Mosquito Species Research Articles

Identifying ecological factors mediating the spread of three invasive mosquito species: citizen science informed prediction

AbstractDue to their potential role in pathogen transmission, invasive mosquitoes pose considerable threats to human and animal health. Several studies have identified the most important ecological drivers mediating the establishment and spread of key mosquito species (e.g., Aedes aegypti, and Ae. albopictus), and made predictions for future distribution. We evaluated the effect of an exhaustive list of environmental predictors on the distribution of three invasive species in Hungary (Ae. albopictus, Ae. japonicus, and Ae. koreicus) by using the same standards for data collection based on citizen science observations. Current distribution maps of these species were generated from a 5-year survey, then were compared with various predictor maps reflecting climate, habitat type, food supply, traffic, and interspecific competition by using a boosted regression trees approach that resulted in a subset of variables with the strongest impact. The best predictor sets were used to predict the probability of occurrence of the focal species for the whole country, and these predictions based on citizen science were evaluated against the results of an independent recent field surveillance. We uncovered species-specific patterns and found that different predictor sets were selected for the three different species, and only predictions for Ae. albopictus could be validated with direct trapping data. Therefore, citizen science informed distribution maps can be used to identify ecological predictors that determine the spread of invasive mosquitoes, and to estimate risk based on the predicted distribution in the case of Ae. albopictus.

MosquitoSong+: A noise-robust deep learning model for mosquito classification from wingbeat sounds.

In order to assess risk of mosquito-vector borne disease and to effectively target and monitor vector control efforts, accurate information about mosquito vector population densities is needed. The traditional and still most common approach to this involves the use of traps along with manual counting and classification of mosquito species, but the costly and labor-intensive nature of this approach limits its widespread use. Numerous previous studies have sought to address this problem by developing machine learning models to automatically identify species and sex of mosquitoes based on their wingbeat sounds. Yet little work has addressed the issue of robust classification in the presence of environmental background noise, which is essential to making the approach practical. In this paper, we propose a new deep learning model, MosquitoSong+, to identify the species and sex of mosquitoes from raw wingbeat sounds so that it is robust to the environmental noise and the relative volume of the mosquito's flight tone. The proposed model extends the existing 1D-CNN model by adjusting its architecture and introducing two data augmentation techniques during model training: noise augmentation and wingbeat volume variation. Experiments show that the new model has very good generalizability, with species classification accuracy above 80% on several wingbeat datasets with various background noise. It also has an accuracy of 93.3% for species and sex classification on wingbeat sounds overlaid with various background noises. These results suggest that the proposed approach may be a practical means to develop classification models that can perform well in the field.

Implementation of an Intelligent Trap for Effective Monitoring and Control of the Aedes aegypti Mosquito.

Aedes aegypti is a mosquito species known for its role in transmitting dengue fever, a viral disease prevalent in tropical and subtropical regions. Recognizable by its white markings and preference for urban habitats, this mosquito breeds in standing water near human dwellings. A promising approach to combat the proliferation of mosquitoes is the use of smart traps, equipped with advanced technologies to attract, capture, and monitor them. The most significant results include 97% accuracy in detecting Aedes aegypti, 100% accuracy in identifying bees, and 90.1% accuracy in classifying butterflies in the laboratory. Field trials successfully validated and identified areas for continued improvement. The integration of technologies such as Internet of Things (IoT), cloud computing, big data, and artificial intelligence has the potential to revolutionize pest control, significantly improving mosquito monitoring and control. The application of machine learning (ML) algorithms and computer vision for the identification and classification of Aedes aegypti is a crucial part of this process. This article proposes the development of a smart trap for selective control of winged insects, combining IoT devices, high-resolution cameras, and advanced ML algorithms for insect detection and classification. The intelligent system features the YOLOv7 algorithm (You Only Look Once v7) that is capable of detecting and counting insects in real time, combined with LoRa/LoRaWan connectivity and IoT system intelligence. This adaptive approach is effective in combating Aedes aegypti mosquitoes in real time.

