A promising approach to expanding the reach of citizen science-based mosquito surveillance is collaborating with partners such as GLOBE (est. 1995), an international organization created through bilateral country agreements with the US Department of State. Specifically, NASA’s GLOBE Observer mobile app (observer.globe.gov) is available for use in 127 countries and has been translated into 15 languages. The GLOBE program has a long track record of engaging students and citizen scientists, with more than 200 million observations logged since 1995 (Amos et al. 2020; Low et al. 2022). User-provided data includes information on and photos of mosquito larvae, pupae, and breeding habitats collected using the Mosquito Habitat Mapper tool. Through the Land Cover tool, ecological information and photos are collected, which can complement the mosquito data in subsequent analyses; participants are prompted through the app to take such coincident observations after using the Mosquito Habitat Mapper tool.

Historically, creation of the Mosquito Habitat Mapper tool was stimulated by the GLOBE community in Africa, who developed the initial protocol for local use in the 1990s. This work was then incorporated into the GLOBE Program as a scientifically vetted international protocol in 2014. The digital app was codeveloped with GLOBE partners in Thailand and Africa in 2016, and was first tested in partnership with communities in Peru and Brazil in 2017, in response to the previous year’s epidemic of Zika. The app particularly targeted the vectors of that disease, Aedes (Ae.) aegypti and Ae. albopictus. In Africa, GLOBE citizen science has provided actionable data for mosquito control, for example by demonstrating that the most frequent oviposition sites vary among three communities in Senegal (Low et al. 2021). In Latin America, access to and use of citizen science data collection apps have proved to be motivating, especially for adolescents, and the Cooperative for Assistance and Relief Everywhere’s “Juntos ante el Zika” (Together Fighting Against Zika) project incorporated GLOBE Observer Mosquito Habitat Mapper training and use into youth-led community mosquito-awareness programs. Internationally, behavioral data collected using the GLOBE Observer Mosquito Habitat Mapper app has shown that the majority of citizen scientists who collected data were also motivated to reduce the availability of breeding sites by removing, draining, or covering water containers where possible (Low et al. 2021).

Mosquito Alert (mosquitoalert.com) is an international citizen science project involving the submission of photos of adult mosquitoes as well as information on mosquito bites and breeding habitats (Figure 2a). The app has been translated into 19 languages, including languages broadly spoken in Africa, such as French and English. The app provides instructions on taking the mosquito photos so they are suitable for species identification and subsequent expert validation (e.g., “Try to photograph the mosquito so that the markings on its thorax and legs can be seen;” https://www.mosquitoalert.com/en/project/envia-datos/tips-for-your-photos/). As a form of gamification to incentivize participation, citizen scientists are awarded points based on the type of mosquito and breeding site reported, as well as extra bonuses for actions such as participating frequently. The accumulation of points allows users to reach five different levels and be placed on a leaderboard with global rankings of users. There are also trophies based on various milestones. In addition, Mosquito Alert has created customized management portals and alerts, for communicating directly with agencies and users (Bartumeus et al. 2018), as well as data-visualization tools such as vector risk maps (e.g., https://labs.mosquitoalert.com/MosquitoAlertES/).

Since its inception in 2014, Mosquito Alert has demonstrated how citizen scientist action has improved understanding of the movement and location of vector species in Spain, compared with that of municipal mosquito control programs alone (Palmer et al. 2017). It is often the case that participants do not send pictures of targeted species but of similar ones or of species that are strange to them. Indeed, the discovery of Ae. japonicus in the north of Spain in 2018 has demonstrated that citizen scientists can report species of public health interest other than the species identified a priori by scientists (Eritja et al. 2019; Eritja et al. 2021). Ae. japonicus was not included in the initial versions of Mosquito Alert deployed in the country because, contrary to the information on Ae. aegypti, there were no previous records of this species in Spain. Ae. japonicus appeared for the first time in 2000 in eastern France, and dispersed to Belgium, Switzerland, and Germany (2008), and from there to other northern and eastern European countries (Austria, Slovenia, Netherlands, Hungary, Croatia), to finally appear in Italy and Liechtenstein in 2015. The 2018 discovery reported by a Mosquito Alert participant in the north of Spain was validated in the field by the Spanish Ministry of Health, enhanced further citizen-based monitoring, and activated different field surveillance strategies by experts in the area (Eritja et al. 2021). In addition, the species was added as one of the target species in the citizen science-based system.

