[First detection of Rift Valley Fever Virus among Culex pipiens in Tahoua, Niger]. / Détection du virus de la fièvre de la vallée du Rift chez Culex pipiens à Tahoua au Niger.

Background: The Rift Valley Fever (RVF) is an arbovirus disease responsible of regular epizootics and epidemics in sub-Saharan Africa and Arabian Peninsula. In 2016, Niger experienced its first outbreak of RVF in Tahoua region, which resulted in high consequences in animal and human health. The aim of this study was to investigate on the RVFV circulation among potential vectors of the disease. Methods: This was a cross-sectional survey carried out in Tahoua and Agadez regions in August 2021. Adult mosquitoes were collected by using the morning spray in human dwellings and the CDC light trap methods. After morphological identification, viral RNA was extracted. The RNA was extracted by using QIAamp Viral RNA Mini Kit (Qiagen). The RVFV detection was performed by using the qRT-PCR method. Results: A total of 2487 insects (1978 mosquitoes, 509 sandflies and 251 biting midges) were identified and divided into three families (Culicidae, Psychodidae and Ceratopogonidae). The Culicidae family composed of the Culex genus being the most abundant with a predominance of Cx.pipiens (31.88%; n = 793) followed by Mansonia sp (21.51%; n = 535), Anophelesgambiae s.l. (8.44%; n = 210), An. pharoensis (0.72%; n = 18), An. rufipes (0.48%; n = 12), Cx. quinquefasciatus (6.39%; n = 159), the Psychodidae with sandflies (20.46%; n = 509), and the Ceratopogonidae with Culicoides genus (10.09%; n = 251). The qRT-PCR carried out on a sample of mosquitoes (N = 96) highlighted that one individual of Cx.pipiens was found positive to RVFV. This specimen was from Tassara locality (Tahoua) and collected by CDC Light Trap method. Conclusion: This study reveals for the first time the circulation of RVFV among Cx.pipiens in Niger and highlights the possible vectorial role of this vector in the disease transmission. Further investigations should be carried out to identify the biological and ecological determinants that support the maintenance of the virus in this area in order to guide control interventions.

Synthesis, molecular modelling and evaluation of larvicidal efficacy of annulated Benzo[h]chromenes against Culex pipiens L. Larvae.

A new series of substituted benzo[h]chromene, benzochromenopyrimidine, and benzochromenotriazolopyrimidine derivatives were synthesized via chemical transformations of iminonitrile, ethoxymethylene amino, and cyanomethylene functionalities. The chemical structures of the synthesized compounds were assured by spectroscopic data and elemental analysis. The larvicidal efficacy of these compounds against Culex pipiens L. larvae was investigated, revealing potent insecticidal activity, particularly for compounds 6, 10, and 16, exceeding that of the standard insecticide chlorpyrifos. The mode of action of these compounds was explored through molecular docking studies, indicating their potential as acetylcholine esterase (AChE) inhibitors and nicotinic acetylcholine receptors (nAChR) blockers. The structure-activity relationship analysis highlighted the influence of substituents and fused heterocyclic rings on larvicidal potency. These findings suggest that the synthesized compounds hold promise as potential candidates for developing novel and effective mosquito control agents.

Extreme resistance to S-methoprene in field-collected Culex pipiens (Diptera: Culicidae) across the Chicago, IL region.

