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

In November, Kamran Safi from the Max Planck Institute of Animal Behavior visited the CEAB-CSIC team leaded by Frederic Bartumeus and the Girona study area: the Aiguamolls de l’Empordà Natural Park. This visit was instrumental in familiarizing with the study area and engaging with local stakeholders: the park staff, regional mosquito control officials, and local ornithologists.

The meeting facilitated the selection of five common and abundant bird species present across various study zones for tracking their mobility patterns using GPS or Sigfox biologging. While bird migration and mobility have been studied on large scales, there’s limited data on the daily mobility of resident species and the impact of the landscape on their movements. Understanding these aspects is vital to determine the role different species play in transmitting pathogens like the West Nile virus across areas, such as from marshes or rice fields to peri-urban or urban zones.

Wild birds, being primary hosts of the virus, play a crucial role in its spread, thereby shaping the epidemiology of the disease. Assessing how they connect habitats and transfer pathogens is particularly crucial in human-altered landscapes where pathogen spillover between birds and humans can be facilitated. The lack of detailed information in the dissemination process of zoonotic pathogens undermines risk assessments and management plans. A key goal of WP5 is to quantify the mobility of various host species to develop a spatially-explicit approach to wildlife epidemiology.

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.