Nested patterns of commensals and endosymbionts in microbial communities of mosquito vectors

BackgroundMosquitoes serve as vectors for numerous pathogens, posing significant health risks to humans and animals. Understanding the complex interactions within mosquito microbiota is crucial for deciphering vector-pathogen dynamics and developing effective disease management strategies. Here, we investigated the nested patterns of Wolbachia endosymbionts and Escherichia-Shigella within the microbiota of laboratory-reared Culex pipiens f. molestus and Culex quinquefasciatus mosquitoes. We hypothesized that Wolbachia would exhibit a structured pattern reflective of its co-evolved relationship with both mosquito species, while Escherichia-Shigella would display a more dynamic pattern influenced by environmental factors.ResultsOur analysis revealed different microbial compositions between the two mosquito species, although some microorganisms were common to both. Network analysis revealed distinct community structures and interaction patterns for these bacteria in the microbiota of each mosquito species. Escherichia-Shigella appeared prominently within major network modules in both mosquito species, particularly in module P4 of Cx. pipiens f. molestus, interacting with 93 nodes, and in module Q3 of Cx. quinquefasciatus, interacting with 161 nodes, sharing 55 nodes across both species. On the other hand, Wolbachia appeared in disparate modules: module P3 in Cx. pipiens f. molestus and a distinct module with a single additional taxon in Cx. quinquefasciatus, showing species-specific interactions and no shared taxa. Through computer simulations, we evaluated how the removal of Wolbachia or Escherichia-Shigella affects network robustness. In Cx. pipiens f. molestus, removal of Wolbachia led to a decrease in network connectivity, while Escherichia-Shigella removal had a minimal impact. Conversely, in Cx. quinquefasciatus, removal of Escherichia-Shigella resulted in decreased network stability, whereas Wolbachia removal had minimal effect.ConclusionsContrary to our hypothesis, the findings indicate that Wolbachia displays a more dynamic pattern of associations within the microbiota of Culex pipiens f. molestus and Culex quinquefasciatus mosquitoes, than Escherichia-Shigella. The differential effects on network robustness upon Wolbachia or Escherichia-Shigella removal suggest that these bacteria play distinct roles in maintaining community stability within the microbiota of the two mosquito species.

Unveiling the Larvicidal Potential of Golpar (Heracleum persicum Desf. ex Fisch.) Essential Oil and Its Main Constituents on Aedes and Anopheles Mosquito Vectors.

Natural products are thoroughly studied as valuable alternatives to synthetic insecticides. Heracleum persicum Desf. ex Fisch. (Apiaceae), commonly known as Golpar, is an Iranian medicinal plant largely employed as a spice, which has previously revealed insecticidal potential. The chemical composition of H. persicum essential oil (EO) was investigated by GC-MS and was mainly dominated by hexyl butyrate (36.1%) and octyl acetate (23.7%). The EO and its main esters were tested on three mosquito species. Aedes aegypti (L.) larvae were the most sensitive to all tested products. Lethal concentrations (LC50) of 59.09, 53.59, and 47.05 ppm were recorded for the EO, hexyl butyrate, and octyl acetate, respectively. Aedes albopictus (Skuse) and Anopheles gambiae Giles demonstrated comparable sensitivity to the EO, with LC50 values of 102.97 and 97.91 ppm, respectively, whereas the isolated constituents appeared more active on An. gambiae (LC50 of hexyl butyrate and octyl acetate of 70.97 and 60.71 ppm, respectively) with respect to Ae. albopictus (LC50 of hexyl butyrate and octyl acetate of 85.40 and 91.38 ppm, respectively). Low toxicity was registered for both EO and single components against human embryonic kidney (HEK293) cells. Overall, the H. persicum EO, hexyl butyrate, and octyl acetate could be further considered for larvicide development.