Insect growth regulators, like S-methoprene, are heavily relied upon worldwide for larval mosquito chemical control due to their target specificity and long-lasting effects. In this study, susceptibility to S-methoprene was evaluated in Culex pipiens, a globally important vector species. Populations from 14 sites throughout the Chicago area with a long history of S-methoprene use and two sites with minimal use in Wisconsin were examined. Using a bioassay methodology and probit analyses, LC50 and LC90 values were calculated and compared to a susceptible laboratory strain to develop resistance ratios, then categorized for resistance intensity. The resistance ratios observed required the addition of another category, termed 'extreme' resistance, indicating resistance ratios greater than 100. 'Low' to 'extreme' levels of resistance to S-methoprene were detected throughout Illinois populations, with resistance ratios ranging from 2.33 to 1010.52. Resistance was not detected in populations where S-methoprene pressure has been very limited. These 'extreme' resistance ratios observed have never been documented in a wild vector species mosquito population. The relationships between historical S-methoprene use, resistance detected with laboratory bioassays, and the potential for field product failure remain unclear. However, the profound resistance detected here demonstrates a potential critical threat to protecting public health from mosquito-borne diseases.

Population genetic structure of Culex tritaeniorhynchus in different types of climatic zones in China.

BACKGROUND: Culex tritaeniorhynchus is widely distributed in China, from Hainan Island in the south to Heilongjiang in the north, covering tropical, subtropical, and temperate climate zones. Culex tritaeniorhynchus carries 19 types of arboviruses. It is the main vector of the Japanese encephalitis virus (JEV), posing a serious threat to human health. Understanding the effects of environmental factors on Culex tritaeniorhynchus can provide important insights into its population structure or isolation patterns, which is currently unclear. RESULTS: In total, 138 COI haplotypes were detected in the 552 amplified sequences, and the haplotype diversity (Hd) value increased from temperate (0.534) to tropical (0.979) regions. The haplotype phylogeny analysis revealed that the haplotypes were divided into two high-support evolutionary branches. Temperate populations were predominantly distributed in evolutionary branch II, showing some genetic isolation from tropical/subtropical populations and less gene flow between groups. The neutral test results of HNQH (Qionghai) and HNHK(Haikou) populations were negative (P < 0.05), indicating many low-frequency mutations in the populations and that the populations might be in the process of expansion. Moreover, Wolbachia infection was detected only in SDJN (Jining) (2.24%), and all Wolbachia genotypes belonged to supergroup B. To understand the influence of environmental factors on mosquito-borne viruses, we examined the prevalence of Culex tritaeniorhynchus infection in three ecological environments in Shandong Province. We discovered that the incidence of JEV infection was notably greater in Culex tritaeniorhynchus from lotus ponds compared to those from irrigation canal regions. In this study, the overall JEV infection rate was 15.27 per 1000, suggesting the current risk of Japanese encephalitis outbreaks in Shandong Province. CONCLUSIONS: Tropical and subtropical populations of Culex tritaeniorhynchus showed higher genetic diversity and those climatic conditions provide great advantages for the establishment and expansion of Culex tritaeniorhynchus. There are differences in JEV infection rates in wild populations of Culex tritaeniorhynchus under different ecological conditions. Our results suggest a complex interplay of genetic differentiation, population structure, and environmental factors in shaping the dynamics of Culex tritaeniorhynchus. The low prevalence of Wolbachia in wild populations may reflect the recent presence of Wolbachia invasion in Culex tritaeniorhynchus.

Application of circular statistics in temporal distribution of adult mosquitoes in Qingdao, Shandong Province, China, 2021-2023.

