In Vitro Assessment of Metarhizium Anisopliae Pathogenicity Against Aedes Aegypti Life Stages.

Aedes aegypti transmits the arboviruses that cause dengue, zika, and chikungunya. Entomopathogenic fungi are beneficial microorganisms that can be incorporated into current strategies against mosquitoes of public health concern. This study molecularly identified the Metarhizium anisopliae CG 153 isolate and evaluated its virulence against larvae, pupae, and adults (both males and females) of Ae. aegypti. Different concentrations of conidia were used (1 × 104-8 conidia mL-1). Larval and pupal survival was monitored daily for seven and three days, respectively, while adults were monitored for 15 days. The efficacy of M. anisopliae sensu stricto was concentration-dependent, with higher concentrations achieving better results, demonstrating greater virulence against larval and adult stages of Ae. aegypti. The fungus reduced the larval survival by 95,5% (1 × 108 con.mL-1), 94,4% (1 × 107 con.mL-1), 78,9% (1 × 106 con.mL-1), 62,2% (1 × 105 con.mL-1), and 41,1% (1 × 104 con.mL-1) after seven days. Adults also showed susceptibility to the fungus, with no observed difference in susceptibility between males and females. Over 15 days of monitoring, adult survival rates ranged from approximately 6.7% to 72%. Pupae exhibited lower susceptibility to the fungus across different concentrations, with survival rates ranging from approximately 87.8% to 100%. This study highlights the high effectiveness of M. anisopliae CG 153 against both Ae. aegypti larvae and adults (male and female) under controlled conditions, suggesting its promising potential for further evaluation and application in field conditions.

Robust mosquito species identification from diverse body and wing images using deep learning.

Mosquito-borne diseases are a major global health threat. Traditional morphological or molecular methods for identifying mosquito species often require specialized expertise or expensive laboratory equipment. The use of convolutional neural networks (CNNs) to identify mosquito species based on images may offer a promising alternative, but their practical implementation often remains limited. This study explores the applicability of CNNs in classifying mosquito species. It compares the efficacy of body and wing depictions across three image collection methods: a smartphone, macro-lens attached to a smartphone and a professional stereomicroscope. The study included 796 specimens of four morphologically similar Aedes species, Aedes aegypti, Ae. albopictus, Ae. koreicus and Ae. japonicus japonicus. The findings of this study indicate that CNN models demonstrate superior performance in wing-based classification 87.6% (95% CI: 84.2-91.0) compared to body-based classification 78.9% (95% CI: 77.7-80.0). Nevertheless, there are notable limitations of CNNs as they perform reliably across multiple devices only when trained specifically on those devices, resulting in an average decline of mean accuracy by 14%, even with extensive image augmentation. Additionally, we also estimate the required training data volume for effective classification, noting a reduced requirement for wing-based classification compared to body-based methods. Our study underscores the viability of both body and wing classification methods for mosquito species identification while emphasizing the need to address practical constraints in developing accessible classification systems.

Learning outcomes for participants in citizen science mosquito surveillance.

Although citizen science initiatives have been increasing globally, there is still a gap in understanding how they can result in sustainable benefits for citizen scientists. This article addresses dual goals of (i) collecting relevant data on potential vector mosquitoes and (ii) delivering learning outcomes among participants in a citizen science mosquito surveillance program. Mozzie Monitors uses an e-entomology approach to collect and identify mosquitoes of medical importance. This study used quantitative, qualitative, and mixed method approaches, comprised of before and after longitudinal surveys, in-depth interviews and descriptive assessment of mosquito attributes to assess participants' educational gains and data collection scalability. Results showed that mosquito abundance and diversity differed in each study location, with Aedes notoscriptus (Skuse) being the most common mosquito reported in all areas. Citizen scientists were predominantly women over 50 and highly educated. The before-and-after analysis showed that participants learned how to identify the most common mosquito species after participating in the program. They also improved their technical skills in mosquito photography, increasing the rates of identifiable photos. Finally, participating in this citizen science program resulted in behavior changes, with participants starting to look for mosquito eggs and larvae in their backyards to manage mosquito populations. The mixed methods used in this research showed increased participants' confidence, self-efficacy, and engagement throughout the trial. Overall, this study demonstrated the potential of Mozzie Monitors to contribute to the dual goals of mosquito data contribution and citizen scientists' educational outcomes for improved public health.

