Recent outbreaks of Zika, chikungunya and dengue highlight the importance of better understanding the spread of disease-carrying mosquitoes across multiple spatio-temporal scales. Traditional surveillance tools are limited by jurisdictional boundaries and cost constraints. Here we show how a scalable citizen science system can solve this problem by combining citizen scientists’ observations with expert validation and correcting for sampling effort. Our system provides accurate early warning information about the Asian tiger mosquito (Aedes albopictus) invasion in Spain, well beyond that available from traditional methods, and vital for public health services. It also provides estimates of tiger mosquito risk comparable to those from traditional methods but more directly related to the human–mosquito encounters that are relevant for epidemiological modelling and scalable enough to cover the entire country. These results illustrate how powerful public participation in science can be and suggest citizen science is positioned to revolutionize mosquito-borne disease surveillance worldwide.

The growing capacity to process and store animal tracks has spurred the development of new methods to segment animal trajectories into elementary units of movement. Key challenges for movement trajectory segmentation are to (i) minimize the need of supervision, (ii) reduce computational costs, (iii) minimize the need of prior assumptions (e.g. simple parametrizations), and (iv) capture biologically meaningful semantics, useful across a broad range of species. We introduce the Expectation-Maximization binary Clustering (EMbC), a general purpose, unsupervised approach to multivariate data clustering. The EMbC is a variant of the Expectation-Maximization Clustering (EMC), a clustering algorithm based on the maximum likelihood estimation of a Gaussian mixture model. This is an iterative algorithm with a closed form step solution and hence a reasonable computational cost. The method looks for a good compromise between statistical soundness and ease and generality of use (by minimizing prior assumptions and favouring the semantic interpretation of the final clustering). Here we focus on the suitability of the EMbC algorithm for behavioural annotation of movement data. We show and discuss the EMbC outputs in both simulated trajectories and empirical movement trajectories including different species and different tracking methodologies. We use synthetic trajectories to assess the performance of EMbC compared to classic EMC and Hidden Markov Models. Empirical trajectories allow us to explore the robustness of the EMbC to data loss and data inaccuracies, and assess the relationship between EMbC output and expert label assignments. Additionally, we suggest a smoothing procedure to account for temporal correlations among labels, and a proper visualization of the output for movement trajectories. Our algorithm is available as an R-package with a set of complementary functions to ease the analysis.

The recent emergence in Europe of invasive mosquitoes and mosquito-borne disease associated with both invasive and native mosquito species has prompted intensified mosquito vector research in most European countries. Central to the efforts are mosquito monitoring and surveillance activities in order to assess the current species occurrence, distribution and, when possible, abundance, in order to permit the early detection of invasive species and the spread of competent vectors. As active mosquito collection, e.g. by trapping adults, dipping preimaginal developmental stages or ovitrapping, is usually cost-, time- and labour-intensive and can cover only small parts of a country, passive data collection approaches are gradually being integrated into monitoring programmes. Thus, scientists in several EU member states have recently initiated programmes for mosquito data collection and analysis that make use of sources other than targeted mosquito collection. While some of them extract mosquito distribution data from zoological databases established in other contexts, community-based approaches built upon the recognition, reporting, collection and submission of mosquito specimens by citizens are becoming more and more popular and increasingly support scientific research. Based on such reports and submissions, new populations, extended or new distribution areas and temporal activity patterns of invasive and native mosquito species were found. In all cases, extensive media work and communication with the participating individuals or groups was fundamental for success. The presented projects demonstrate that passive approaches are powerful tools to survey the mosquito fauna in order to supplement active mosquito surveillance strategies and render them more focused. Their ability to continuously produce biological data permits the early recognition of changes in the mosquito fauna that may have an impact on biting nuisance and the risk of pathogen transmission associated with mosquitoes. International coordination to explore synergies and increase efficiency of passive surveillance programmes across borders needs to be established.

BackgroundAedes japonicus is an invasive vector mosquito from Southeast Asia which has been spreading across central Europe since the year 2000. Unlike the Asian Tiger mosquito (Aedes albopictus) present in Spain since 2004, there has been no record of Ae. japonicus in the country until now.ResultsHere, we report the first detection of Ae. japonicus in Spain, at its southernmost location in Europe. This finding was triggered by the citizen science platform Mosquito Alert. In June 2018, a citizen sent a report via the Mosquito Alert app from the municipality of Siero in the Asturias region (NW Spain) containing pictures of a female mosquito compatible with Ae. japonicus. Further information was requested from the participant, who subsequently provided several larvae and adults that could be classified as Ae. japonicus. In July, a field mission confirmed its presence at the original site and in several locations up to 9 km away, suggesting a long-time establishment. The strong media impact in Asturias derived from the discovery raised local participation in the Mosquito Alert project, resulting in further evidence from surrounding areas.ConclusionsWhilst in the laboratory Ae. japonicus is a competent vector for several mosquito-borne pathogens, to date only West Nile virus is a concern based on field evidence. Nonetheless, this virus has yet not been detected in Asturias so the vectorial risk is currently considered low. The opportunity and effectiveness of combining citizen-sourced data to traditional surveillance methods are discussed.