BACKGROUND: Analyses of the temporal distribution of mosquitoes are presented in statistical charts, but it is difficult to prove in statistics whether differences in peak periods exist among different years or habitats. This study aimed to investigate the application of circular statistics in determining the peak period and a comparison of differences. METHODS: Surveillance of adult mosquitoes was conducted twice a month by light traps in five different habitats from March to November for 3 years (2021-2023) in Qingdao, Shandong Province, China. The Kruskal-Wallis test was performed to determine the differences in mosquito density among different years and habitats. Circular statistics and line charts were employed to determine the peak period and a comparison of differences. RESULTS: Among a total of 14,834 adult mosquitoes comprising five mosquito species from four genera, Culex pipiens pallens was dominant and accounted for 89.6% of the specimens identified. Aedes albopictus, Armigeres subalbatus, and Anopheles sinensis made up 5.7%, 4.2%, and 0.5%, respectively. Culex tritaeniorhynchus accounted for less than 0.1%. The mean mosquito density (females/trap night) for the trapping period was 10.3 in 2021, 5.6 in 2022, and 3.6 in 2023. Among five habitats, the highest mosquito density was 8.9 in livestock sheds, followed by 6.8 in parks, 5.9 in rural dwellings, 5.5 in urban dwellings, and 5.4 in hospitals. No statistically significant differences were found among different years (H = 1.96, d.f. 2, P = 0.376) and habitats (H = 0.45, d.f. 4, P = 0.978). Overall, the peak period of mosquito activity fell in the months from June to September. The peak period among 3 years differed significantly (F(2,7022) = 119.17, P < 0.01), but there were no statistically significant differences in peak period among different habitats (F(4,7020) = -159.09, P > 0.05). CONCLUSION: Circular statistics could be effectively combined with statistical charts to elucidate the peak period of mosquitoes and determine the differences in statistics among different years and habitats. These findings will provide valuable information for mosquito control and public health management.

Upscaling the production of sterile male mosquitoes with an automated pupa sex sorter.

Effective mosquito population suppression has been repeatedly demonstrated in field trials through the release of male mosquitoes to induce sterile mating with wild females using the incompatible insect technique (IIT), the sterile insect technique (SIT), or their combination. However, upscaling these techniques requires a highly efficient and scalable approach for the sex separation of mass-reared mosquitoes to minimize the unintentional release of females, which can lead to either population replacement or biting nuisance, a major bottleneck up to now. Here, we report the successful development of an automated mosquito pupa sex sorter that can effectively separate large numbers of males from females for population suppression of Aedes aegypti, A. albopictus, and Culex quinquefasciatus. The male production capacity of the automated sex sorter was increased by ~17-fold compared with manual sex separation with the Fay-Morlan sorter and enabled one person to separate 16 million males per week. With ~0.5% female contamination, the produced males exhibited high flight ability and mating performance. The field trial demonstrates that the quality of A. albopictus males produced using the automated sex sorter is suitable for inducing population suppression. These results indicate that the automated sex sorter offers the potential to upscale IIT and SIT against mosquito vectors for disease control.

Culex-Transmitted Diseases: Mechanisms, Impact, and Future Control Strategies using Wolbachia.

Mosquitoes of the Culex genus are responsible for a large burden of zoonotic virus transmission globally. Collectively, they play a significant role in the transmission of medically significant diseases such as Japanese encephalitis virus and West Nile virus. Climate change, global trade, habitat transformation and increased urbanisation are leading to the establishment of Culex mosquitoes in new geographical regions. These novel mosquito incursions are intensifying concerns about the emergence of Culex-transmitted diseases and outbreaks in previously unaffected areas. New mosquito control methods are currently being developed and deployed globally. Understanding the complex interaction between pathogens and mosquitoes is essential for developing new control strategies for Culex species mosquitoes. This article reviews the role of Culex mosquitos as vectors of zoonotic disease, discussing the transmission of viruses across different species, and the potential use of Wolbachia technologies to control disease spread. By leveraging the insights gained from recent successful field trials of Wolbachia against Aedes-borne diseases, we comprehensively discuss the feasibility of using this technique to control Culex mosquitoes and the potential for the development of next generational Wolbachia-based control methods.

Study on the temporal and spatial distribution of Culex mosquitoes in Hanoi, Vietnam.