Senescence of humoral antimicrobial immunity occurs in infected mosquitoes when the temperature is higher.

Mosquitoes cannot use metabolism to regulate their body temperature, and therefore, climate warming is altering their physiology. Mosquitoes also experience a physiological decline with aging, a phenomenon called senescence. Because both high temperature and aging are detrimental to mosquitoes, we hypothesized that high temperatures accelerate senescence. Here, we investigated how temperature and aging, independently and interactively, shape the antimicrobial immune response of the mosquito, Anopheles gambiae. Using a zone-of-inhibition assay that measures the antimicrobial activity of hemolymph, we found that antimicrobial activity increases following infection. Moreover, in infected mosquitoes, antimicrobial activity weakens as the temperature rises to 32C, and antimicrobial activity increases from 1 to 5 days of age and stabilizes with further aging. Importantly, in E. coli-infected mosquitoes, higher temperature causes an aging-dependent decline in antimicrobial activity. Altogether, this study demonstrates that higher temperature can accelerate immune senescence in infected mosquitoes, thereby interactively shaping their ability to fight an infection.

Public health contributions of entomological surveillance of West Nile virus (WNV) and other mosquito-borne arboviruses in a context of climate change.

Background: Climate change is likely to increase the risk of human transmission of arboviruses endemic to Canada, including West Nile virus (WNV), Eastern equine encephalitis virus (EEEV) and California serogroup virus (CSV), calling for enhanced surveillance, including entomological surveillance targeting mosquito vectors. A scoping review was carried out to document the public health contributions of entomological surveillance of arboviruses of importance in Canada. Methods: The Ovid® and EBSCO platforms and the grey literature were searched to identify documents published between 2009 and 2023, in English or French, dealing with entomological surveillance of arboviruses of interest, conducted annually for human health purposes under the aegis of a government authority, with specified public health objectives and actions. Results: The 42 selected publications mainly reported two public health objectives of adult mosquito surveillance: early warning of viral circulation and assessment of the level of risk of human transmission. Recommended actions included clinical preparedness, risk communication, promotion of personal protection measures and vector control. The main objectives of immature mosquito surveillance were to identify sites with high larval densities, in order to reduce/eliminate them and target the application of larvicides. Conclusion: In a context of climate change favouring the spread of arboviruses, this study highlights the potential public health contributions of regular entomological surveillance of endemic arboviruses of importance in Canada. It helps support concrete actions to protect the health of the population from the risks of arboviral transmission.

Factors influencing community engagement approaches used in Aedes aegypti management in Cairns, Australia.

ISSUE ADDRESSED: An important part of preventing and managing Aedes-borne mosquito disease outbreak risk is engaging the community. Research shows that high-income countries tend to use top-down measures for Aedes mosquito management, favouring educational approaches to engage the community over participatory approaches that actively involve and empower the community in addressing disease risk. Little is known about the reasons behind the use of these approaches and how they could be strengthened. This research explores the community engagement approaches used in Aedes mosquito management in Cairns, Queensland, Australia and the factors influencing the choice of these approaches. METHODS: A case study design was used, drawing on two qualitative methods-key informant, semi-structured interviews (n = 25), and a document review (n = 20). Thematic analysis was used to identify, analyse and attribute meaning from the data. RESULTS: Various approaches were used to engage the community, including direct interaction through door-to-door inspections, broad outreach via mass media campaigns, and community participation in a novel mosquito replacement strategy. Factors influencing the choice of these approaches included government legislative responsibilities, research-related ethical obligations, work norms within local government and public health units, the perceived importance of gaining community trust, constraints on workforce capacity, time and funding. CONCLUSIONS: There were multiple factors influencing the community engagement approaches used in this study. Resource constraints, institutional norms and prevailing attitudes and beliefs were identified as hindering the use of more empowering approaches to engaging the community. These barriers should be considered and addressed in the planning of Aedes mosquito management to better support community engagement in this setting. SO WHAT?: Community engagement is an important aspect of managing the Aedes mosquito disease threat. With the global increase in Aedes mosquito-borne disease risk, these findings can help other at-risk settings understand potential organisational impediments to engaging the community. This is particularly important when advocating for the inclusion of bottom-up approaches in policy, and to ensure sufficient resources are allocated to strengthen community engagement in Aedes mosquito management.

