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.

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.

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.

Results of Integrated Transmission Assessment Surveys for Lymphatic Filariasis and Malaria in Haiti, 2017-2022.

Haiti is endemic for lymphatic filariasis (LF) and malaria, two mosquito-transmitted parasitic diseases targeted for elimination. The World Health Organization recommends a transmission assessment survey (TAS-1) to determine if LF prevalence is significantly beneath putative transmission thresholds (<2% antigen prevalence in Haiti, where Culex is the primary vector for Wuchereria bancrofti) to stop mass drug administration (MDA). Repeated TASs (TAS-2 and TAS-3) are recommended at 2-3-year intervals during post-treatment surveillance. From 2017 to 2022, The Carter Center assisted the Haitian Ministry of Public Health and Population in conducting 15 TASs in 11 evaluation units (EUs) encompassing 54 of the country's 146 districts. Children 6-7 years old were assessed for circulating filarial antigen (CFA) by Filariasis Test Strip: n = 5,239 in TAS-1; n = 11,866 in TAS-2; and n = 1,842 in TAS-3, of whom eight (0.15%), 20 (0.17%), and eight (0.43%) tested positive, respectively. The number of positive results in children was less than the threshold in each EU. When available, participants (n = 16,663) were also tested for malaria by rapid diagnostic test, with 31 (0.19%) children testing positive for Plasmodium falciparum. Integrated TASs provided an efficient means to collect epidemiological data for LF and malaria in Haiti. Results indicated thresholds for stopping and maintaining the halt of MDA for LF have been achieved in all EUs, with the halt of MDA for 571,358 people in four districts and the first TAS-3 surveys conducted in Haiti. Investigations are needed to assess the potential of ongoing LF transmission, especially in areas where CFA-positive samples were detected in TAS-3.

Exposure to Zika and chikungunya viruses impacts aspects of the vectorial capacity of Aedes aegypti and Culex quinquefasciatus.

Zika (ZIKV) and chikungunya (CHIKV) are arboviruses that cause infections in humans and can cause clinical complications, representing a worldwide public health problem. Aedes aegypti is the primary vector of these pathogens and Culex quinquefasciatus may be a potential ZIKV vector. This study aimed to evaluate fecundity, fertility, survival, longevity, and blood feeding activity in Ae. aegypti after exposure to ZIKV and CHIKV and, in Cx. quinquefasciatus exposed to ZIKV. Three colonies were evaluated: AeCamp (Ae. aegypti-field), RecL (Ae. aegypti-laboratory) and CqSLab (Cx. quinquefasciatus-laboratory). Seven to 10 days-old females from these colonies were exposed to artificial blood feeding with CHIKV or ZIKV. CHIKV caused reduction in fecundity and fertility in AeCamp and reduction in survival and fertility in RecL. ZIKV impacted survival in RecL, fertility in AeCamp and, fecundity and fertility in CqSLab. Both viruses had no effect on blood feeding activity. These results show that CHIKV produces a higher biological cost in Ae. aegypti, compared to ZIKV, and ZIKV differently alters the biological performance in colonies of Ae. aegypti and Cx. quinquefasciatus. These results provide a better understanding over the processes of virus-vector interaction and can shed light on the complexity of arbovirus transmission.

Essential oil and fenchone extracted from Tetradenia riparia (Hochstetter.) Codd (Lamiaceae) induce oxidative stress in Culex quinquefasciatus larvae (Diptera: Culicidae) without causing lethal effects on non-target animals.