Arboviruses transmitted by mosquitoes, including Japanese encephalitis virus (JEV), present a substantial global health threat. JEV is transmitted by mosquitoes in the genus Culex, which are common in both urban and rural areas in Vietnam. In 2020, we conducted a 1-year survey of Culex mosquito abundance in urban, suburban, and peri-urban areas of Hanoi using CDC-light traps. Mosquitoes were identified to species and sorted into pools based on species, sex, and trap location. The mosquito pools were also investigated by RT-qPCR for detection of JEV. In total, 4829 mosquitoes were collected over a total of 455 trap-nights, across 13 months. Collected mosquitoes included Culex, Aedes, Anopheles, and Mansonia species. Culex mosquitoes, primarily Cx. quinquefasciatus, predominated, especially in peri-urban areas. Most Culex mosquitoes were caught in the early months of the year. The distribution and abundance of mosquitoes exhibited variations across urban, suburban, and peri-urban sites, emphasizing the influence of environmental factors such as degree of urbanization, temperature and humidity on Culex abundance. No JEV was detected in the mosquito pools. This study establishes baseline knowledge of Culex abundance and temporal variation, which is crucial for understanding the potential for JEV transmission in Hanoi.

Synthesis, insecticidal Activity, and molecular docking analysis of some benzo[h]quinoline derivatives against Culex pipiens L. Larvae.

Some heterocycles bearing a benzo[h]quinoline moiety were synthesized through treating a 3-((2-chlorobenzo[h]quinolin-3-yl)methylene)-5-(p-tolyl)furan-2(3H)-one with four nitrogen nucleophiles comprising ammonium acetate, benzylamine, dodecan-1-amine, and 1,2-diaminoethane. Also, thiation reactions of furanone and pyrrolinone derivatives were investigated. The insecticidal activity of these compounds against mosquito larvae (Culex pipiens L.) was evaluated. All tested compounds exhibited significant larvicidal activity, surpassing that of the conventional insecticide chlorpyrifos. In silico docking analysis revealed that these compounds may act as acetyl cholinesterase (AChE) inhibitors, potentially explaining their larvicidal effect. Additionally, interactions with other neuroreceptors, such as nicotinic acetylcholine receptor and sodium channel voltage-gated alpha subunit were also predicted. The results obtained from this study reflected the potential of benzo[h]quinoline derivatives as promising candidates for developing more effective and sustainable mosquito control strategies. The ADME (absorption, distribution, metabolism, and excretion) analyses displayed their desirable drug-likeness and oral bioavailability properties.

An amplicon-based sequencing approach for Usutu virus characterization.

Usutu virus (USUV), an arbovirus from the Flaviviridae family, genus Flavivirus, has recently gained increasing attention because of its potential for emergence. After his discovery in South Africa, USUV spread to other African countries, then emerged in Europe where it was responsible for epizootics. The virus has recently been found in Asia. USUV infection in humans is considered to be most often asymptomatic or to cause mild clinical signs. However, a few cases of neurological complications such as encephalitis or meningo-encephalitis have been reported in both immunocompromised and immunocompetent patients. USUV natural life cycle involves Culex mosquitoes as its main vector, and multiple bird species as natural viral reservoirs or amplifying hosts, humans and horses can be incidental hosts. Phylogenetic studies carried out showed eight lineages, showing an increasing genetic diversity for USUV. This work describes the development and validation of a novel whole-genome amplicon-based sequencing approach to Usutu virus. This study was carried out on different strains from Senegal and Italy. The new approach showed good coverage using samples derived from several vertebrate hosts and may be valuable for Usutu virus genomic surveillance to better understand the dynamics of evolution and transmission of the virus.

Community end user perceptions of hessian fabric transfluthrin vapour emanators for protecting against mosquitoes under conditions of routine use in Port-au-Prince, Haiti.