Residual Longevity of Recaptured Sterile Mosquitoes as a Tool to Understand Field Performance and Reveal Quality

Invasive mosquito species, such as Aedes albopictus, pose significant threats to both ecosystems and public health due to their role in transmitting diseases, such as dengue, Zika, and chikungunya. The Sterile Insect Technique (SIT) is a promising vector control strategy aimed at reducing mosquito populations by releasing sterile males to mate with wild females and reduce their reproduction rates. In this study, we employed the captive cohort method, which assesses the remaining longevity of randomly caught released individuals, to assess the longevity and frailty dynamics of sterile and non-sterile Ae. albopictus males. Using a mark–release–recapture approach (MRR), we compared the residual lifespan of sterile and non-sterile released males with that of wild, non-sterile males, aiming to understand the frailty dynamics of released males and, therefore, their quality and field performance. Contrary to expectations, our results revealed that released sterile males showed increased longevity compared to non-sterile males. Further, the marking process did not impact the longevity between lab-kept and marked males, suggesting that the marking process does not adversely affect survival under controlled conditions. These findings underscore the importance of optimizing pre-release and mass-rearing practices to enhance the effectiveness of SIT programs. Our study also demonstrates for the first time the use of the captive cohort method for understanding the biological dynamics of sterile mosquito populations in SIT programs, providing valuable insights for improving vector control strategies.

WNV and SLEV coinfection in avian and mosquito hosts: impact on viremia, antibody responses, and vector competence.

West Nile virus (WNV) and St. Louis encephalitis virus (SLEV) are closely related flaviviruses that can cause encephalitis in humans and related diseases in animals. In nature, both are transmitted by Culex, with wild birds, including jays, sparrows, and robins, serving as vertebrate hosts. WNV and SLEV circulate in the same environments and have recently caused concurrent disease outbreaks in humans. The extent that coinfection of mosquitoes or birds may alter transmission dynamics, however, is not well characterized. We therefore sought to determine if coinfection alters infection kinetics and virus levels in birds and infection rates in mosquitoes. Accordingly, American robins (Turdus migratorius), two species of mosquitoes, and vertebrate and invertebrate cells were infected with WNV and/or SLEV to assess how simultaneous exposure may alter infection outcomes. There was variable impact of coinfection in vertebrate cells, with some evidence that SLEV can suppress WNV replication. However, robins had comparable viremia and antibody responses regardless of coinfection. Conversely, in Culex cells and mosquitoes, we saw a minimal impact of simultaneous exposure to both viruses on replication, with comparable infection, dissemination, and transmission rates in singly infected and coinfected mosquitoes. Importantly, while WNV and SLEV levels in coinfected mosquito midguts were positively correlated, we saw no correlation between them in salivary glands and saliva. These results reveal that while coinfection can occur in both avian and mosquito hosts, the viruses minimally impact one another. The potential for coinfection to alter virus population structure or the likelihood of rare genotypes emerging remains unknown.IMPORTANCEWest Nile virus (WNV) and St. Louis encephalitis virus (SLEV) are closely related viruses that are transmitted by the same mosquitoes and infect the same birds in nature. Both viruses circulate in the same regions and have caused concurrent outbreaks in humans. It is possible that mosquitoes, birds, and/or humans could be infected with both WNV and SLEV simultaneously, as has been observed with Zika, chikungunya, and dengue viruses. To study the impact of coinfection, we experimentally infected vertebrate and invertebrate cells, American robins, and two Culex species with WNV and/or SLEV. Robins were efficiently coinfected, with no impact of coinfection on virus levels or immune response. Similarly, in mosquitoes, coinfection did not impact infection rates, and mosquitoes could transmit both WNV and SLEV together. These results reveal that WNV and SLEV coinfection in birds and mosquitoes can occur in nature, which may impact public health and human disease risk.