We investigated the larvicidal activity of the essential oil (EO) from Tetradenia riparia and its majority compound fenchone for controlling Culex quinquefasciatus larvae, focusing on reactive oxygen and nitrogen species (RONS), catalase (CAT), glutathione S-transferase (GST), acetylcholinesterase (AChE) activities, and total thiol content as oxidative stress indicators. Moreover, the lethal effect of EO and fenchone was evaluated against Anisops bouvieri, Diplonychus indicus, Danio rerio, and Paracheirodon axelrodi. The EO and fenchone (5 to 25 µg/mL) showed larvicidal activity (LC50 from 16.05 to 18.94 µg/mL), followed by an overproduction of RONS, and changes in the activity of CAT, GST, AChE, and total thiol content. The Kaplan-Meier followed by Log-rank (Mantel-Cox) analyses showed a 100% survival rate for A. bouvieri, D. indicus, D. rerio, and P. axelrodi when exposed to EO and fenchone (262.6 and 302.60 µg/mL), while α-cypermethrin (0.25 µg/mL) was extremely toxic to these non-target animals, causing 100% of death. These findings emphasize that the EO from T. riparia and fenchone serve as suitable larvicides for controlling C. quinquefasciatus larvae, without imposing lethal effects on the non-target animals investigated.

Reducing the Antigen Prevalence Target Threshold for Stopping and Restarting Mass Drug Administration for Lymphatic Filariasis Elimination: A Model-Based Cost-effectiveness Simulation in Tanzania, India and Haiti.

BACKGROUND: The Global Programme to Eliminate Lymphatic Filariasis (GPELF) aims to reduce and maintain infection levels through mass drug administration (MDA), but there is evidence of ongoing transmission after MDA in areas where Culex mosquitoes are the main transmission vector, suggesting that a more stringent criterion is required for MDA decision making in these settings. METHODS: We use a transmission model to investigate how a lower prevalence threshold (<1% antigenemia [Ag] prevalence compared with <2% Ag prevalence) for MDA decision making would affect the probability of local elimination, health outcomes, the number of MDA rounds, including restarts, and program costs associated with MDA and surveys across different scenarios. To determine the cost-effectiveness of switching to a lower threshold, we simulated 65% and 80% MDA coverage of the total population for different willingness to pay per disability-adjusted life-year averted for India ($446.07), Tanzania ($389.83), and Haiti ($219.84). RESULTS: Our results suggest that with a lower Ag threshold, there is a small proportion of simulations where extra rounds are required to reach the target, but this also reduces the need to restart MDA later in the program. For 80% coverage, the lower threshold is cost-effective across all baseline prevalences for India, Tanzania, and Haiti. For 65% MDA coverage, the lower threshold is not cost-effective due to additional MDA rounds, although it increases the probability of local elimination. Valuing the benefits of elimination to align with the GPELF goals, we find that a willingness to pay per capita government expenditure of approximately $1000-$4000 for 1% increase in the probability of local elimination would be required to make a lower threshold cost-effective. CONCLUSIONS: Lower Ag thresholds for stopping MDAs generally mean a higher probability of local elimination, reducing long-term costs and health impacts. However, they may also lead to an increased number of MDA rounds required to reach the lower threshold and, therefore, increased short-term costs. Collectively, our analyses highlight that lower target Ag thresholds have the potential to assist programs in achieving lymphatic filariasis goals.

New artificial hematophagy system with attractive polymeric biofilm for maintenance of Culex quinquefasciatus (Diptera: Culicidae) in the laboratory.

BACKGROUND: Maintaining mosquito colonies in the laboratory requires a blood supply so that females' oocytes can mature and oviposition can take place. In this study, a new artificial hematophagy system for colonization and maintenance of Culex quinquefasciatus in the laboratory was developed and tested. METHODS: We developed an attractive polymeric biofilm including 25% L-lactic acid for use as a membrane in an artificial hematophagy system and compared the feeding rate of females with Parafilm-M®. We also evaluated the oviposition rate, larval survival and adult emergence of females fed through the attractive biofilm. RESULTS: The average percentage of female Cx. quinquefasciatus fed through the attractive biofilm was 87%, while only 20% became engorged with Parafilm-M® (p < 0.0001). Feeding through the attractive biofilm developed in this study produced high levels of evaluated biological parameters; the percentage of egg laying by females that underwent artificial hematophagy through the biofilm was 90%, with an average of 158 eggs per raft. From these eggs, 97% of the larvae hatched, of which 95% reached the pupal stage. The adult emergence rate corresponded to 93% of pupae. CONCLUSIONS: Insects fed with attractant through the biofilm system had a higher engorgement rate compared to those fed through Parafilm-M®. Our study is preliminary and suggests that polymeric biofilm has great potential for artificially feeding mosquitoes in the laboratory. Based on this research, new studies will be carried out with biofilm and different systems.