BACKGROUND: A treated fabric device for emanating the volatile pyrethroid transfluthrin was recently developed in Tanzania that protected against night-biting Anopheles and Culex mosquitoes for several months. Here perceptions of community end users provided with such transfluthrin emanators, primarily intended to protect them against day-active Aedes vectors of human arboviruses that often attack people outdoors, were assessed in Port-au-Prince, Haiti. METHODS: Following the distribution of transfluthrin emanators to participating households in poor-to-middle class urban neighbourhoods, questionnaire surveys and in-depth interviews of end-user households were supplemented with conventional and Photovoice-based focus group discussions. Observations were assessed synthetically to evaluate user perceptions of protection and acceptability, and to solicit advice for improving and promoting them in the future. RESULTS: Many participants viewed emanators positively and several outlined various advantages over current alternatives, although some expressed concerns about smell, health hazards, bulkiness, unattractiveness and future cost. Most participants expressed moderate to high satisfaction with protection against mosquitoes, especially indoors. Protection against other arthropod pests was also commonly reported, although satisfaction levels were highly variable. Diverse use practices were reported, some of which probably targeted nocturnal Culex resting indoors, rather than Aedes attacking them outdoors during daylight hours. Perceived durability of protection varied: While many participants noted some slow loss over months, others noted rapid decline within days. A few participants specifically attributed efficacy loss to outdoor use and exposure to wind or moisture. Many expressed stringent expectations of satisfactory protection levels, with even a single mosquito bite considered unsatisfactory. Some participants considered emanators superior to fans, bedsheets, sprays and coils, but it is concerning that several preferred them to bed nets and consequently stopped using the latter. CONCLUSIONS: The perspectives shared by Haitian end-users are consistent with those from similar studies in Brazil and recent epidemiological evidence from Peru that other transfluthrin emanator products can protect against arbovirus infection. While these encouraging sociological observations contrast starkly with evidence of essentially negligible effects upon Aedes landing rates from parallel entomological assessments across Haiti, Tanzania, Brazil and Peru, no other reason to doubt the generally encouraging views expressed herein by Haitian end users could be identified.

Disclosing the virome of Aedes, Anopheles and Culex female mosquitoes, Alto Pantanal of Mato Grosso, Brazil, 2019.

Using Illumina NextSeq sequencing and bioinformatics, we identified and characterized thirty-three viral sequences of unsegmented and multipartite viral families in Aedes spp., Culex sp. and Anopheles darlingi female mosquito pools from Porto São Luiz and Pirizal, Alto Pantanal. Seventeen sequences belong to unsegmented viral families, twelve represent putative novel insect-specific viruses (ISVs) within families Chuviridae (3/33; partial genomes) and coding-complete sequences of Xinmoviridae (1/33), Rhabdoviridae (2/33) and Metaviridae (6/33); and five coding-complete sequences of already-known ISVs. Notably, two putative novel rhabdoviruses, Corixo rhabdovirus 1 and 2, were phylogenetically related to Coxipo dielmovirus, but separated from other Alpharhabdovirinae genera, sharing Anopheles spp. as host. Regarding multipartite families, sixteen segments of different putative novel viruses were identified (13 coding-complete segments) within Durnavirales (4/33), Elliovirales (1/33), Hareavirales (3/33) and Reovirales (8/33) orders. Overall, this study describes twenty-eight (28/33) putative novel ISVs and five (5/33) already described viruses using metagenomics approach.

Determination of Species Identity and Genetic Diversity of Aedes aegypti and Other Medically Important Mosquitoes of India Using DNA Barcoding.

Aedes aegypti-borne viruses (i.e., dengue, chikungunya, and Zika) have become endemic to India, posing a severe threat to public health. Vector control remains the mainstay of disease management due to nonavailability of licensed vaccines/therapeutics. Conventional morpho-taxonomical methods cannot differentiate between closely related sibling species or species complexes, and hence we evaluated two molecular markers, mitochondrial cytochrome c oxidase subunit 1 (Cox1) and nuclear DNA internal transcribed spacer 2 (-2) gene sequences, to characterize seven populations of Ae. aegypti and four medically important mosquito species (Aedes albopictus, Anopheles stephensi, Culex tritaeniorhyncus, and Culex murrelli). DNA extracted from the 11 mosquito populations (two mosquitoes per population) was polymerase chain reaction amplified, sequenced, and analyzed. Molecular characterization was found to be congruent with morphological identification, suggesting no variants or cryptic species exist in Ae. aegypti and the other mosquitoes studied. Phylogenetic analysis with sequences obtained with Cox1 gene of Ae. aegypti and other Aedes and non-Aedes mosquito species showed clustering of sequences from different species representing different clades, distinctly separating one taxon from the other, whereas ITS-2 sequences of Aedes aegypti from across the world clustered tightly. Nucleotide divergence values revealed a low percentage of intraspecies variation and a higher percentage of interspecies variation. The present study authenticates the applicability of Cox1 and ITS-2 in the precise identification of Ae. aegypti mosquitoes against cryptic or sibling species. Cox1 appeared to be a more reliable marker because it showed distinct clustering of mosquito species, and some sequence variations to represent genetic diversity.

