In our ongoing efforts to enhance mosquito surveillance and early warning systems, the E4Warning consortium is leveraging innovative technologies, including the improvement of the IRIDEON SL smart-traps. These smart-traps are designed to automate and improve the efficiency of mosquito monitoring, addressing the challenges faced by traditional methods.

Overcoming Traditional Surveillance Challenges

Traditional mosquito surveillance methods are costly and time-consuming, requiring significant professional resources for trap placement, sample collection, and laboratory analysis. Additionally, there is an inevitable time lag between placing traps and collecting samples, which can lead to inaccurate and untimely monitoring of mosquito populations.

The IRIDEON smart traps are off-the-shelf commercial suction traps equipped with the VECTRACK optoelectronic sensor prototype developed by IRIDEON SL in Barcelona. These sensors are capable of distinguishing between mosquito species, sex, and age under both laboratory and field conditions. The VECTRACK sensor includes an emitter, an array of LEDs, and photo-transistors acting as photoreceptors, all working together to create a light field. When a mosquito is drawn into the trap, its wing flapping modulates the light field, generating a species-specific signature. This signature is processed using AI methods, including rule-based systems, genetic algorithms, artificial neural networks, and fuzzy models, to classify the mosquito by genus, species, sex, and age.

Each VECTRACK recording includes GPS coordinates, date and time of capture, ambient temperature, and relative humidity. Every 30 minutes, the field sensor transmits data batches to the server via the mobile phone network. The server then classifies each mosquito event, providing detailed and accurate data on mosquito populations in real-time. This automation reduces the need for manual intervention and enables continuous monitoring.

Field Performance and Global Testing

The VECTRACK sensor has demonstrated its effectiveness in real-world scenarios, achieving high accuracy in field trials conducted in Spain. In El Prat de Llobregat (2021) and Rubí (2022), the sensor achieved 95.5% accuracy in species detection and 88.8% accuracy in classifying the genus and sex of mosquitoes. Check the work performed by Gozález-Pérez et al.: Field evaluation of an automated mosquito surveillance system which classifies Aedes and Culex mosquitoes by genus and sex. Parasites Vectors 17, 97 (2024). https://doi.org/10.1186/s13071-024-06177-w

Ongoing Field Tests Under E4Warning

The E4Warning project is testing the efficacy of the IRIDEON smart-traps under various conditions:

• Spain (Barcelona): VECTRACK sensors are deployed at five strategic monitoring sites across the city, focusing on Culex pipiens and Aedes albopictus. Agència de Salut Pública de Barcelona – ASPB
• Brazil (Rio de Janeiro and Brasilia): Field trials with local populations of Aedes aegypti and Culex quinquefasciatus in collaboration with Instituto Oswaldo Cruz, Fiocruz. Fundação Oswaldo Cruz (Fiocruz)
• Spain (Girona): Testing in non-urban environments like the Botanical Garden of Blanes and Aiguamolls de l’Empordà Natural Park, where diverse mosquito species are present. CSIC
• Greece (Athens): Planned deployment in the Attica region, focusing on critical points of entry for Aedes aegypti and areas of significant vector importance. Benaki Phytopathological Institute

To learn more about IRIDEON smart-traps refer to:

• González-Pérez, M.I., Faulhaber, B., Aranda, C. et al. Field evaluation of an automated mosquito surveillance system which classifies Aedes and Culex mosquitoes by genus and sex. Parasites Vectors 17, 97 (2024). https://doi.org/10.1186/s13071-024-06177-w
• González-Pérez MI, Faulhaber B, Williams M, Brosa J, Aranda C, Pujol N, et al. A novel optical sensor system for the automatic classification of mosquitoes by genus and sex with high levels of accuracy. Parasit Vectors. 2022;15:190. https://doi.org/10.1186/s13071-022-05324-5.

During the E4Warning project, we are employing various methods to collect blood-engorged female mosquitoes to study their feeding patterns. The techniques include carbon-dioxide-baited BG-traps, mechanical aspiration with a powered vacuum aspirator, and artificial resting sites. Sampling began in April 2024 and will continue monthly until November 2024 for this year.

From June 10-15, we hosted Dr. Nathan Burkett-Cadena and Tanise Steen from the Florida Medical Entomology Laboratory, University of Florida, at our study area in Aiguamolls de l’Empordà (Girona, Spain). Their visit aimed to test these collection techniques and share their expertise. They brought vacuum aspirators and resting traps developed by their lab to evaluate their combined efficacy in capturing blood-fed female mosquitoes across different habitats.

The Florida researchers developed human-powered resting traps designed for cavity-resting mosquitoes like Culex. These traps, set among vegetation in dark areas, attract mosquitoes seeking refuge during the day. Traps are placed horizontally to attract Culex and vertically to attract Anopheles mosquitoes and are collected the following day.

To maximize mosquito collection, we combined resting shelter traps and BG-traps with a large-diameter aspirator. These aspirators, designed by Dr. Burkett-Cadena’s team, use an automotive radiator fan to create directional airflow, capturing mosquitoes in a mesh-bottom plastic collection cup.

The insights gained during this visit and throughout the 2024 mosquito season will help finalize protocols for capturing blood-fed females, aiding in our study of mosquito feeding patterns.

• Burkett-Cadena. 2011. A wire-frame shelter for collecting resting mosquitoes. Journal of the American Mosquito Control Association 27: 153–155
• Burkett-Cadena et al. 2019. Human-powered pop-up resting shelter for sampling cavity-resting mosquitoes. Acta Tropica 190: 288-292
• Sloyer et al. 2022. Evaluating sampling strategies for enzootic Venezuelan equine encephalitis virus vectors in Florida and Panama. PLoS Negl Trop Dis.16:e0010329
•  Jaworski et al. 2022. Artificial resting sites: An alternative sampling method for adult mosquitoes. Medical and Veterinary Entomology 36: 139–148

The XI International Conference of the EMCA, held from November 7th to 10th, 2023, in Palma de Mallorca, served as a gathering for vector control specialists to share research and insights. With the theme “Shaping the Future of Vector Control in Europe,” the conference was organized by Dr. Francis Schaffner, president of EMCA, along with Dr. Carlos Barceló and Prof. Miguel A. Miranda from the Universitat de les Illes Balears (UIB). Among the highlights was E4Warning’s presentation on their Mark-Release-Recapture (MRR) experiments with Culex pipiens mosquitoes.

Eva Veronesi from SUPSI discussed the developed protocol for breeding, marking, and recapturing these mosquitoes and shared preliminary results from two pilot studies conducted in Switzerland last September. These studies are vital for understanding mosquito behavior and movement, key factors in vector-borne disease control.

The MRR technique, a fundamental method in ecological studies, involves capturing, marking, and releasing individuals back into their environment, then recapturing them after a period. This technique provides insights into movement patterns, survival rates, and population sizes, crucial for ecological and epidemiological studies.

In the summer of 2024, these methodologies will be applied in Switzerland and Spain to study the dispersal capacity of Culex mosquitoes, especially Culex pipiens and Culex molestus, which are known for transmitting the West Nile Virus (WNV).

These experiments are part of Work Package 5 (WP5) in the E4Warning project, which focuses on quantifying and understanding the movements of both vectors (mosquitoes) and hosts (birds) in WNV transmission. The data obtained will be instrumental in developing strategies to control WNV in Europe.

Additionally, the conference served as a valuable meeting point for various partners involved in the E4Warning project. This opportunity for face-to-face interaction and collaboration among researchers and specialists was crucial for fostering synergy and advancing the project’s objectives. Such gatherings reinforce the importance of collaborative efforts in addressing public health challenges like vector-borne diseases.