Exploring the range of Culex mosquitoes in Western Argentinean Patagonia, unveiling the presence of Culex pipiens bioform pipiens in South America.

Culicids in Argentinean Patagonia are characterized by low species diversity and adaptation to extreme environmental conditions, yet few studies have been conducted in the region. To further assess the occurrence of Culicidae in Western Patagonia, and in particular the presence of Culex pipiens bioforms at the southernmost extent of their distribution, immature and adult specimens were collected aboveground across various land uses located in shrubland, steppe, and deciduous forest between 38.96 and 46.55°S. Mosquitoes were reported at 35 of the 105 inspected sites. Five species from the genus Culex were identified, all of which were present in the steppe and the forest, while only Cx. apicinus and members of the Cx. pipiens complex were collected in the shrubland. Within the latter, a total of 150 specimens were molecularly identified by PCR amplification of Ace-2 and CQ11 loci. The first-to-date occurrence of bioform pipiens in South America is reported, along with the first records of Cx. quinquefasciatus signatures in Patagonia. In addition, the distribution of Cx. acharistus and Cx. dolosus as south as Santa Cruz province is expanded, and the first record of Cx. eduardoi in Río Negro province is provided. Immature specimens of Cx. pipiens were conspicuous in human-made aquatic habitats (both containers and in the ground), while Cx. acharistus was more prominent in artificial containers and Cx. eduardoi was mainly in ground habitats, either natural or human-made. These findings provide valuable insights into the distribution and ecological roles of these mosquito species in a region of extreme environmental conditions.

Beyond Borders: Investigating the Mysteries of Cacipacoré, a Lesser-Studied Arbovirus in Brazil.

Cacipacoré virus (CPCV) was discovered in 1977 deep in the Amazon rainforest from the blood of a black-faced ant thrush (Formicarius analis). As a member of the family Flaviviridae and genus orthoflavivirus, CPCV's intricate ecological association with vectors and hosts raises profound questions. CPCV's transmission cycle may involve birds, rodents, equids, bovines, marsupials, non-human primates, and bats as potential vertebrate hosts, whereas Culex and Aedes spp. mosquitoes have been implicated as potential vectors of transmission. The virus' isolation across diverse biomes, including urban settings, suggests its adaptability, as well as presents challenges for its accurate diagnosis, and thus its impact on veterinary and human health. With no specific treatment or vaccine, its prevention hinges on traditional arbovirus control measures. Here, we provide an overview of its ecology, transmission cycles, epidemiology, pathogenesis, and prevention, aiming at improving our ability to better understand this neglected arbovirus.

Current and future potential distribution of Culex (Melanoconion) (Diptera: Culicidae) of public health interest in the Neotropics.

Anthropogenic activities are altering ecosystem stability and climate worldwide, which is disturbing and shifting arbovirus vector distributions. Although the overall geographic range of some epidemiologically important species is recognized, the spatiotemporal variation for other species in the context of climate change remains poorly understood. Here we predict the current potential distribution of 9 species of Culex (Melanoconion) based on an ecological niche modeling (ENM) approach and assess spatiotemporal variation in future climate change in the Neotropics. The most important environmental predictors were the mean temperature of the warmest season (27 °C), precipitation during the driest month (50 mm), and precipitation during the warmest season (>200 mm). The best current model for each species was transferred to the future general circulation model IPSL-CM6A-LR, using 2 shared socioeconomic pathway scenarios (ssp1-2.6, ssp5-8.5). Under both scenarios of climatic change, an expansion of suitable areas can be observed followed by a strong reduction for the medium-long future under the worst scenario. The multivariate environmental similarity surface analysis indicated future novel climates outside the current range. However, none of the species would occur in those areas. Even if many challenges remain in improving methods for forecasting species responses to global climate change and arbovirus transmission, ENM has strong potential to be applied to the geographic characterization of these systems. Our study can be used for the monitoring of Culex (Melanoconion) species populations and their associated arboviruses, contributing to develop region-specific public health surveillance programs.

