dynamAedes: a unified modelling framework for invasive Aedes mosquitoes

Mosquito species belonging to the genus Aedes have attracted the interest of scientists and public health officers because of their capacity to transmit viruses that affect humans. Some of these species were brought outside their native range by means of trade and tourism and then colonised new regions thanks to a unique combination of eco-physiological traits. Considering mosquito physiological and behavioural traits to understand and predict their population dynamics is thus a crucial step in developing strategies to mitigate the local densities of invasive Aedes populations. Here, we synthesised the life cycle of four invasive Aedes species (Ae. aegypti, Ae. albopictus, Ae. japonicus and Ae. koreicus) in a single multi-scale stochastic modelling framework which we coded in the R package dynamAedes. We designed a stage-based and time-discrete stochastic model driven by temperature, photo-period and inter-specific larval competition that can be applied to three different spatial scales: punctual, local and regional. These spatial scales consider different degrees of spatial complexity and data availability by accounting for both active and passive dispersal of mosquito species as well as for the heterogeneity of the input temperature data. Our overarching aim was to provide a flexible, open-source and user-friendly tool rooted in the most updated knowledge on the species’ biology which could be applied to the management of invasive Aedes populations as well as to more theoretical ecological inquirie

Spatial scale influences the distribution of viral diversity in the eukaryotic virome of the mosquito Culex pipiens

Our knowledge of the diversity of eukaryotic viruses has recently undergone a massive expansion. This diversity could infuence host physiology through yet unknown phenomena of potential interest to the felds of health and food production. However, the assembly processes of this diversity remain elusive in the eukaryotic viromes of terrestrial animals. This situation hinders hypothesis-driven tests of virome infuence on host physiology. Here, we compare taxonomic diversity between different spatial scales in the eukaryotic virome of the mosquito Culex pipiens. This mosquito is a vector of human pathogens worldwide. The experimental design involved sampling in fve countries in Africa and Europe around the Mediterranean Sea and large mosquito numbers to ensure a thorough exploration of virus diversity. A group of viruses was found in all countries. This core group represented a relatively large and diverse fraction of the virome. However, certain core viruses were not shared by all host individuals in a given country, and their infection rates fuctuated between countries and years. Moreover, the distribution of coinfections in individual mosquitoes suggested random co-occurrence of those core viruses. Our results also suggested differences in viromes depending on geography, with viromes tending to cluster depending on the continent. Thus, our results unveil that the overlap in taxonomic diversity can decrease with spatial scale in the eukaryotic virome of C. pipiens. Furthermore, our results show that integrating contrasted spatial scales allows us to identify assembly patterns in the mosquito virome. Such patterns can guide future studies of virome infuence on mosquito physiology.This work was supported by the 7th Framework Programme of the European Commission (grant FP7-613996 Vmerge), the Montpellier University of Excellence Program (MUSE, ArboSud project), and the Direction Générale de l’Alimentation from the French Ministry of Agriculture and Food (DGAl grant agreement: SPA17 n0079-E). The contents of this publication are the sole responsibility of the authors and do not necessarily refect the views of the European Commission.info:eu-repo/semantics/publishedVersio

Anophelines biology in Camargue - France

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Dynamics of prevalence and diversity of avian malaria infections in wild Culex pipiens mosquitoes: the effects of Wolbachia, filarial nematodes and insecticide resistance

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Ecology of West Nile virus across four European countries: empirical modelling of the Culex pipiens abundance dynamics as a function of weather

International audienceBACKGROUND:Culex pipiens is the major vector of West Nile virus in Europe, and is causing frequent outbreaks throughout the southern part of the continent. Proper empirical modelling of the population dynamics of this species can help in understanding West Nile virus epidemiology, optimizing vector surveillance and mosquito control efforts. But modelling results may differ from place to place. In this study we look at which type of models and weather variables can be consistently used across different locations.METHODS:Weekly mosquito trap collections from eight functional units located in France, Greece, Italy and Serbia for several years were combined. Additionally, rainfall, relative humidity and temperature were recorded. Correlations between lagged weather conditions and Cx. pipiens dynamics were analysed. Also seasonal autoregressive integrated moving-average (SARIMA) models were fitted to describe the temporal dynamics of Cx. pipiens and to check whether the weather variables could improve these models.RESULTS:Correlations were strongest between mean temperatures at short time lags, followed by relative humidity, most likely due to collinearity. Precipitation alone had weak correlations and inconsistent patterns across sites. SARIMA models could also make reasonable predictions, especially when longer time series of Cx. pipiens observations are available.CONCLUSIONS:Average temperature was a consistently good predictor across sites. When only short time series (~ 4 years) are available, SARIMAs can provide better statistical descriptions of Cx. pipiens dynamics, without the need for further weather variables. This suggests that density dependence is also an important determinant of Cx. pipiens dynamics