Gene Sequencing Study of Mitochondrial Cytochrome Oxidase Subunit I (COI) in Aedes aegypti Mosquito

Aedes aegypti is an important vector from the public health point of view. It transmits pathogens of Dengue and various other diseases. Controlling vector populations is key to reducing disease transmission and it is possible by understanding the taxonomic characteristics of the vectors and their genetic analysis helps in the identification of the genetic variations in species of different geographical areas. The main aim of the present study is the screening of the Aedes mosquito genome of local species as genetic studies give some insights into the vaccine for the treatment of the diseases caused by mosquito species. In the present study, the adult Ae. aegypti collected from Suryapet town where Dengue fever is endemic, used for the mitochondrial Cytochrome Oxidase subunit I (COI) gene sequencing using the techniques of polymerase chain reaction, Electrophoretic separation, spectrophotometric analysis, and BLAST. The mitochondrial COI sequence of 583 bps is published in the National Centre for Biotechnology Information (NCBI) with accession number ON413769. The sequence data was matched with the database available in the NCBI to identify variation in the gene as this gene keeps changing in the organisms and may contribute to the species establishing itself in a particular region due to congenial environmental conditions. One match with the protein called haem copper oxidase subunit I. The transmission of different pathogens in different areas can be ascertained by comparing similar sequence studies documented. Genomic studies involving genetic markers are of immense help in developing the vaccine. The mitochondrial COI gene is the marker often used for evolutionary research. The single nucleotide polymorphisms (SNP) or Restricted fragment length polymorphisms (RFLPs) that occur in DNA also contribute to the vector's adaptability to the different geographical areas and also the survival benefit which are the basis for understanding the vectors thoroughly and their role in disease transmission.

Coexistence and food sources of adult mosquitoes (Diptera: Culicidae) in a rural health center in Piura, Peru 2024.

Motivation for the study. Rural health facilities could be potential foci of transmission and scenarios of zoonosis during epidemic outbreaks of dengue and other arbovirosis due to the coexistence of mosquito species that feed on different vertebrates. Main findings. Aedes aegypti feeds on Homo sapiens sapiens. Culex quinquefasciatus feeds on Homo sapiens sapiens and Canis familiaris. Both coexist in health care areas of the Querecotillo health center. Implications. Molecular techniques should be integrated into vector control to understand feeding patterns in natural conditions and information on probable reservoirs. This study aimed to determine the coexistence and food sources of adult mosquitoes (Diptera: Culicidae) in a rural health center in Piura, Peru by using a descriptive cross-sectional design. Entomological techniques were used to capture and identify mosquitoes, and molecular biotechnology techniques were used to identify food sources. A total of 793 specimens of the Culex and Aedes genera were found coexisting, 789 (99.5%) were Culex quinquefasciatus, 607 (76.9%) were males and 182 (23.1%) were females. Likewise, 4 (100%) corresponded to Aedes aegypti females. The food sources of Aedes aegypti were Homo sapiens sapiens, and Homo sapiens sapiens and Canis familiaris were the food sources of Culex quinquefasciatus. This study provides evidence that rural health centers could be acting as foci of arbovirosis, with the risk that people who come for different ailments could contract diseases transmitted by C. quinquefasciatus and A. aegypti.

A 3D printed device for vibration-assisted separation of different-stage mosquito larvae

Mosquitoes, as major vectors of dangerous diseases, demand effective control measures for public health. Larvicides, while offering a potential solution, can exhibit varying effects on different mosquito species and developmental stages during efficacy studies. Standardizing mosquito developmental stages and ensuring optimal, synchronized development rates of various larval stages are crucial for larvicidal experiments and maximizing pupal production. Manual separation of different stages of larvae is labor intensive, time consuming and error prone. Therefore, this study aimed to investigate the use of a stereolithography 3D-printed device for the separation of mosquito larvae. This device is designed to have three modules to collect different larval stages based on their radial size differences. Each module of the device was equipped with small vibration motors to enable vibration-assisted filtration to prevent clogging. The accuracy of the larvae separation device was studied by repeated experiments and collected samples were analyzed under an optical microscope. The 3D-printed device was demonstrated to be orders of magnitude faster and more accurate compared to manual separation process. A larvicidal bioassay was also designed to investigate larvicidal assay impact on the survival of collected L3 and L4 specimens. Overall, it was shown that the presented device carries an important potential for rapid and accurate separation of different size larvae for larvicidal studies.