New occurrences of mosquitoes (Diptera: Culicidae) in the Atlantic Forest biome of the Brazilian Northeast.

BACKGROUND: Information regarding the distribution of Culicidae species in the northeastern region of Brazil is scarce. METHODS: Immatures were collected from approximately four fragments of the Atlantic Forest. RESULTS: This study presents new occurrences of 18 Culicidae species in Pernambuco state: Anopheles kompi, Georgecraigius fluviatilis, Culex bidens, Culex chidesteri, Culex bastagarius, Culex imitator, Mansonia humeralis, Wyeomyia incaudata, Uranotaenia apicalis, Culex mollis, Culex usquatus, Culex dunni, Culex serratimarge, Culex ybarmis, Culex microphyllus, Sabethes purpureus, Wyeomyia pilicauda, and Wyeomyia airosai. The last nine species were also new records for the northeast region. CONCLUSIONS: With the inclusion of these newly recorded species, the total number of mosquitoes documented in Pernambuco state now rises to 94.

Unraveling biotypes of the northern house mosquito, Culex pipiens s.l. (Diptera: Culicidae): molecular differentiation and morphometric analysis.

Geometric morphometrics was used to determine whether geographic isolation could explain differences in wing size and shape between and within continental (27°S to 41°S) and insular (Rapa Nui) populations of Culex pipiens s.s. Linnaeus and their biotypes (f. pipiens and f. molestus). Molecular protocols based on polymorphisms in the second intron of nuclear locus ace-2 (acetylcholinesterase-2) were used to differentiate Cx. pipiens s.s. from Cx. quinquefasciatus Say, and an assay based on polymorphisms in the flanking region of a microsatellite locus (CQ11) was used to identify biotypes. Culex pipiens f. molestus and hybrids shared larval habitats in all continental sites, while Cx. pipiens f. pipiens was found in 5 of the 10 sites. Only biotype molestus was found in Rapa Nui (Easter Island) Pipiens and molestus biotypes occur sympatrically in aboveground locations, and only molestus was found in the underground site (ME). Biotype molestus was dominant in rural locations and preferably anthropophilic. These results agree with the ecological descriptions previously reported for the biotypes of Cx. pipiens s.s. Procrustes ANOVA only showed differences in centroid size between biotypes in females and males and did not show significant differences in wing shape. However, we found significant differences among the geographic areas in the centroid size and wing shape of both females and males. Particularly, the population of Rapa Nui Island had shorter wings than the continental populations. The results highlight the effects of geographic and environmental processes on morphotypes in vector mosquitoes.

Postintervention Immunological and Entomological Survey of Lymphatic Filariasis in the City of Olinda, Brazil, 2015-2016.

Lymphatic filariasis (LF) is a leading cause of disability due to infectious disease worldwide. The Recife Metropolitan Region (RMR) is the only remaining focus of LF in Brazil, where the parasite Wuchereria bancrofti is transmitted solely by the mosquito Culex quinquefasciatus. This study reports the results of transmission assessment surveys and molecular xenomonitoring in the city of Olinda, RMR, after nearly 15 years (2015-2016) of interventions for LF elimination. Participants were screened for W. bancrofti antigen via immunochromatographic card tests (ICT) in: 1) door-to-door surveys conducted for all children aged 5-7 years from 4 out of 17 intervention areas treated with at least five annual doses of mass drug administration (MDA), and 2) a two-stage cluster sampling survey of residents aged 5 years and older in non-MDA areas. Mosquitoes were collected via handheld aspirators in four MDA areas, differentiated by species, sex, and physiological status, pooled into groups of up to 10 blood-fed, semigravid, and gravid mosquitoes, and screened for W. bancrofti infection by real-time quantitative polymerase chain reaction (RT-qPCR). All 1,170 children from MDA areas and the entire population sample of 990 residents in non-MDA areas were ICT negative. In MDA areas, a total of 3,152 female Cx. quinquefasciatus mosquitoes in 277 households (range, 0-296 mosquitoes per house) were collected via aspiration. RT-qPCR of 233 pools of mosquitos were negative for W. bancrofti RNA; an independent reference laboratory confirmed these results. These results provide evidence that LF transmission has been halted in this setting.

