicus are invasive mosquito species that are causing great public concern. Aedes albopictus have successfully spread in Croatia, established in both the coastal and continental parts of the country, while Aedes japonicus is invading temperate climate areas. The invasive Aedes species are particularly attracted to the black plastic water containers and flower vases in cemeteries where they oviposit their eggs. Therefore, monitoring of this species was carried out in 12 cemeteries in Zagreb, using ovitraps with masonite strips as a substrate for oviposition. The monitoring was carried out from 2017 to 2020. The traps were inspected and the substrate was replaced every two weeks. This study showed that these two invasive species were present and very abundant in the cemeteries. In the case of Ae. albopictus, a higher population density and a greater number of occupied cemeteries were detected. This species was identified in all 12 cemeteries. Aedes albopictus was identified as the dominant species at all study sites. The spread of Ae. japonicus increased during 2018 in comparison to the previous year. Although this species was present in approximately 9% of the ovitraps, the observed population remained consistent throughout the course of the study. The findings indicate that cemeteries can be considered as significant public health hotspots, as the invasive Aedes mosquitoes tend to develop and reproduce in such environments. Consequently, the mosquito population of these two invasive species may only be reduced by applying integrated mosquito management measures, focused on the education of citizens.

DNA Barcoding for the Identification of Adult Mosquitoes (Diptera: Culicidae) in Western Australia.

Precise mosquito identification is integral to effective arbovirus surveillance. Nonetheless, the conventional morphological approach to identifying mosquito species is laborious, demands expertise and presents challenges when specimens are damaged. DNA barcoding offers a promising alternative, surmounting challenges inherent in morphological identification. To integrate DNA barcoding into arbovirus surveillance effectively, a robust dataset of mosquito barcode sequences is required. This study established a comprehensive repository of Cytochrome Oxidase I (COI) barcodes, encompassing 177 samples representing 45 mosquito species from southern and northern Western Australia (WA), including 16 species which have not been previously barcoded. The average intraspecific and interspecific genetic distances were 1% and 6.8%, respectively. Anopheles annulipes sensu lato had the highest intraspecific distance at 9.1%, signifying a genetically diverse species. While validating the potential of COI barcodes to accurately differentiate mosquito species, we identified that some species pairs have low COI divergence. This includes Aedes clelandi and Ae. hesperonotius, Tripteroides atripes and Tp. punctolaeralis and Ae. turneri and Ae. stricklandi. In addition, we observed ambiguity in identification of the members of Culex sitiens subgroup (Cx. annulirostris, Cx. palpalis and Cx. sitiens) and three members of Cx. pipiens complex (Cx. australicus, Cx. globocoxitus, Cx. quinquefasciatus). In summary, despite presenting challenges in the identification of some mosquito species, the COI barcode accurately identified most of the species and generated a valuable resource that will support the WA arbovirus surveillance program and enhance public health intervention strategies for mosquito-borne disease control.

Pathogenicity and sub-lethal activity of orally administered entomopathogenic fungi against two adult mosquito species, Aedes aegypti (Diptera: Culicidae) and Anopheles stephensi (Diptera: Culicidae)

Entomopathogenic fungi (EPF) are known for their efficacy in controlling adult mosquito populations by penetrating through their cuticle. However, the effect of oral administration of EPF on the biological parameters of Aedes aegypti and Anopheles stephensi remains largely unexplored. This study aimed to assess the effect of orally administrated EPF isolates on the survival, feeding behavior, fecundity, fertility, follicle development and host-searching behavior in response to yeast-generated CO2 of Ae. aegypti and An. stephensi. An initial screening of 50 isolates involved exposure of adult Ae. aegypti and An. stephensi by integument inoculation. Subsequently, the entomopathogenic effect of the five highly virulent isolates was confirmed through oral administration revealing Beauveria pseudobassiana 42–51 as a potent mosquito killer. B. pseudobassiana 42–51 was administered orally to evaluate sub-lethal effects. The results showed a 63 % and 43 % reduction in blood feeding of Ae. aegypti and An. stephensi, respectively. Furthermore, a decrease in egg hatching rate was observed, with a reduction of 83% for Ae. aegypti and 74% for An. stephensi on the seventh day following fungal administration, showing decreased hatchability in both species. Poor and abnormal follicle development was observed in both mosquito species. Also, the host-searching behavior was evaluated by attraction to CO2 utilizing a Y-tube olfactometer. A tendency of reduction in the attraction rate towards the odor was observed three days post-fungal administration. These findings underscore the significant impact of oral administration of B. pseudobassiana 42–51 on mosquitoes, highlighting not only its lethal effects but also sub lethal impacts on their biology. Moreover, this fungus may exhibit the potential to simultaneously control both mosquito species and serve as a biocontrol agent for the management of vector-borne diseases.