Asaia spp. accelerate development of the yellow fever mosquito, Aedes aegypti, via interactions with the vertically transmitted larval microbiome.

A wide range of vector control programmes rely on the efficient production and release of male mosquito. Asaia bacteria are described as potential symbionts of several mosquito species but their relationship with Aedes aegypti has never been rigorously tested. Here, we aimed to quantify the benefits of three Asaia species on host development in Ae. aegypti, and the ability of these bacteria to form a stable symbiotic association with growing larvae. In order to disentangle direct and indirect effects of Asaia inoculation on host development, experiments used insects with an intact microbiome and those reared in near-aseptic conditions, while we characterized bacterial communities and Asaia densities with culture dependent and independent methods (16S rRNA amplicon sequencing). Neonate larvae were inoculated with Asaia spp. for 24 h, or left as uninoculated controls, all were reared on sterile food. Aseptic larvae were produced by surface sterilization of eggs. Although all Asaia were transient members of the gut community, two species accelerated larval development relative to controls. The two mutualistic species had lasting impacts on the larval microbiome, largely by altering the relative abundance of dominant bacteria, namely Klebsiella and Pseudomonas. Axenic larvae were dominated by Asaia when inoculated with this species but showed slower development than conventionally reared insects, indicating that Asaia alone could not restore normal development. Our results reveal Asaia as a poor mutualist for Ae. aegypti, but with a species-specific positive effect on improving host performance mediated by interactions with other bacteria.

Morphological Characterization of Culex Quinquefasciatus (Diptera: Culicidae) Pupae in the Eastern Province of Saudi Arabia.

Over the last 30 years, several mosquito-borne diseases have spread worldwide, threatening human and animal health, including lymphatic filariasis. Lymphatic filariasis is a major public health issue in tropical regions like Saudi Arabia, caused by parasitic worms. The parasitic worms Wuchereria bancrofti and Brugia malayi are transmitted by Culex quinquefasciatus. Cx. quinquefasciatus is a potential vector for various arboviruses like encephalitis virus and West Nile virus, along with protozoa like Plasmodium relictum that cause bird malaria. With the increasing number of mosquito species, there is an increased need for additional species identification. More attention is being directed to the immature stage, specifically the pupae, due to their valuable characteristics for species identification. Cx. quinquefaciatus, one of the nine Culicine species found in Saudi Arabia, lacks a complete description of its pupal stage and only has partial descriptions of other developmental stages, making identification challenging. This study aimed to investigate the morphological characteristics of Cx. quinquefaciatus pupae, focusing on the cephalothorax, trumpet, abdomen, paddle, and genital lobes, as well as the distribution and arrangement of setal branching and chaetotaxy. The pupae were collected from Qaryat Al Ulya Governorate, Eastern region, KSA, and maintained in a Biology Laboratory at the University of Hafr Al Batin from September to October 2022. The findings of this study have provided the essential characteristics regarding the distinguishing features of Cx. quinquefaciatus pupae to distinguish it from other closely related species. This identification could assist field entomologists in enhancing their efficiency by classifying mosquitoes during virus outbreaks.

Continuous and Dynamic Circulation of West Nile Virus in Mosquito Populations in Bucharest Area, Romania, 2017-2023.