Blood meal sources of mosquitoes (Diptera: Culicidae) in domestic and open green environments from two urbanisations of temperate Argentina.

Understanding the blood-feeding patterns of mosquitoes is essential for evaluating their potential as disease vectors, especially in urban areas where mosquitoes coexist with humans, domestic animals and wildlife. This study aimed to bridge a substantial gap in regional knowledge by identifying the blood meal sources of field-collected mosquitoes in domestic and open green environments from two urbanisations of temperate Argentina, the Área Metropolitana de Buenos Aires (AMBA) and Tandil, using molecular techniques. Female mosquitoes were collected from November 2019 to March 2020 and April-May 2021. A bipartite network analysis was performed for each environment and urbanisation. A total of 103 blood meals from Aedes (2 species) and Culex (7 species) were identified. Among these, five mammal and 18 bird species were recognised as hosts. Aedes mosquitoes exclusively fed on mammals, while Culex mosquitoes exhibited a broader host range including both birds and mammals. In AMBA, the open green environments were composed by more mosquito species than the domestic environments, while both presented similar numbers of vertebrate species. In contrast, in open green environments from Tandil only blood-fed Aedes albifasciatus were collected. For open green environments of AMBA and domestic environments of Tandil, results suggested some degree of host selection. For the three main vectors of diseases in the region, Aedes aegypti, Ae. albifasciatus and Culex pipiens molestus, we present the first molecular evidence of human blood meals in South America. Epidemiological significance of the present findings is discussed.

West Nile virus in Mexico: Why vectors matter for explaining the current absence of epidemics.

Since 2002, West Nile Virus (WNV) has been reported in 18 states in Mexico, either by PCR or serological testing. However, it is believed that the virus is present in more states. Only four states (out of 32) have reported confirmed human cases, and one state has serological evidence. In the country, WNV is present in mainly horses and birds, but its presence extends to crocodiles, felines, canines, swines, donkeys, caprines, antilopes, cattle, bats, and camelids. Positive mosquito species include Aedes and Culex spp. Different hypotheses have been proposed to explain the absence of WNV epidemics in Latin America. Since some regions of Mexico and the United States share ecological and climatic conditions, these hypotheses may not be sufficient to account for the absence of WNV outbreaks or epidemics. This paper discusses the proposed ideas and attempts to contextualize them for Mexico, particularly for the U.S.-Mexico border, where WNV infections have been reported in humans, horses, and mosquitoes. We propose that integration of urban ecology and entomology knowledge is needed to better understand the absence of WN cases in Mexico.

Mapeamento da infestação por Aedes aegypti e Culex spp. adultos em Campinas (SP), Brasil / Mapping of Aedes aegypti and Culex spp. adults in Campinas (SP), Brazil