Diversity of biting midges, mosquitoes and sand flies at four dog shelters in rural and peri-urban areas of Central Morocco.

Blood-feeding arthropods are involved in the transmission of several pathogens that have a major impact on public health. Entomological investigations highlighted the composition, abundance, and diversity of flying hematophagous arthropods at four dog shelters located in central Morocco during an eight-month study, with the aim of discussing their vectorial roles and assessing the risk of these shelters as foci for zoonotic diseases. Monitoring of the arthropod fauna for 64 catch nights resulted in the collection of 2,321 biting midges (Ceratopogonidae), 570 mosquitoes (Culicidae), and 475 sand flies (Psychodidae). Fourteen Culicoides species were recorded and dominant species were Culicoides imicola (55.96%), C. paolae (16.07%), C. circumscriptus (10.29%), and C. newsteadi (5.77%). Three mosquito species were collected, including Culex pipiens s.l. (96.84%), Culiseta longiareolata (2.80%), and Cx. perexiguus (0.36%). Ten sand fly species were collected, including seven Phlebotomus species (62.70%) and three Sergentomyia species (37.30%); Sergentomyia minuta was the most dominant species (34.31%), followed by Phlebotomus sergenti (32.42%), typical Ph. perniciosus (8.63%), Ph. alexandri (6.94%), and Ph. riouxi (6.52%). The coexistence of several vectors in these study areas indicates the potential circulation of a wide range of pathogens, including zoonotic ones, thus requiring the implementation of surveillance and control programs to prevent the emergence and spread of disease outbreaks.

Title: Diversité des culicoïdes, moustiques et phlébotomes collectés au niveau de quatre chenils du Maroc central. Abstract: Les arthropodes hématophages sont impliqués dans la transmission de plusieurs agents pathogènes ayant un impact majeur sur la santé publique. Des investigations entomologiques ont mis en évidence la composition, l'abondance et la diversité des arthropodes hématophages volants dans quatre chenils situés au centre du Maroc au cours d'une étude de huit mois, dans le but de discuter de leurs rôles vectoriels et d'évaluer le risque de ces chenils comme foyers de maladies zoonotiques. Le suivi de la faune des arthropodes au cours de 64 nuits de capture a permis la collecte de 2 321 culicoïdes (Ceratopogonidae), 570 moustiques (Culicidae) et 475 phlébotomes (Psychodidae). Quatorze espèces de Culicoides ont été recensées et les espèces dominantes étaient Culicoides imicola (55,96 %), C. paolae (16,07 %), C. circumscriptus (10,29 %) et C. newsteadi (5,77 %). Trois espèces de moustiques ont été collectées, dont Culex pipiens s.l. (96,84 %), Culiseta longiareolata (2,80 %) et Cx. perexiguus (0,36 %). Dix espèces de phlébotomes ont été collectées, dont sept espèces de Phlebotomus (62,70 %) et trois espèces de Sergentomyia (37,30 %); Sergentomyia minuta était l'espèce dominante (34,31 %), suivie de Phlebotomus sergenti (32,42 %), Ph. perniciosus typique (8,63 %), Ph. alexandri (6,94 %) et Ph. riouxi (6,52 %). La coexistence de plusieurs vecteurs dans ces zones d'étude indique la circulation potentielle d'un large éventail d'agents pathogènes, y compris zoonotiques, ce qui nécessite la mise en œuvre de programmes de surveillance et de contrôle pour prévenir l'émergence et la propagation d'épidémies.

The First Isolation of Insect-Specific Alphavirus (Agua Salud alphavirus) in Culex (Melanoconion) Mosquitoes in the Brazilian Amazon.