West Nile virus (WNV) is a mosquito-borne pathogen with a worldwide distribution. Climate change and human activities have driven the expansion of WNV into new territories in Europe during the last two decades. Romania is endemic for WNV circulation since at least 1996 when the presence of lineage 1 was documented during an unprecedented outbreak. Lineage 2 was first identified in this country during a second significant human outbreak in 2010. Its continuous circulation is marked by clade replacement, and even co-circulation of different strains of the same clade was observed until 2016. The present study aims to fill the information gap regarding the WNV strains that were circulating in Romania between 2017 and 2023, providing chiefly viral sequences obtained from mosquito samples collected in the Bucharest metropolitan area, complemented by human and bird viral sequences. WNV was detected mainly in Culex pipiens mosquitoes, the vectors of this virus in the region, but also in the invasive Aedes albopictus mosquito species. Lineage 2 WNV was identified in mosquito samples collected between 2017 and 2023, as well as in human sera from patients in southern and central Romania during the outbreaks of 2017 and 2018. Both 2a and 2b sub-lineages were identified, with evidence of multiple clusters and sub-clusters within sub-lineage 2a, highlighting the complex and dynamic circulation of WNV in Romania, as a consequence of distinct introduction events from neighboring countries followed by in situ evolution.

Chromosomal Polymorphism of Malaria Mosquitoes of Karelia and Expansion of Northern Boundaries of Species Areas

Chromosomal variability in peripheral populations of malaria mosquitoes of the genus Anopheles (Diptera, Culicidae) inhabiting the territory of Karelia was studied. The modern northern limits of the ranges of sibling species of malarial mosquitoes An. beklemishevi, An. daciae, An. messeae s. s. and An. maculipennis were established. After 2010, the distribution boundary of malaria mosquitoes shifted northward by 170 km, from the 65th parallel to the Arctic Circle. Inversion heterozygotes XL1, XL2, 2R2, 3R1 and 3R5 were found in peripheral populations of An. beklemishevi. Peripheral populations of An. messeae s. s. were homozygous for inversion of sex chromosome XL1 and differed in the frequencies of autosome inversions from the middle taiga populations. The frequency of heterozygotes for autosomal inversions 2R1, 3R1, and 3L1 increased in populations at the edge of the species area. Chromosomal variability in peripheral populations contributes to the dispersal of malaria mosquitoes in high latitudes under warming climate conditions.

Mosquito Species Composition in Nasarawa Local Government Area, Nasarawa State, Nigeria

Study’s Excerpt The resting densities, biting rates, and indoor mosquito populations in Nasarawa LGA were assessed. Prokopack aspirator is applied for morning mosquito collection and the dissecting microscope for identification of species-specific attributes. The results highlight critical areas for targeted vector control to mitigate malaria transmission in the region. Full Abstract Numerous mosquito species are capable of carrying various tropical diseases. This study ascertained the composition of mosquitoes in Nasarawa Local Government Area, Nasarawa State, Central Nigeria. Adult mosquitoes were collected between 0600 and 0900 hours in the morning using a battery-operated Prokopack aspirator. The mosquitoes were then placed in a petri dish with proper labelling and taken to a laboratory for identification and dissection. Using a dissecting microscope and identification key, mosquitoes were sorted and morphologically classified according to their morphological features. The mosquito midgut was dissected to check for sporozoites infectivity. The man-biting rate (MBR) and indoor resting density (IRD) were computed. A total of 314 adult mosquitoes, spanning four species and belonging to the Anopheline and Culicine mosquito groups, were found to be resting indoors with An. gambiae representing 39.2% of the total composition. A significant difference in mosquito abundance (χ2= 58.866, df = 3, P=0.001) was observed between the four species that were reported. There is no discernible variation in the mosquito composition in the research region (χ2= 4.861, df = 2, P = 0.088). A statistically significant variance in sex was noted (χ2=285.235, df = 2, P = 0.000). The biting rate was recorded at 2.6 bites per person per night, and an indoor resting density of 5.23 mosquitoes per room per night was recorded. There was a noteworthy distinction in the abdomen condition of the mosquitoes (χ2 = 45.564, df = 3, p < 0.001). Mosquito species abundance in October was 200 (63.7%), compared to 114 (36.3) in September. Nonetheless, a noteworthy distinction was observed in the abundance of mosquito species throughout the research months (χ2= 7.5076, df = 1, P-value = 0.006). Based on the study's findings that provided insight into the species composition of the mosquito population in the study area, it is recommended to remove possible breeding grounds, promote the use of insecticide-treated nets, and prioritize interrupting vector-human contact as a means of halting the spread of malaria parasites.