Traditional methods for tracking disease-carrying mosquitoes are hitting budget constraints as the scales over which they must be implemented grow exponentially. Citizen science offers a novel solution to this problem but requires new models of innovation in the public health sector.

Human mobility is becoming an accessible field of study, thanks to the progress and availability of tracking technologies as a common feature of smart phones. We describe an example of a scalable experiment exploiting these circumstances at a public, outdoor fair in Barcelona (Spain). Participants were tracked while wandering through an open space with activity stands attracting their attention. We develop a general modelling framework based on Langevin dynamics, which allows us to test the influence of two distinct types of ingredients on mobility: reactive or context-dependent factors, modelled by means of a force field generated by attraction points in a given spatial configuration and active or inherent factors, modelled from intrinsic movement patterns of the subjects. The additive and constructive framework model accounts for some observed features. Starting with the simplest model (purely random walkers) as a reference, we progressively introduce different ingredients such as persistence, memory and perceptual landscape, aiming to untangle active and reactive contributions and quantify their respective relevance. The proposed approach may help in anticipating the spatial distribution of citizens in alternative scenarios and in improving the design of public events based on a facts-based approach.

By modifying how critical ecosystem functions are distributed across the landscape, the spatial configuration and characteristics of patches can play a strong role in structuring communities. In strongly predator‐controlled ecosystems, this patchy distribution of function can have complex downstream consequences, subjecting some areas to disproportionately high rates of predation, leaving other areas susceptible to herbivore outbreaks. In this study, we assess how spatial attributes at patch and landscape scales potentially influence the spatial and temporal distribution of predation on a functionally important herbivore in a patchy Mediterranean marine macrophyte community characterized by strong top‐down control. We experimentally tracked how predation risk of tethered sea urchins varied across space over a 10‐day period in a patchy seagrass meadow. We related these patterns with patch and landscape‐level attributes across the habitat mosaic. At the level of the patch, predation risk was the highest in seagrass patches with low canopies, without access to sheltering rocks. Scaling up to the landscape mosaic however, predation risk increased in dense aggregations of patches with high perimeter‐to‐area ratios close to rocky habitats. Predation aggregated in spatially explicit hotspots and coldspots that were maintained through time. Interestingly, this pattern of predation risk correlated well with the natural abundance of sea urchins. Our results show that spatial patch configuration can be a strong mediator of top trophic functions in marine ecosystems, causing significant clumping in the way predation—and therefore herbivory—are distributed across space. Given the importance of top‐down control for these shallow marine ecosystems, it is crucial to incorporate landscape attributes in understanding the impact of functionally important herbivores on highly fragmented habitats. A http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12985/suppinfo is available for this article.

This chapter describes AtrapaelTigre.com, a citizen science project focusing on the Asian tiger mosquito in Spain. Commonly known for its aggressive biting during the day, the tiger mosquito represents a global environmental problem. It is an invasive species and a vector for dengue, chikungunya and other diseases, making it a serious public health risk. It is also an everyday nuisance and a threat to tourism and related industries. The management of invasive species, and particularly disease vectors, requires integrated programs that combine public communication and education with research, surveillance and control. AtrapaelTigre.com aims at achieving this by engaging citizen scientists to raise awareness and collect data on tiger mosquito adults and their breeding sites with a smartphone app (Tigatrapp) and a multi-proxy data validation system that combines expert, crowd, and app-user input. Lessons learned during the first year of implementation in Spain, in 2014, have guided our current strategies with respect to both tiger mosquitoes and the formal integration of citizen 296 European Handbook of Crowdsourced Geographic Information science into the research, surveillance and control of invasive species and disease vectors generally. We address the challenges of implementing such frameworks and discuss their fitness for use in public health systems. The goal of AtrapaelTigre.com is not only to enhance participation and raise awareness, but also to promote novel research and a more informed and cost-effective management of the tiger mosquito across Spain.