Advances in diagnostic techniques coupled with ongoing environmental changes have resulted in intensified surveillance and monitoring of arbovirus circulation in the Amazon. This increased effort has resulted in increased detection of insect-specific viruses among hematophagous arthropods collected in the field. This study aimed to document the first isolation of Agua Salud alphavirus in mosquitoes collected within the Brazilian Amazon. Arthropods belonging to the family Culicidae were collected within a forest fragment located in the Environmental Protection Area of the metropolitan region of Belem. Subsequently, these specimens were meticulously identified to the species level. Afterward, the collected batches were macerated, and the resulting supernatant was then inoculated into C6/36 and Vero cell cultures to facilitate viral isolation. The presence of arboviruses within the inoculated cell cultures was determined through indirect immunofluorescence analysis. Furthermore, positive supernatant samples underwent nucleotide sequencing to precisely identify the viral strains present. Notably, a batch containing Culex (Melanoconion) mosquitoes was identified to be positive for the genus Alphavirus via indirect immunofluorescence. This study is the first report on insect-specific alphavirus isolation in Brazil and the first-ever description of Agua Salud alphavirus isolation within Amazon Forest remnants.

Immunomodulation in dengue: towards deciphering dengue severity markers.

BACKGROUND: Dengue is a vector-borne debilitating disease that is manifested as mild dengue fever, dengue with warning signs, and severe dengue. Dengue infection provokes a collective immune response; in particular, the innate immune response plays a key role in primary infection and adaptive immunity during secondary infection. In this review, we comprehensively walk through the various markers of immune response against dengue pathogenesis and outcome. MAIN BODY: Innate immune response against dengue involves a collective response through the expression of proinflammatory cytokines, such as tumor necrosis factors (TNFs), interferons (IFNs), and interleukins (ILs), in addition to anti-inflammatory cytokines and toll-like receptors (TLRs) in modulating viral pathogenesis. Monocytes, dendritic cells (DCs), and mast cells are the primary innate immune cells initially infected by DENV. Such immune cells modulate the expression of various markers, which can influence disease severity by aiding virus entry and proinflammatory responses. Adaptive immune response is mainly aided by B and T lymphocytes, which stimulate the formation of germinal centers for plasmablast development and antibody production. Such antibodies are serotype-dependent and can aid in virus entry during secondary infection, mediated through a different serotype, such as in antibody-dependent enhancement (ADE), leading to DENV severity. The entire immunological repertoire is exhibited differently depending on the immune status of the individual. SHORT CONCLUSION: Dengue fever through severe dengue proceeds along with the modulated expression of several immune markers. In particular, TLR2, TNF-α, IFN-I, IL-6, IL-8, IL-17 and IL-10, in addition to intermediate monocytes (CD14+CD16+) and Th17 (CD4+IL-17+) cells are highly expressed during severe dengue. Such markers could assist greatly in severity assessment, prompt diagnosis, and treatment.

MALDI-TOF MS Profiling and Its Contribution to Mosquito-Borne Diseases: A Systematic Review.

Mosquito-borne diseases are responsible for hundreds of thousands of deaths per year. The identification and control of the vectors that transmit pathogens to humans are crucial for disease prevention and management. Currently, morphological classification and molecular analyses via DNA barcoding are the standard methods used for vector identification. However, these approaches have several limitations. In the last decade, matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) profiling has emerged as an innovative technology in biological sciences and is now considered as a relevant tool for the identification of pathogens and arthropods. Beyond species identification, this tool is also valuable for determining various life traits of arthropod vectors. The purpose of the present systematic review was to highlight the contribution of MALDI-TOF MS to the surveillance and control of mosquito-borne diseases. Published articles from January 2003 to August 2024 were retrieved, focusing on different aspects of mosquito life traits that could be determinants in disease transmission and vector management. The screening of the scientific literature resulted in the selection of 54 published articles that assessed MALDI-TOF MS profiling to study various mosquito biological factors, such species identification, life expectancy, gender, trophic preferences, microbiota, and insecticide resistance. Although a large majority of the selected articles focused on species identification, the present review shows that MALDI-TOF MS profiling is promising for rapidly identifying various mosquito life traits, with high-throughput capacity, reliability, and low cost. The strengths and weaknesses of this proteomic tool for vector control and surveillance are discussed.

Mark-Release-Recapture Trial with Aedes albopictus (Diptera, Culicidae) Irradiated Males: Population Parameters and Climatic Factors.