Introdução: Algumas arboviroses transmitidas por vetores como Aedes aegypti e Culex spp. são consideradas de grande importância epidemiológica, entre estas, destacam-se a dengue, Zika, chikungunya, febre amarela e febre do Nilo ocidental. A transmissão dos arbovírus ocorre enquanto as fêmeas infectadas realizam a hematofagia e as atuais medidas que visam a redução dessas arboviroses na população se dão principalmente com foco na redução da população de mosquitos. Índices de vigilância entomológica fazem parte das rotinas de programas de controle. Estudos recentes têm questionado a eficácia da utilização de índices de formas imaturas do vetor para predição do risco de transmissão de arboviroses e associação com incidência de casos. Isso indica que realizar a vigilância com a forma adulta dos vetores pode ser uma alternativa de maior eficácia. Objetivos: Estimar, predizer e mapear a infestação por Ae. aegypti e o Culex spp. associadas a variáveis de uso e ocupação do solo no município de Campinas/SP no período de verão entre os anos de 2021 a 2023. Material e Métodos: Trata-se de um estudo transversal realizado por meio de coletas mensais de mosquitos adultos realizadas em 200 armadilhas BG MosquititoTM distribuídas aleatoriamente na área urbana de Campinas. Foram realizadas regressões múltiplas em um contexto bayesiano e geoestatístico utilizando a abordagem de aproximações de Laplace aninhadas e integradas e equações diferenciais parciais estocásticas. Foram consideradas como covariáveis o Índice Brasileiro de Privação (IBP) e informações sobre uso e ocupação do solo obtidas de imagens de satélite. Resultados: O melhor modelo de regressão para o número de Ae. aegypti fêmeas encontrou associação positiva com o IBP, uma medida do nível socioeconômico, e árvores. Quanto aos machos, o melhor modelo mostrou associação positiva com cimento e telha de zinco. O melhor modelo para o total de mosquitos Ae. aegypti mostrou associação positiva com o IBP, cimento e árvore e o mesmo ocorreu para Culex spp. Foram elaborados mapas com a predição da quantidade de mosquitos para cada modelo considerando a distribuição das covariáveis presentes na área de estudo. Conclusões: Com esse estudo, foi possível modelar as quantidades de fêmeas, machos e total de Ae. aegypti e total de Culex spp., com base nas informações obtidas com a partir da instalação das armadilhas de adultos, e predizer os níveis de infestação para todos os locais da área de estudo. Variáveis socioeconômicas e de uso e ocupação do solo mostraram-se associadas aos números de mosquitos coletados, com exceção do nível socioeconômico para os machos de Ae. aegypti. Os resultados mostram que a utilização dessas covariáveis nas modelagens foram úteis para melhorar as predições nos locais não amostrados. Nosso estudo mostrou ser possível identificar áreas de maior risco para infestação de forma independente dos limites administrativos da área de estudo, quer sejam bairros ou distritos. Além disso, mostrou ser viável o uso de armadilhas de adultos para realização de vigilância entomológica.

Introduction: Some arboviruses transmitted by vectors such Aedes aegypti and Culex spp. are considered of great epidemiological importance, among which dengue, Zika and chikungunya, yellow fever and West Nile fever stand out. The transmission of arboviruses occurs while infected females are carrying out hematophagy, and current measures aimed at reducing these arboviruses in the population are mainly focused on reducing the mosquito population. Entomological surveillance indices are part of the routines of control programs. Recent studies have questioned the effectiveness of using indices of immature forms of the vector to predict the risk of arbovirus transmission and association with the incidence of cases. This indicates that carrying out surveillance with the adult form of the vectors may be a more effective alternative. Objectives: Estimate, predict and map the infestation of Ae. aegypti and Culex spp. associated with land use and occupation variables in the city of Campinas (SP) in the summer period between 2021 to 2023. Material and Methods: This is a cross-sectional study carried out through monthly collections of adult mosquitoes in 200 BG MosquititoTM traps randomly distributed in the urban area of Campinas. Multiple regressions were performed in a Bayesian and geostatistical context using the approach of nested and integrated Laplace approximations and stochastic partial differential equations. The Brazilian Deprivation Index (IBP) and information on land use and occupation obtained from satellite images were considered as covariates. Results: The best regression model for the number of female Ae. aegypti found a positive association with the IBP, a measure of socioeconomic status, and trees. As for males, the best model considered showed a positive association with cement and zinc tiles. The best model for the total number of Ae. aegypti showed a positive association with IBP, cement and trees, as the same occurred for Culex spp. Conclusions: With this study, it was possible to model the numbers of females, males and total Ae. aegypti and total Culex spp., based on the information obtained from the installation of adult traps, and to predict the infestation levels for all locations in the study area. Socioeconomic and land use and occupation variables were associated with the numbers of mosquitoes collected, with the exception of the socioeconomic level for males of Ae. aegypti. The results show that the use of these covariates in the models was useful to improve predictions in the non-sampled locations. Our study showed that it is possible to identify areas of greater risk for infestation independently of the administrative boundaries of the study area, whether they are neighborhoods, districts. Furthermore, it was shown to be feasible to use adult traps to carry out entomological surveillance.