There are plans for Mosquito Alert to redesign its data collection system to include, among other new features, the genus Anopheles, so as to better fight malaria in Africa. Even if An. stephensi is not explicitly included in the app’s mosquito guide, initiating deployments of the app in Africa would be useful.

The social networking platform iNaturalist (inaturalist. org) is available via mobile app and web browser and in more than 50 languages, including Arabic, French, and Portuguese. Users submit photos (or sound recordings) of wild organisms, along with a date and location data. These organisms are then identified by other users, and at least two-thirds of these crowdsourced taxonomic classifications must agree for the record to be designated as “Research Grade.” (To date, only one Research Grade observation of An. stephensi exists on the iNaturalist platform, which was recorded in Kuwait in November 2021). Users can also subscribe to taxa, locations, and other users, which provides daily updates on submissions of interest and thus a means of monitoring natural populations.

Further platform engagement and promotion can occur through coordinated “bioblitzes,” which are community events targeting one or more species at a given location for a short period, or through project pages that cover larger geographic areas and/or longer spans of time, and include leaderboards for the number of observations and identifications (Figure 3). Our previous efforts on this platform have included various targeted citizen science campaigns in the Americas (mosquitoAI.org), which yielded detections of invasive vector mosquitoes in new areas (Carney et al. 2022) and validation data for a mosquito habitat model (Uelmen et al. 2023). More recently, we have launched a campaign in Africa focused on An. stephensi (mosquitoesinAfrica.org; Figure 3). These observations have already led to the discovery of a previously undocumented phenomenon, mosquito bite-induced color change in chameleon skin (Garcia et al., in revision), demonstrating the utility and serendipity of citizen science observations.

These successes observed in local and regional citizen science surveillance projects suggest the importance of collaboration in the scientific community to make data, tools, and expertise available worldwide. This is especially true for low-resource communities that can benefit from the use of ready-made, widely available data collection apps, a cloud-based archive, and open-source analysis tools developed for the greater good by others and available at no cost.

This was the vision behind the creation of GMAC. Hosted by the Woodrow Wilson International Center for Scholars (Wilson Center), the European Citizen Science Association (ECSA), and the United Nations Environment Programme, representatives from seven citizen science programs focused on mosquito surveillance convened in 2017 to envision an inclusive international effort to support mosquito surveillance and mitigation (Tyson et al. 2018; Palmer et al. 2018). The expressed goal of this project was to provide a digital infrastructure that could harness rapidly emerging open-data tools and capabilities, together with mosquito data from across the globe. Subsequent to this meeting, significant steps have been made to make this vision a reality.

Through a GMAC collaboration, multiple international citizen science platforms—Mosquito Alert, Mosquito Habitat Mapper, Land Cover, and iNaturalist—were aligned to the Open Geospatial Consortium data interoperability standards (Ingle et al. 2021) and harmonized into the Global Mosquito Observations Dashboard (GMOD; mosquitodashboard.org; Figure 4; Carney et al. 2022). With this open and findable, accessible, interoperable, and reusable (FAIR) infrastructure now in place, it is possible to promote worldwide participation in mosquito surveillance to better meet scientific and public health goals. The large and increasing number of observations displayed on the GMOD (~300 K at time of print) highlights the already-established international usage of these apps for tracking mosquito populations.

This work was conducted across multiple research organizations, private collaborators, and government entities, including the University of South Florida, the Wilson Center, the US Department of State, the Institute for Global Environmental Strategies, Universitat Pompeu Fabra, Spanish National Research Council, NASA, iNaturalist, and many more. The sheer breadth of collaborators involved in this work should indicate how the integration of even relatively similar citizen science projects takes ample resources, international partnerships, and time. GMAC and its products are realizing the vision of empowering decentralized, local citizen science communities with open tools. These tools enable a broad cross-section of the world’s citizens to contribute to mosquito monitoring and public health in their own communities and to play a role in the global fight against diseases transmitted by mosquitoes.