Detection of Wuchereria bancrofti infection in mosquitoes in areas co-endemic with Brugia malayi in Balasore district, Odisha, India.

Lymphatic filariasis (LF) is a crippling and disfiguring parasitic condition. India accounts for 55% of the world's LF burden. The filarial parasite Wuchereria bancrofti is known to cause 99.4% of the cases while, Brugia malayi accounts for 0.6% of the issue occurring mainly in some pockets of Odisha and Kerala states. The Balasore (Baleswar) district of Odisha has been a known focus of B. malayi transmission. We employed molecular xenomonitoring to detect filarial parasite DNA in vectors. In six selected villages, Gravid traps were used to collect Culex mosquitoes and hand catch method using aspirators was followed for collection of mansonioides. A total of 2903 mosquitoes comprising of Cx. quinquefasciatus (n = 2611; 89.94%), Cx. tritaeniorhynchus (n = 100; 3.44%), Mansonia annuliferea (n = 139; 4.78%) and Mansonia uniformis (n = 53; 1.82%) were collected from six endemic villages. The species wise mosquitoes were made into 118 pools, each with a maximum of 25 mosquitoes, dried and transported to the laboratory at VCRC, Puducherry. The mosquito pools were subjected to parasite DNA extraction, followed by Real-time PCR using LDR and HhaI probes to detect W. bancrofti and B. malayi infections, respectively. Seven pools (6.66%) of Cx. quinquefasciatus, showed infection with only W. bancrofti while none of the pools of other mosquito species showed infection with either W. bancrofti or B. malayi. Although the study area is endemic to B. malayi, none of the vectors of B. malayi was found with parasite infection. This study highlights the ongoing transmission of bancroftian filariasis in the study villages of Balasore district of Odisha and its implications for evaluating LF elimination programme.

Molecular identification and GC-MS analysis of a newly isolated novel bacterium (Lysinibacillus sp. VCRC B655) for mosquito control.

BACKGROUND: Mosquitoes are widespread globally and have contributed to transmitting pathogens to humans and the burden of vector-borne diseases. They are effectively controlled at their larval stages by biocontrol agents. Unravelling natural sources for microbial agents can lead us to novel potential candidates for managing mosquito-borne diseases. In the present study, an attempt was made to isolate a novel bacterium from the field-collected agricultural soil for larvicidal activity and promising bacterial metabolites for human healthcare. METHODS AND RESULTS: Field-collected soil samples from the Union territory of Puducherry, India, have been used as the source of bacteria. Isolate VCRC B655 belonging to the genus Lysinibacillus was identified by 16S rRNA gene sequencing and exhibited promising larvicidal activity against different mosquito species, including Culex (Cx.) quinquefasciatus, Anopheles (An.) stephensi, and Aedes (Ae.) aegypti. The lethal concentration (LC) of Lysinibacillus sp. VCRCB655 was observed to be high for Cx. quiquefasciatus: LC50 at 0.047 mg/l, LC90 at 0.086 mg/l, followed by An. stephensi and Ae. aegypti (LC50: 0.6952 mg/l and 0.795 mg/l) respectively. Additionally, metabolic profiling of the culture supernatant was carried out through Gas chromatography and Mass spectrophotometry (GC/MS) and identified 15 major secondary metabolites of different metabolic classes. Diketopiperazine (DKPs), notably pyro lo [1, 2-a] pyrazine1, 4-dione, are the abundant compounds reported for antioxidant activity, and an insecticide compound benzeneacetic acid was also identified. CONCLUSIONS: A new bacterial isolate, Lysinibacillus sp. VCRC B655 has been identified with significant larvicidal activity against mosquito larvae with no observed in non-target organisms. GC-MS analysis revealed diverse bioactive compounds with substantial biological applications. In conclusion, Lysinibacillus sp. VCRC B655 showed promise as an alternative biocontrol agent for mosquito vector control, with additional biological applications further enhancing its significance.