Field-evolved resistance to neonicotinoids in the mosquito, Anopheles gambiae, is associated with mutations of nicotinic acetylcholine receptor subunits combined with cytochrome P450-mediated detoxification

New insecticides prequalified for malaria control interventions include modulators of nicotinic acetylcholine receptors that act selectively on different subunits leading to variable sensitivity among arthropods. This study aimed to investigate the molecular mechanisms underlying contrasting susceptibility to neonicotinoids observed in wild populations of two mosquito sibling species. Bioassays and a synergist test with piperonyl butoxide revealed that the sister taxa, Anopheles gambiae and An. coluzzii, from Yaounde, Cameroon, both have the potential to develop resistance to acetamiprid through cytochrome P450-mediated detoxification. However, contrary to An. coluzzii, An. gambiae populations are evolving cross-resistance to several active ingredients facilitated by mutations of nicotinic acetylcholine receptors (nAChRs). We sequenced coding regions on the β1 and α6 nAChR subunits where variants associated with resistance to neonicotinoids or to spinosyns have been found in agricultural pests and detected no mutation in An. coluzzii. By contrast, six nucleotide substitutions including an amino acid change in one of the loops that modulate ligand binding and affect sensitivity were present in the resistant species, An. gambiae. Allele frequency distributions were consistent with the spread of beneficial mutations that likely reduce the affinity of An. gambiae nAChRs for synthetic modulators. Our findings provide critical information for the application and resistance management of nAChR modulators in malaria prevention.

Present and future suitability of invasive and urban vectors through an environmentally driven mosquito reproduction number.

Temperature and water availability significantly influence mosquito population dynamics. We have developed a method, integrating experimental data with insights from mosquito and thermal biology, to calculate the basic reproduction number ([Formula: see text]) for urban mosquito species Aedes albopictus and Aedes aegypti. [Formula: see text] represents the number of female mosquitoes produced by one female during her lifespan, indicating suitability for growth. Environmental conditions, including temperature, rainfall and human density, influence [Formula: see text] by altering key mosquito life cycle traits. Validation using data from Spain and Europe confirms the approach's reliability. Our analysis suggests that temperature increases may not uniformly benefit Ae. albopictus proliferation but could boost Ae. aegypti expansion. We suggest using vector [Formula: see text] maps, leveraging climate and environmental data, to predict areas susceptible to invasive mosquito population growth. These maps aid resource allocation for intervention strategies, supporting effective vector surveillance and management efforts.

Sequencing and Analysis of Wolbachia Strains from A and B Supergroups Detected in Sylvatic Mosquitoes from Brazil

Wolbachia are endosymbiotic bacteria that infect a wide range of arthropods and filarial nematodes, often manipulating host reproduction. The efficacy of Wolbachia-based interventions for dengue and chikungunya control has been validated through numerous field studies in recent years. This study aimed to investigate the diversity and prevalence of Wolbachia infections in sylvatic mosquitoes from two locations in Recife, Brazil. Multiple mosquito species were screened for Wolbachia using both target marker gene amplification coupled with Sanger sequencing and whole-genome sequencing (WGS) approaches. Phylogenetic analyses were conducted to classify Wolbachia strains into supergroups and assess their evolutionary relationships. Results revealed the presence of Wolbachia in eleven mosquito species examined, with different infection rates. Both supergroups A and B of Wolbachia strains were identified, with Aedes albopictus showing co-infection by both supergroups through the WGS approach. We also detected indirect evidence of Wolbachia horizontal transmission among mosquitoes and other distant host orders. This study provides valuable insights into the distribution and diversity of Wolbachia in sylvatic mosquitoes from Brazil and adds new important data about Wolbachia detection through target marker gene amplicon coupled with Sanger sequencing and WGS methods, highlighting its complementarity to ascertain the presence of Wolbachia in mosquito samples.

Severe Hemolysis in Glucose 6 Phosphate Dehydrogenase Deficiency Secondary to Dengue Fever

Dengue is a viral fever transmitted by Aedes species of mosquitoes. Globalization has led to worldwide spread of DF including Oman. High incidence of Glucose 6 phosphate deficiency (G6PD) is present in the population, often undiagnosed. We report three patients admitted in tertiary care hospital in Muscat, Oman with Dengue Fever (DF) that later triggered hemolysis. It proved fatal in one case and caused irreversible renal damage requiring dialysis in other. Both DF and G6PD deficiency can cause bleeding. Both need supportive treatment and avoiding incriminating factors. G6PD deficiency with concomitant viral infections have been reported to increase morbidity and mortality. Hemolysis triggered due to DF in G6PD deficient has not be reported in literature. If the clinical course or hemolytic pattern in DF deviates from expected, an associated hemolytic disorder should be considered especially in regions with high prevalence.