We therefore recommend that investment go toward building national and local infrastructure for citizen science networks focused on An. stephensi and malaria surveillance, including hiring community health workers, supplying materials (mobile devices, lenses, etc.), and supporting promotional campaigns (see below). Such crowd-sourced mosquito surveillance is a neglected but scalable and cost-effective solution, given its relatively low cost and non-recurring investments (Palmer et al. 2017). This recommendation is, of course, in addition to a call for greater investment in malaria control and elimination in Africa in general, as the gap between resource need and funding has dramatically widened over recent years to $3.8 billion in 2021 (WHO 2022b). Much of this support will need to come from international sources, from which 67% of total malaria funding was provided between 2010 and 2021 (WHO 2022b). Additionally, and with an eye toward building national capacities over the longer term, we echo the recommendation for some debt forgiveness for those countries investing in research and development (Nature 2023), particularly on issues of malaria, SDGs 6 and 11, and energy.

Indeed, one fundamental challenge is that access to electricity is lacking for a staggering 43% of the continent’s population, approximately 600 million people (World Bank 2023). Another bottleneck includes the availability of devices necessary to download the 16–66 MB apps or to access GMOD and mosquitoID.org via the browser. This is especially true in low-resource and remote regions. In communities with low smartphone penetration, one recommendation is that a community health worker(s) be equipped with a smartphone or tablet. Through door-to-door or other campaigns, they could take photos of Anopheles mosquitoes on behalf of others in the community without a smartphone, and then submit the observations through the appropriate app (or upload photos from other individuals that have a camera).

Generally, however, smartphones are increasing in use, especially in urban areas where An. stephensi is expected to have the greatest introduction and impact. In Sub-Saharan Africa alone, there were over half a billion smartphone subscriptions in 2021, and this number is expected to reach 800 million by 2027 (statista.com 2022). Smartphones there represent approximately half of total internet connections, and mobile data consumption is expected to nearly quadruple by 2027 (Global System for Mobile Communications 2022).

Another critical bottleneck is the lack of access to magnification devices such as the 60× clip-on lenses for smartphones, which are required for imaging mosquito larvae (or diagnostic features for manual identification of An. stephensi, Figure 1). While to date our USF team has supplied more than 1,500 of these lenses to 18 African countries for the purpose of An. stephensi larval surveillance, these shipments take weeks to months, and some have been lost in transit. Alternative devices such as a high-powered hand magnifying glass, a microscope, or even reversed binoculars may serve to fill this need.

Community outreach and educational resources that can be used to expand the reach of citizen science mosquito monitoring programs are available from several sources, including Mosquito Habitat Mapper (https://observer.globe.gov/toolkit/mosquito-habitat-mapper-toolkit) and Mosquito Alert (https://www.mosquitoalert.com). It should also be noted that there are offline versions of many projects that could be deployed in areas with low or no broadband access. Several mobile apps for data reporting, such as Mosquito Habitat Mapper, do not need internet access to collect data; a signal is needed only to upload data to the digital archive. If citizen scientists are reluctant to use their personal credits for uploading such data, partnerships with local internet cafes or other establishments may provide a viable solution.

Similarly, data collection campaigns are most likely to be successful when strong partnerships are developed with local education, health, and touristic organizations, and where data collection can serve as a positive addition to existing programmatic goals. This is because even when the proper software, hardware, and educational resources are accessible, other bottlenecks and challenges can exist, such as training participants as well as sustaining their motivation to collect data. Community mobilization in urban areas is necessary to raise awareness of the problem and to foster the use of simple tools geared toward the identification of An. stephensi, such as 60× lenses coupled with our identification guide (Figure 1).