Aedes albopictus is considered one of the major invasive species in the world and can transmit viruses such as dengue, Zika, or chikungunya. The Sterile Insect Technique (SIT) can be used to suppress the native populations of Ae. albopictus. Mark-release-recapture (MRR) studies are crucial to support the development of the release strategy during the SIT application. Meanwhile, weather conditions can affect the MRR trial's results and it is critical to understand the influence of climatic factors on the results. In October 2022, 84,000 irradiated sterile males were released for three consecutive weeks in Faro, Southern Portugal. Mosquitoes were recaptured by human landing collection (HLC) one, two, four, and six days after release. Generalized linear models with a negative binomial family and log function were used to estimate the factors associated with the number of recaptured mosquitoes, prevalence ratios, and the 95% confidence intervals (CIs). A total of 84,000 sterile male mosquitoes were released, with 528 recaptured (0.8%) by HLC. The prevalence of recaptured mosquitoes was 23% lower when the wind intensity was moderate. Marked sterile males had an average median distance travelled of 88.7 m. The median probability of daily survival and the average life expectancy were 61.6% and 2.1 days, respectively. The wild male population estimate was 443.33 males/ha. Despite no statistically significant association being found with humidity, temperature, and precipitation, it is important to consider weather conditions during MRR trial analyses to obtain the best determinant estimation and a more efficient application of the SIT in an integrated vector management program.

New Iflavirus Species Characterized from Mosquitoes Captured in the Sao Paulo Zoological Facilities.

Metagenomic studies of mosquito viromes demonstrated a more diverse composition than just an exclusive composition of pathogenic arboviruses transmitted to humans. In our study, the virome of 866 female mosquitoes collected throughout 2020 at the São Paulo Zoo, located in the city of São Paulo/SP-Brazil, was obtained. Specifically, in this paper, we describe a new virus found by viral RNA extraction and next-generation MiSeq sequencing of a group of 23 specimens of Anopheles (Nys.) strodei. The complete genome with a length of 9709 nucleotides was characterized by a positive orientation and a single strand, with a single large ORF, which encodes a polyprotein of 2987 amino acids. The phylogenetic analysis showed an association with the viral family Iflaviridae and the Riboviria realm. We carried out comparisons with translated sequences of the capsid regions of other iflavirus, and the identities in relation to our sequence were below the minimum limit of 90%, indicating that possibly it is a new species of iflavirus. Our findings contribute to expanding knowledge of virome composition among mosquito species in Brazil and globally. Moreover, we provide a viral genome reference specific to this geographic region and Culicidae family of mosquitoes. This resource facilitates future in silico recognition and assembly of viral genomes within metagenomic datasets.

Plasticity of blood feeding behavior of Anopheles mosquitoes in Ethiopia: a systematic review.