Seasonal insights for integrative mosquito management from multi-year baseline entomological data on Aedes aegypti in Lee County, Florida.

The spread of arboviruses like yellow fever, dengue, chikungunya, and Zika, transmitted by the invasive mosquito Aedes aegypti has led to the development of many strategies to suppress mosquito populations. Given the rapid development of resistance to common chemical larvicides and adulticides in some Ae. aegypti populations, as well as the ever-shrinking chemical options for mosquito control, there is a pressing need for new tools and deployment of those innovative tools as a component of integrative mosquito management programs. Prior to the adoption of any mosquito population intervention, be it conventional or innovative, understanding the baseline population is essential to evaluate the efficacy of the control measure. The Lee County Mosquito Control District in Florida has collected a three-year-long period of baseline entomological surveillance data collection for Ae. aegypti on Captiva and Sanibel Islands as foundational information prior to implementation of a new integrative mosquito management approach. We identified 18 mosquito species and described their population dynamics during the rainy and dry seasons. The two islands had no significant differences in species richness, diversity, dominance, or evenness overall. Yet, there were clear differences between the high rain season and low rain season in the Shannon diversity index, Simpson dominance index, and Pielou species evenness index within each site. Our data suggest that any innovative intervention should begin before mid to late April when the mosquito population is at its lowest and certainly before populations build up to their summer peak between June and September. These data also show the spatial distribution of Ae. aegypti is dynamic in space and time, identifying hotspots of mosquito abundance to focus on for future interventions. Overall, our study emphasizes the importance of entomological data collection to understand the population dynamics of Ae. aegypti mosquitoes, including the impact of environmental factors such as temperature and precipitation.

Innovative Approaches to Mosquito Control: A Comprehensive Review on Beneficial Bacteria

Mosquito bites spread many deadly diseases like dengue, chikungunya, zika virus, malaria etc. The spread of these diseases can be controlled by checking the mosquito population. Bacterial control is an effective way to kill mosquitoes without harming non-target organisms. The review discusses the role of bacteria in mosquito control. Several useful bacteria involved in mosquito control such as E. coli, Streptococcus, Pseudomonas, Bacillus and Enterococcus that effectively kill the mosquitoes by producing insecticidal proteins such as endotoxins, Bin and Mtx proteins that specifically bind only with targeted mosquito species and kill them. Bacteria belongs to genus Bacillus found most effective against mosquito larvae such as Bacillus thuringiensis israelensis and Bacillus sphaericus, which produces endotoxins, selectively target mosquito larvae. When these toxins are consumed by larvae, these endotoxins disrupt the cells of midgut of larvae, which kills them before they can develop into adult mosquitoes. This selective and ecologically benign strategy minimizes damage to creatures that are not its intended targets. The environmental safety and specificity of bacterial control methods make them more sustainable and effective as compared to chemical control of mosquitoes population. This approach is more selective and more sustainable since it minimizes the impact on the environment and reduces the likelihood that resistance would develop. In this review we are presenting about the bacterial world and their interactions with mosquitoes, parasites, nematodes etc. and how they prevent disease transmission.