Species diversity pattern of mosquitoes (Diptera: Culicidae) breeding in different permanent, temporary and natural container habitats of Peshawar, KP Pakistan / Padrão de diversidade de espécies de mosquitos (Dípteros: Culicidae) reproduzidos em diferentes habitats permanentes, naturais temporárias e contentores de Peshawar, KP Paquistão

To determine the species composition, relative abundance and seasonal variation of different mosquitoes Genera (Aedes, Anopheles, Armigeres, Culex, and Culiseta) in different habitats the present research work was carried out in Entomology Research Laboratory of The University of Peshawar. Sampling performed from variety of permanent and temporary breeding habitats was carried out on monthly basis from targeted breeding sites for two consecutive years through dipping method. Species diversity in the survey sites was noted. Collection from these seventeen various types of potential larval habitats, yielded a total of 42,430 immature constituting 41,556 larvae and 874 pupae. Among these only 19,651 adult mosquitoes emerged comprising 11,512 female and 8,139 male mosquitoes. 78% (n= 15333) of mosquito larvae were from permanent and 22% (n=4318) were from temporary breeding sites. This study showed that Peshawar valley harbours 15 species from the genera Aedes, Anopheles, Armigeres, Culex and Culiseta. When the density of each species was examined, Culex quinquifasciatus was found to be dominant (79%) and constant in distribution. Among the temporary habitats Aedes albopictus was found as the most prevalent species particularly from tree holes and water cisterns. The highest intensity of mosquitoes was in June (2243 emerged adults) and November (2667 emerged adults) while the lowest was in January (203 emerged adults). A perfect positive correlation (r = +0.8) was found between temperature and population of mosquitoes (df 10 and α 0.05). The species diversity index for mosquitoes remained between 0.12 and 1.76. The Margalef's richness components was noticeably low for bamboo traps (0.2) and fairly high for rice fields, Percolating water and Animal tracks (1.3) which shows the abundance of mosquito species in these habitats. Similarly Pielou's Evenness was highest for bamboo traps (E=1) showing species uniform distribution. Animal tracks were presumed not only the diverse habitat rather also possessed high value for species richness and species evenness. Temperature, rainfall, humidity and other related attributes responsible for species variation and abundance need to be analysed further to pave way for controlling vector species in their oviposition targeted sites.

Para determinar a composição de espécies, abundância relativa e variação sazonal de diferentes gêneros de mosquitos (Aedes, Anopheles, Armigeres, Culex e Culiseta) em diferentes habitats, o presente trabalho foi realizado no Laboratório de Pesquisa em Entomologia da Universidade de Peshawar. A amostragem coletada a partir de uma variedade de habitats de reprodução permanentes e temporários foi realizada mensalmente a partir de locais de reprodução alvo por 2 anos consecutivos através do método de imersão. A diversidade de espécies nos locais de pesquisa foi anotada. A coleta desses 17 tipos diferentes de habitats larvais potenciais rendeu um total de 42.430 imaturos, constituindo 41.556 larvas e 874 pupas. Destes, emergiram apenas 19.651 mosquitos adultos, sendo 11.512 fêmeas e 8.139 machos. 78% (n = 15333) das larvas do mosquito eram de criadouros permanentes e 22% (n = 4318) de criadouros temporários. Este estudo mostrou que o vale de Peshawar abriga 15 espécies dos gêneros Aedes, Anopheles, Armigeres, Culex e Culiseta. Quando a densidade de cada espécie foi examinada, Culex quinquifasciatus foi considerado dominante (79%) e constante na distribuição. Entre os habitats temporários, o Aedes albopictus foi encontrado como a espécie mais prevalente, principalmente em ocos de árvores e cisternas de água. A maior intensidade de mosquitos foi em junho (2.243 adultos emergidos) e novembro (2.667 adultos emergidos), enquanto a menor foi em janeiro (203 adultos emergidos). Uma correlação positiva perfeita (r = +0,8) foi encontrada entre temperatura e população de mosquitos (DF 10 e α 0,05). O índice de diversidade de espécies de mosquitos permaneceu entre 0,12 e 1,76. Os componentes de riqueza de Margalef foram visivelmente baixos para armadilhas de bambu (0,2) e razoavelmente altos para campos de arroz, água percolada e rastros de animais (1,3), o que mostra a abundância de espécies de mosquitos nesses habitats. Da mesma forma, a uniformidade de Pielou foi maior para armadilhas de bambu (E = 1), mostrando distribuição uniforme das espécies. As pegadas de animais foram presumidas não apenas como habitat diverso, mas também possuíam alto valor para riqueza e uniformidade de espécies. Temperatura, chuva, umidade e outros atributos relacionados responsáveis pela variação e abundância das espécies precisam ser analisados mais a fundo para abrir caminho para o controle de espécies de vetores em seus locais de oviposição alvo.