BACKGROUND: The efficacy of vector control tools depends on the behavior of the vector species. Many studies have sought to determine the feeding behavior of Anopheles mosquitoes in different settings of Ethiopia. We have performed a systematic review aimed to generate pooled evidence on the overall and species-specific blood meal sources of Anopheles mosquitoes in Ethiopia. METHODS: A search for relevant articles was performed in two electronic databases (PubMed and Science Direct) and three search engines (Google Scholar, Research Gate and Google) between 11 March and 2 April 2024. Following the initial identification of articles, we used EndNote X8 software and removed duplicate articles and screened the remaining articles by careful reading of their titles and abstracts. The full text of articles that passed this screening phase was retrieved, read and evaluated against predetermined selection criteria. The final decision for inclusion in the systematic review was made after a methodological quality check using the JBI critical appraisal checklist. All relevant data were extracted from tables, figures and texts of the included articles using a premade template in Excel, and the data were analyzed using Stata version 14 software. RESULTS: Of the 2431 studies identified, 27 met the inclusion criteria; all were published between 1997 and 2024. At 215 data points (frequency of tests of each Anopheles species by location and method of mosquito collections), 18,771 Anopheles mosquitoes belonging to 23 species or species complexes were tested for blood meal sources. The commonest sources of blood meals for Anopheles mosquitoes were bovine (36.0%, n = 6758) and human (29.4%, n = 5520). Among the tested anophelines, Anopheles (An.) arabiensis accounted for 67.9% (n = 12,741), followed by An. pharoensis, An. demeilloni and An. stephensi at 10.0%, 5.6% and 4.4%, respectively. Overall, there was no difference in the mean proportion of An. arabiensis detected with domestic animal blood (33.4%, 95% confidence interval [CI] 32.4-34.4%) and those detected with human blood (31.8%, 95% CI 30.9-32.8%). However, a greater proportion of the outdoor collected An. arabiensis were found to feed on bovines (47.9%, 95% CI 35.3-60.6) compared to humans (12.9%, 95% CI 0.8-24.9, P < 0.01). The foraging ratio (FR), which accounts for host availability, was greater for bovines (FR = 0.7) than for humans (FR = 0.2) for An. arabiensis, indicating preferential feeding on bovine hosts. This host preference was supported by the host preference index (human:bovine = 0.4). Anopheles pharoensis was detected with a slightly higher human blood index (53.5%, n = 1005) compared to bovine blood index (45.2%, n = 849). In contrast, An. demeilloni, An. coustani and An. marshalli were detected with a higher bovine blood index. Recently invaded urban malaria vector, An. stephensi was found with a higher ovine blood index. CONCLUSIONS: Bovine and human hosts are common sources of a blood meal for Anopheles mosquitoes. In terms of host availability, An. arabiensis showed preferential feeding on bovines/cattle. Targeting domestic animals, bovines and ovines with endectocides could supplement current vector control interventions. STUDY REGISTRATION: The protocol of this study was registered on the International Prospective Register of Systematic Reviews, registration no. CRD42024515725.

The impact of Bacillus thuringiensis var. israelensis (Vectobac® WDG) larvicide sprayed with drones on the bio-control of malaria vectors in rice fields of sub-urban Kigali, Rwanda.

BACKGROUND: The core vector control tools used to reduce malaria prevalence are currently long-lasting insecticidal nets (LLINs), and indoor residual spraying (IRS). These interventions are hindered by insecticide resistance and behavioural adaptation by malaria vectors. Thus, for effective interruption of malaria transmission, there is a need to develop novel vector control interventions and technologies to address the above challenges. Larviciding using drones was experimented as an innovative tool that could complement existing indoor interventions to control malaria. METHODS: A non-randomized larviciding trial was carried out in irrigated rice fields in sub-urban Kigali, Rwanda. Potential mosquito larval habitats in study sites were mapped and subsequently sprayed using multirotor drones. Application of Bacillus thuringiensis var. israelensis (Bti) (Vectobac® WDG) was followed by entomological surveys that were performed every two weeks over a ten-month period. Sampling of mosquito larvae was done with dippers while adult mosquitoes were collected using CDC miniature light traps (CDC-LT) and pyrethrum spraying collection (PSC) methods. Malaria cases were routinely monitored through community health workers in villages surrounding the study sites. RESULTS: The abundance of all-species mosquito larvae, Anopheles larvae and all-species pupae declined by 68.1%, 74.6% and 99.6%, respectively. Larval density was reduced by 93.3% for total larvae, 95.3% for the Anopheles larvae and 61.9% for pupae. The total adult mosquitoes and Anopheles gambiae sensu lato collected using CDC-Light trap declined by 60.6% and 80% respectively. Malaria incidence also declined significantly between intervention and control sites (U = 20, z = - 2.268, p = 0.023). CONCLUSIONS: The larviciding using drone technology implemented in Rwanda demonstrated a substantial reduction in abundance and density of mosquito larvae and, concomitant decline in adult mosquito populations and malaria incidences in villages contingent to the treatment sites. The scaling up of larval source management (LSM) has to be integrated in malaria programmes in targeted areas of malaria transmission in order to enhance the gains in malaria control.

Investigating the impact of climate and seasonality on mosquito (Diptera: Culicidae) vector populations in the connecting areas of the Tenasserim range forests in Thailand.