Ecology of West Nile virus across four European countries: review of weather profiles, vector population dynamics and vector control response

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Comparing sterile male releases and other methods for integrated control of the tiger mosquito in temperate and tropical climates

International audienceThe expansion of mosquito species worldwide is creating a powerful network for the spread of arboviruses. In addition to the destruction of breeding sites (prevention) and mass trapping, methods based on the sterile insect technique (SIT), the autodissemination of pyriproxyfen (ADT), and a fusion of elements from both of these known as boosted SIT (BSIT), are being developed to meet the urgent need for effective vector control. However, the comparative potential of these methods has yet to be explored in different environments. This is needed to propose and integrate informed guidelines into sustainable mosquito management plans. We extended a weather-dependent model of Aedes albopictus population dynamics to assess the effectiveness of these different vector control methods, alone or in combination, in a tropical (Reunion island, southwest Indian Ocean) and a temperate (Montpellier area, southern France) climate. Our results confirm the potential efficiency of SIT in temperate climates when performed early in the year (mid-March for northern hemisphere). In such a climate, the timing of the vector control action was the key factor in its success. In tropical climates, the potential of the combination of methods becomes more relevant. BSIT and the combination of ADT with SIT were twice as effective compared to the use of SIT alone

A Case for Systematic Quality Management in Mosquito Control Programmes in Europe

The recent spread of invasive mosquito species, such as Aedes albopictus and the seasonal sporadic transmission of autochthonous cases of arboviral diseases (e.g., dengue, chikungunya, Zika) in temperate areas, such as Europe and North America, highlight the importance of effective mosquito-control interventions to reduce not only nuisance, but also major threats for public health. Local, regional, and even national mosquito control programs have been established in many countries and are executed on a seasonal basis by either public or private bodies. In order for these interventions to be worthwhile, funding authorities should ensure that mosquito control is (a) planned by competent scientific institutions addressing the local demands, (b) executed following the plan that is based on recommended and effective methods and strategies, (c) monitored regularly by checking the efficacy of the implemented actions, (d) evaluated against the set of targets, and (e) regularly improved according to the results of the monitoring. Adherence to these conditions can only be assured if a formal quality management system is adopted and enforced that ensures the transparency of effectiveness of the control operation. The current paper aims at defining the two components of this quality management system, quality assurance and quality control for mosquito control programs with special emphasis on Europe, but applicable over temperate areas

Additional file 1 of dynamAedes: a unified modelling framework for invasive Aedes mosquitoes

Additional file 1: Figure S1. Overview of the temperature-dependent functions used in the model for the four Aedes species. Figure S2. Overview of the temperature-dependent functions used in the model for Ae. aegypti. Figure S3. Overview of the temperature-dependent functions used in the model for Ae. albopictus. Figure S4. Overview of the temperature-dependent functions used in the model for Ae. japonicus. Figure S5. Overview of the temperature-dependent functions used in the model for Ae. koreicus. Figure S6. Overview of the photoperiod-dependent diapause function used to in the model for Ae. albopictus and Ae. japonicus. The Ae. japonicus function was used forAe. koreicus as well. Figure S7. Sensitivity analysis on the effect of (A) the variability of introduced propagules and juvenile-habitat water volume on the percentage of successful introduction; (B) the variability of the juvenile-habitat water volume on the median individual abundance. Figure S8. Predicted percentage of establishment of Ae. aegypti, Ae. albopictus in California (USA) for the years 2011–2016 and 2013–2018, respectively. Only pixels having a probability of successful introduction > 0 are shown. The red dots represent the counties where the species have been found. Table S1. Description of mechanistic models for invasive Aedes available as software or scripts (online or on request). Table S2. Other model features. Table S3. Species-specific temperature-dependent physiological parameters. Table S4. Species-specific dispersal parameters.Table S5. Species-specific photoperiod parameters. Table S6. Validation for Ae. koreicus model in Trento (NE Italy)