Pathology of an iridescent virus in immature Culex pipiens L. (Diptera, Culicidae).

Iridovirus in Culex pipiens was reported for the first time in 2012. Later studies of horizontal transmission were performed, in which an interaction with the parasite Strelkovimermis spiculatus acting as viral vector was recognized. In the present study, we observed aspects of the pathology produced by an invertebrate iridescent virus in laboratory infected immature Cx. pipiens as well as in infected immature Cx. pipiens in the field. In the laboratory infected larvae, the infection and mortality were asynchronous. Signs of infection in larvae exposed to the virus were observed between the second and the fourth days post-exposure in 99% of the cases, while the highest daily record of visible infected larvae (52%) was observed on the third day post exposure. Moreover, 79% of confirmed virus infected larvae died in the first 10 days after exposure. The Median Lethal Time was eight days. Several tissues were found to be infected and the common sites of replication were the fat body, epidermis and epithelial derivatives, such as the imaginal discs and the tracheal epithelium. Moreover, infection in the salivary glands, gastric ceca and posterior gut have not been previously documented on other mosquito iridescent viruses.

Characterizing viral species in mosquitoes (Culicidae) in the Colombian Orinoco: insights from a preliminary metagenomic study.

Mosquitoes (Diptera: Culicidae) are primary vectors of arthropod-borne viruses (arboviruses) that pose significant public health threats. Recent advances in sequencing technology emphasize the importance of understanding the arboviruses and insect-specific viruses (ISVs) hosted by mosquitoes, collectively called the "virome". Colombia, a tropical country with favorable conditions for the development and adaptation of multiple species of Culicidae, offers a favorable scenario for the transmission of epidemiologically important arboviruses. However, entomovirological surveillance studies are scarce in rural areas of the country, where humans, mosquitoes, and animals (both domestic and wild) coexist, leading to a higher risk of transmission of zoonotic diseases to humans. Thus, our study aimed to perform a preliminary metagenomic analysis of the mosquitoes of special relevance to public health belonging to the genera Ochlerotatus, Culex, Limatus, Mansonia, Psorophora, and Sabethes, within a rural savanna ecosystem in the Colombian Orinoco. We employed third-generation sequencing technology (Oxford Nanopore Technologies; ONT) to describe the virome of mosquitoes samples. Our results revealed that the virome was primarily shaped by insect-specific viruses (ISVs), with the Iflaviridae family being the most prevalent across all mosquito samples. Furthermore, we identified a group of ISVs that were common in all mosquito species tested, displaying the highest relative abundance concerning other groups of viruses. Notably, Hanko iflavirus-1 was especially prevalent in Culex eknomios (88.4%) and Ochlerotatus serratus (88.0%). Additionally, other ISVs, such as Guadalupe mosquito virus (GMV), Hubei mosquito virus1 (HMV1), Uxmal virus, Tanay virus, Cordoba virus, and Castlerea virus (all belonging to the Negevirus genus), were found as common viral species among the mosquitoes, although in lower proportions. These initial findings contribute to our understanding of ISVs within mosquito vectors of the Culicidae family in the Eastern Plains of Colombia. We recommend that future research explore deeper into ISV species shared among diverse vector species, and their potential interactions with arboviruses. In addition, we also showed the need for a thorough exploration of the influence of local rural habitat conditions on the shape of the virome in mosquito vectors.