Mosquito-borne diseases pose a significant public health challenge globally. Our study focused on the seasonal diversity of mosquito species in the connecting areas of the Tenasserim (also known as Tanaosri) range forests in Thailand. Additionally, we employed the geometric morphometric technique to assess variations in wing size and shape among five predominant mosquito species. Throughout the study period, we collected a total of 9,522 mosquitoes, encompassing 42 species across eight genera. In these connecting areas of forests, the Simpson index and Shannon species diversity index were recorded at 0.86 and 2.36, respectively, indicating a high level of mosquito diversity. Our analysis using the Analysis of Similarities (ANOSIM) test showed significant seasonal differences in mosquito communities, with an R-value of 0.30 (p < 0.05) in the lower connecting areas and 0.37 (p < 0.05) in the upper connecting areas. Additionally, canonical correspondence analyses showed that the abundance of each mosquito species is influenced by various climate factors. Phenotypic analyses of wing size and shape have deepened our understanding of local adaptation and the seasonal pressures impacting these vectors. Notably, most species exhibited larger wing sizes in the dry season compared to other seasons. Additionally, seasonal assessments of wing shape in five predominant mosquito species revealed significant differences across seasonal populations (p < 0.05). Ongoing monitoring of these populations is crucial to enhancing our understanding of the seasonal effects on mosquito abundance and physiological adaptations. These insights are essential for developing more effective strategies to manage mosquito-borne diseases.

Aedes albopictus colonies from different geographic origins differ in their sleep and activity levels but not in the time of peak activity.

Mosquitoes occupy a wide range of habitats where they experience various environmental conditions. The ability of some species, such as the tiger mosquito, Aedes albopictus, to adapt to local conditions certainly contributes to their invasive success. Among traits that remain to be examined, mosquitoes' ability to time their activity with that of the local host population has been suggested to be of significant epidemiological importance. However, whether different populations display heritable differences in their chronotype has not been examined. Here, we compared laboratory strains originating from eight populations from three continents, monitored their spontaneous locomotor activity patterns and analysed their sleep-like states. Overall, all strains showed conserved diurnal activity concentrated in the hours preceding the crepuscule. Similarly, they all showed increased sleep levels during the morning and night hours. However, we observed strain-specific differences in the activity levels at each phase of the day. We also observed differences in the fraction of time that each strain spends in a sleep-like state, explained by variations in the sleep architecture across strains. Human population density and the latitude of the site of the geographic origin of the tested strain showed significant effects on sleep and activity patterns. Altogether, these results suggest that Ae. albopictus mosquitoes adapt to local environmental conditions via heritable adaptations of their chronotype.

Enzyme Dynamics Determine the Potency and Selectivity of Inhibitors Targeting Disease-Transmitting Mosquitoes.

Vector control of mosquitoes with insecticides is an important tool for preventing the spread of mosquito-borne diseases including malaria, dengue, chikungunya, and Zika. Development of active ingredients for insecticides are urgently needed because existing agents exhibit off-target toxicity and are subject to increasing resistance. We therefore seek to develop noncovalent inhibitors of the validated insecticidal target acetylcholinesterase 1 (AChE1) from mosquitoes. Here we use molecular dynamics simulations to identify structural properties essential for the potency of reversible inhibitors targeting AChE1 from Anopheles gambiae (AgAChE1), the malaria-transmitting mosquito, and for selectivity relative to the vertebrate Mus musculus AChE (mAChE). We show that the collective motions of apo AgAChE1 and mAChE differ, with AgAChE1 exhibiting less dynamic movement. Opening and closing of the gorge, which regulates access to the catalytic triad, is enabled by different mechanisms in the two species, which could be linked to their differing amino acid sequences. Inhibitor binding reduced the overall magnitude of dynamics of AChE. In particular, more potent inhibitors reduced the flexibility of the Ω loop at the entrance of the gorge. The selectivity of inhibitors for AgAChE1 over mAChE derives from the positioning of the α-helix lining the binding gorge. Our findings emphasize the need to consider dynamics when developing inhibitors targeting this enzyme and highlight factors needed to create potent and selective AgAChE1 inhibitors that could serve as active ingredients to combat disease-transmitting mosquitoes.

Unveiling spatial patterns of West Nile virus emergence in northern Greece, 2010-2023.