Concerted efforts should be made by stakeholders to recruit and mobilize app superusers and community health workers, and equip the latter with smartphones and lenses. With respect to community outreach and education surrounding such efforts, it would be prudent to leverage and scale existing networks such as school districts and scouting groups. It will also be strategic to repurpose existing arboviral surveillance programs—especially those targeting other container-breeding mosquitoes such as Ae. aegypti and Ae. albopictus, as was done for An. stephensi in Mauritius (Iyaloo et al. 2022). In particular, the Pan-African Mosquito Control Association (PAMCA; pamca.org) and the West African Aedes Surveillance Network (WAASuN; waasun.org) have Aedes surveillance programs that could be utilized, and perhaps coordinated and integrated with citizen scientist networks. Such integrated surveillance would align with the WHO Global Vector Control Response strategy (WHO 2017). Indeed, mosquito control agencies will be critical in mounting appropriate responses to An. stephensi, and their efforts could include monitoring and contributing to the GMOD. Additionally, gaps in the GMOD’s data in Africa reveal areas for targeting intervention from groups like CitSci Africa to promote as new places for citizen science uptake. These mobilization steps will help greatly in the surveillance stage, and if successful for a given area, can be scaled up rapidly to other parts of the continent.

To greatly assist in scaling up mobilization efforts, promotional campaigns are also encouraged at the local, regional, and national levels. One such success story involves a national event on mainstream television and radio in the Netherlands on July 22, 2021, through which public figures urged citizens to use the Mosquito Alert app to help detect invasive Aedes species, and to a lesser extent, report bites. This led to an unprecedented surge in reports of mosquito adults and bites, which increased over 1,000-fold and 500-fold (5 versus 5.2 K adults, and 5 versus 2.7 K bites) in the week after the event compared with the week prior, with increased reporting observed through November 2021 (mosquitodashboard.org; reports without time/location data are omitted). If similar mosquito-targeted calls-to-action and mobilization could be achieved in African nations, it would certainly cast a much wider and denser net with which to catch An. stephensi—especially compared with traditional trapping methods. It would also have the benefit of increasing public education and awareness of this invasive vector and of malaria in general. Furthermore, such messaging would likely be efficient and cost-effective, given that media reach, smartphone penetration, and network effects of citizen scientists are all greatest in urban areas, exactly where this mosquito thrives.

Too often, projects created in the US and Europe fail to include voices from Africa, Central and South America, and Asia, an especially critical oversight when those are the countries where such tools are needed the most. Those blind spots in the initial project structure’s lack of representation can be ameliorated through deliberate inclusion and engagement with stakeholders and research partners from a truly international community, concerted collaboration with global mosquito tracking apps, and capacity-building efforts at the local grassroots level. Strengthening the partnership between groups like GMAC and CitSci Africa may be the most important first step to facilitating the transfer of such research knowledge (CitSci Africa 2021). Furthermore, for the citizen science infrastructure that already exists, such as the mobile apps and educational resources, it will be important to add African languages to better engage the necessary communities and to increase inclusivity. In particular, this involves translation into Swahili, which our group has recently completed.

It is important to communicate to citizen scientists not just the public health utility of the data being collected (Fischer et al. 2021), but also the necessity of testing any specimens that are suspected to be An. stephensi in a new area. Since 2020, the Mosquito Alert app has included instructions for mailing adult mosquito specimens to reference laboratories in selected countries, and this could be extended to any facility in Africa willing to participate. Through this process, users are notified through the app if they are in a country with laboratories actively accepting specimens (Figure 2). Such notifications could be sent only to those users submitting photos of Anopheles or unknown mosquitoes, and/or based on specific months or resource availability. It is worth noting that this strategy of having participants mail in mosquito specimens has been employed by at least a dozen other citizen science programs (Sousa et al. 2022). At present, full sequencing is the gold standard and the only acceptable method, as opposed to other methods such as polymerase chain reaction (Singh et al. 2023), for confirming An. stephensi in a new area (WHO 2023b). Until local testing capacity or other submission pipelines are developed, there will remain a critical bottleneck for the confirmation of An. stephensi in new areas and the deployment of necessary responses.