Is Culex modestus a New Usutu virus vector?

Usutu virus is an emerging pathogen transmitted by mosquitoes. Culex modestus mosquitoes are widespread in Europe, but their role in disease transmission is poorly understood. Recent data from a single infectious mosquito suggested that Culex modestus could be an unrecognized vector for Usutu virus. In this study, our aim was to corroborate this finding using a larger sample size. We collected immature Culex modestus from a reedbed pond in Flemish Brabant, Belgium, and reared them in the laboratory until the third generation. Adult females were then experimentally infected with Usutu virus in a blood meal and incubated at 25 °C for 14 days. The presence of Usutu virus in the saliva, head and body of each female was determined by plaque assay and quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). The transmission efficiency was 54% (n = 15/28), confirming that Belgian Culex modestus can experimentally transmit Usutu virus.

Overwintering West Nile virus in active Culex pipiens mosquito populations in Greece.

The flavivirus West Nile Virus (WNV), which is transmitted by mosquitoes, poses a significant threat to both humans and animals, and its outbreaks often challenge public health in Europe and other continents. In recent years, there is an increasing trend of WNV incidence rates across several European countries. However, whether there is a year-round circulation or seasonal introduction has yet to be elucidated. Real-time polymerase chain reaction (PCR) identified WNV-positive Culex pipiens mosquitos in 6 out of 146 pools examined in winter 2022 that correspond to three out of the 24 study areas, located in two coastal regions units in Attica, Greece. Spatial dispersion of the six positive pools in the same region suggests a clustered circulation of WNV during the winter of 2022. This is the first study that documents the identification of WNV in Cx. pipiens populations, captured in adult traps during winter period. Our findings underscore the need to extend entomological surveillance programs to include the winter period, specifically in temperate climates and historically affected areas by WNV.

Description of New Morphological Variation of Culex (Culex) coronator Dyar and Knab, 1906 and First Report of Culex (Carrollia) bonnei Dyar, 1921 Found in the Central Region of Peru.

Mosquitoes (Diptera: Culicidae) pose a significant threat to public health worldwide, especially in tropical and subtropical regions, where they act as primary vectors in transmission of infectious agents. In Peru, 182 culicid species have been identified and several species of the genus Culex are known to transmit arboviruses. However, knowledge of mosquito diversity and distribution remains limited, with many studies focusing on specific regions only. Here, we describe a new morphological variation of Cx. (Culex) coronator Dyar and Knab, 1906, and report the presence of Culex (Carrollia) bonnei Dyar, 1921 in the central region of Peru, Huanuco. Specimens were obtained through larvae collections and identified through morphologic characterization, including dissection of male genitalia, and molecular analyses. In total, 17 mosquitoes were analyzed, and the genitalia of the male specimens allowed the identification of Cx. coronator and Cx. bonnei. Partial sequences of the CoxI gene corresponding to these two species were obtained (N = 10). Phylogenetic analysis revealed that the sequences of Cx. coronator grouped in a monophyletic clade with sequences ascribed to other species corresponding to the subgenus Carrollia, while Cx. bonnei specimens formed a monophyletic clade with homologous sequences from GenBank. This study underscores the importance of continued efforts to study the diversity and distribution of mosquitoes in Peru, including their potential role as vectors of human pathogens, to underpin effective disease control and prevention strategies, highlighting the importance of a complemented morphological and molecular analysis.