The Region of Central Macedonia (RCM) in Northern Greece recorded the highest number of human West Nile virus (WNV) infections in Greece, despite considerable local mosquito control actions. We examined spatial patterns and associations of mosquito levels, infected mosquito levels, and WNV human cases (WNVhc) across the municipalities of this region over the period 2010-2023 and linked it with climatic characteristics. We combined novel entomological and available epidemiological and climate data for the RCM, aggregated at the municipality level and used Local and Global Moran's I index to assess spatial associations of mosquito levels, infected mosquito levels, and WNVhc. We identified areas with strong interdependencies between adjacent municipalities in the Western part of the region. Furthermore, we employed a Generalized Linear Mixed Model to first, identify the factors driving the observed levels of mosquitoes, infected mosquitoes and WNVhc and second, estimate the influence of climatic features on the observed levels. This modeling approach indicates a strong dependence of the mosquito levels on the temperatures in winter and spring and the total precipitation in early spring, while virus circulation relies on the temperatures of late spring and summer. Our findings highlight the significant influence of climatic factors on mosquito populations (∼60 % explained variance) and the incidence of WNV human cases (∼40 % explained variance), while the unexplained ∼40 % of the variance suggests that targeted interventions and enhanced surveillance in identified hot-spots can enhance public health response.

Intra-species quantification reveals differences in activity and sleep levels in the yellow fever mosquito, Aedes aegypti.

Aedes aegypti is an important mosquito vector of human disease with a wide distribution across the globe. Climatic conditions and ecological pressure drive differences in the biology of several populations of this mosquito species, including blood-feeding behaviour and vector competence. However, no study has compared activity and/or sleep among different populations/lineages of Ae. aegypti. Having recently established sleep-like states in three mosquito species with observable differences in timing and amount of sleep among species, we investigated differences in activity and sleep levels among 17 Ae. aegypti lines drawn from both its native range in Africa and its invasive range across the global tropics. Activity monitoring indicates that all the lines show consistent diurnal activity, but significant differences in activity level, sleep amount, number of sleep bouts and bout duration were observed among the lines. The variation in day activity was associated with differences in host preference and ancestry for the lineages collected in Africa. This study provides evidence that the diurnal sleep and activity profiles for Ae. aegypti are consistent, but there are significant population differences for Ae. aegypti sleep and activity levels and interactions with host species may significantly impact mosquito activity.

Sylvatic Mosquito Viromes in the Cerrado Biome of Minas Gerais, Brazil: Discovery of New Viruses and Implications for Arbovirus Transmission.

Studies on animal virome have mainly concentrated on chordates and medically significant invertebrates, often overlooking sylvatic mosquitoes, constituting a major part of mosquito species diversity. Despite their potential role in arbovirus transmission, the viromes of sylvatic mosquitoes remain largely unexplored. These mosquitoes may also harbor insect-specific viruses (ISVs), affecting arboviral transmission dynamics. The Cerrado biome, known for rapid deforestation and its status as a biodiversity hotspot, offers an ideal setting for investigating mosquito viromes due to potential zoonotic spillover risks from land use changes. This study aimed to characterize the viromes of sylvatic mosquitoes collected from various locations within Minas Gerais state, Brazil. The total RNA was extracted from mosquito pools of Psorophora albipes, Sabethes albiprivus, Sa. chloropterus, Psorophora ferox, and Coquillettidia venezuelensis species, followed by high-throughput sequencing (HTS). Bioinformatic analysis included quality control, contig assembly, and viral detection. Sequencing data analysis revealed 11 near-complete viral genomes (new viruses are indicated with asterisks) across seven viral families and one unassigned genus. These included: Xinmoviridae (Ferox mosquito mononega-like virus* and Albipes mosquito Gordis-like virus*), Phasmaviridae (Sabethes albiprivus phasmavirus*), Lispiviridae (Pedras lispivirus variant MG), Iflaviridae (Sabethes albiprivus iflavivirus*), Virgaviridae (Buriti virga-like virus variant MG and Sabethes albiprivus virgavirus 1*), Flaviviridae (Psorophora ferox flavivirus*), Mesoniviridae (Alphamesonivirus cavallyense variant MG), and the genus Negevirus (Biggie virus variant MG virus and Coquillettidia venezuelensis negevirus*). Moreover, the presence of ISVs and potential novel arboviruses underscores the need for ongoing surveillance and control strategies to mitigate the risk of emerging infectious diseases.