Towards transforming malaria vector surveillance using VectorBrain: a novel convolutional neural network for mosquito species, sex, and abdomen status identifications

Malaria is a major public health concern, causing significant morbidity and mortality globally. Monitoring the local population density and diversity of the vectors transmitting malaria is critical to implementing targeted control strategies. However, the current manual identification of mosquitoes is a time-consuming and intensive task, posing challenges in low-resource areas like sub-Saharan Africa; in addition, existing automated identification methods lack scalability, mobile deployability, and field-test validity. To address these bottlenecks, a mosquito image database with fresh wild-caught specimens using basic smartphones is introduced, and we present a novel CNN-based architecture, VectorBrain, designed for identifying the species, sex, and abdomen status of a mosquito concurrently while being efficient and lightweight in computation and size. Overall, our proposed approach achieves 94.44±2% accuracy with a macro-averaged F1 score of 94.10±2% for the species classification, 97.66±1% accuracy with a macro-averaged F1 score of 96.17±1% for the sex classification, and 82.20±3.1% accuracy with a macro-averaged F1 score of 81.17±3% for the abdominal status classification. VectorBrain running on local mobile devices, paired with a low-cost handheld imaging tool, is promising in transforming the mosquito vector surveillance programs by reducing the burden of expertise required and facilitating timely response based on accurate monitoring.

AEDEOMYIA SQUAMIPENNIS: A NEW GENUS AND SPECIES RECORD FOR COLLIER COUNTY, FLORIDA, USA

ABSTRACT On November 7, 2023, 3 female specimens of Aedeomyia squamipennis were captured in Collier County, Florida, for the first time during routine adult mosquito surveillance in Collier Seminole State Park. This species was first found in the USA in Miami-Dade County in 2016 and has since expanded into multiple counties throughout South Florida. The presence of Ad. squamipennis has implications for arbovirus transmission as it is a vector for the Venezuelan equine encephalitis virus group. The detection of this mosquito species also highlights the importance of a robust and consistent mosquito surveillance program.

Functional characterization of CCHamides and deorphanization of their receptors in the yellow fever mosquito, Aedes aegypti

As a widely distributed anthropophilic mosquito species and vector of various arboviruses, Aedes aegypti poses a significant threat to human health on a global scale. Investigating mosquito neuropeptides allows us to better understand their physiology. The neuropeptides CCHamide1 (CCHa1) and CCHamide2 (CCHa2) along with their associated G protein-coupled receptors (CCHa1R and CCHa2R) were recently identified and studied across insects. However, expression profiles and physiological roles of CCHamides and their receptors in many other insects, including A. aegypti, remain unclear. This research aimed to quantify and localize the expression of CCHamides along with their receptors and gain insight on their physiological function in the yellow fever mosquito. RT-qPCR analysis revealed transcript abundance of CCHamides and receptors changes over development. Differential expression was also observed in tissues/organs of adult mosquitoes indicating CCHa1 and CCHa2 transcripts are enriched in the midgut, while receptors are expressed across various tissues. CCHamide immunoreactivity was observed in neurons in the brain and ventral nerve cord along with enteroendocrine cells in the posterior midgut adjacent to the midgut-hindgut junction, corroborating their transcript expression profiles. Using different mass spectrometrical approaches, presence of CCHamides were confirmed in the brain of both sexes, including the pars intercerebralis of female mosquitoes, as well as in the gut of adult mosquitoes. For chemical identification of predicted CCHamides, we analyzed brain and gut extracts by ESI-Q Exactive Orbitrap MS and resulting fragmentations confirmed CCHa1 and CCHa2 in brain and midgut samples of both male and female mosquitoes. A heterologous functional assay was used to confirm the specificity and sensitivity of the two CCHamide receptors by assessing their activation in response to diverse mosquito peptides, which confirmed CCHa1 and CCHa2 as natural ligands. Finally, using a capillary feeder (CAFE) bioassay, our results suggest that CCHa2 modulates feeding behaviour in female mosquitoes.