Integrated metabolomic analysis and molecular docking: Unveiling the potential of Nephrolepis exaltata (L.) Schott phytocompounds for mosquito control via glutathione-S-transferase targeting.

Plants contain a wide range of potential phytochemicals that are target-specific, and less toxic to human health. The present study aims to investigate the metabolomic profile of Nephrolepis exaltata (L.) Schott and its potential for mosquito control by targeting Glutathione-S-Transferase, focusing on the larvicidal activity against Culex pipiens. Crude extracts (CEs) were prepared using ethanol, ethyl acetate and n-hexane. CEs have been used for assessment of mosquitocidal bioassay. The metabolomic analyses for CEs were characterized for each CE by gas chromatography-mass spectrometry (GC-MS). The most efficient CE with the highest larval mortality and the least LC50 was the hexane CE. Then, alkaline phosphatase (ALP) activity, and glutathione-S-transferase (GST) activity were assessed in larvae treated with the hexane CE. The results demonstrated a decline in protein content, induction of ALP activity, and reduction in GST activity. Finally, molecular docking and dynamic simulation techniques were employed to evaluate the interaction between the hexane phytochemicals and the GST protein. D-(+)-Glucuronic acid, 3TMS derivative and Sebacic acid, 2TMS derivative showed best binding affinities to GST protein pointing to their interference with the enzyme detoxification functions, potentially leading to reduced ability to metabolize insecticides.

Synthesis and larvicidal efficacy of pyrazolopyrimidine derivatives conjugated with selenium nanoparticles against Culex pipiens L. and Musca domestica L. larvae.

The synthesized pyrazolopyrimidine derivatives conjugated with selenium nanoparticles were prepared via a reaction of pyrazolone 1 with aryl-aldehyde and malononitrile or 3-oxo-3-phenylpropanenitrile in the presence ammonium acetate or pipridine using an ultrasonic bath as a modified method in the organic synthesis for such materials. The structure of the synthesized compounds was elucidated through various techniques. All the synthesized pyrazolopyrimidines were used in the synthesis of selenium nanoparticles (SeNPs). These nanoparticles were confirmed using UV-spectra, Dynamic Light scattering and (TEM) techniques. The larvicidal efficiency;of the synthesized;compounds; was investigated against some strains such as Culex pipiens;and Musca domestica larvae. Bioassay test showed pyrazolopyrimide derivatives to exhibit an acceptable larvicidal;bio-efficacy. The derivative (3) exhibited;the highest;efficiency for more than; lab strains of both species. Moreover, C. pipiens larvae were more sensitive towards the examined compounds than M. domestica. The field;strain displayed lower affinity for the 2 folds compounds. Some biochemical changes were tracked through analysis of insect main metabolites (protein, lipid and carbohydrate), in addition to measuring the changes in seven enzymes after treatment. Generally, there was a reduction in the protein, lipids and carbohydrates after treatment with all tested compounds. Moreover, a decrement was noticed for acetylcholine esterase and glutathione;S-transferase; enzymes. There was an increment in the acid;phosphatase; and alkaline phosphatase. In addition, there was elevation in Phenoloxidase level but it noticed the declination in both Cytochrome P450 and Ascorbate peroxidase activity after treatment both flies with derivatives of selenium-nanoparticles in both lab and field strain. Generally, the experiments carried out indicate that antioxidant and detoxification enzymes may play a significant role in mechanism of action of our novel nanocompounds. The cytotoxicity of the synthesized compounds and conjugated with SeNPs showed enhanced compatibility with human normal fibroblast cell line (BJ1) with no toxic effect.