Snapshot Wetland Mosquito Survey
The Snapshot project aims to expand mosquito surveillance in wetland habitats, and to further collaboration and public engagement in arbovirus surveillance across England.
Mosquito snapshot survey
The Snapshot survey aims to provide a stratified approach to wetland mosquito sampling across England, provide data on native mosquito distributions and arbovirus (arthropod-borne virus) presence, and develop collaboration and public engagement to support vector surveillance.
The project provides samples for West Nile virus and Usutu virus testing and all data generated is used by the UK Health Security Agency (UKHSA) Medical Entomology team (MEZE) to inform One Health cross government risk assessments on mosquito-borne disease (HAIRs).
The project aims to sample at least one wetland site in every 50km grid square in England every summer between the months of July to September, inclusive, to enable an expanded survey of native mosquitoes and potential arbovirus transmission in wetland habitats.
This is a volunteer-supported project in collaboration with the Real-time Arbovirus Detection And Response (RADAR) project. Mosquito traps are run by volunteers from numerous organisations who have access to wetland habitats, notably the Royal Society for the Protection of Birds (RSPB), British Trust for Ornithology (BTO), Wildfowl Wetlands Trust (WWT), the Wildlife Trust, local authorities, and members of the public.
Figure 1: Map of England divided into 50km grid squares, showing Snapshot Mosquito Survey site from 2024
We hope all data collected will help optimise future surveillance strategies to support improved assessments of arbovirus risk across a wider geographic area and help target key vector groups to protect wildlife and public health in the future.
We aim to make the Snapshot Wetland Mosquito Survey a core component of UKHSA mosquito surveillance and a component of the National Contingency Plan for West Nile Virus in England in 2026.
Mosquito sampling methods
The project aims to sample a wetland site in every major 50 km2 grid square in England during the season of peak vector activity (July to September).
Wetlands are targeted for sampling as these habitats support a variety of mosquito species and are also sites where migrating birds are likely to make landfall and remain for extended periods.
Traps are deployed for three-night trapping sessions, and sessions are repeated 2 to 3 times, with exact trapping dates determined locally to allow for volunteer flexibility.
All mosquitoes captured are posted back to our laboratory on the last trapping day of each trapping session.
Mosquitoes are identified to species-level using taxonomic keys.
All mosquito samples collected are identified on dry ice to keep virus integrity and screened for Usutu and West Nile viruses.
The BG Pro Mosquito Trap
Mosquitoes are attracted to hosts (for example mammals, including humans, and birds) using carbon dioxide and skin scent cues, with host preference varying by species. The BG Pro mosquito trap is designed to mimic these cues using a BG Mozzibait attractant - an artificial scent designed to replicate host scent cues. Bird and mammal-biting mosquitoes in the area are attracted towards the lure, which is placed inside the trap. A small fan then draws these mosquitoes in and prevents them from escape. The mosquitoes are trapped inside a drawstring catch bag, that can then be removed and posted to us for analysis.
We can improve mosquito capture using a carbon dioxide source alongside the BG Mozzibait. This comes in the form of a bag of yeast, sugar and water that will produce carbon dioxide for approximately 24 hours.
For trap use, please refer to the short videos on the RADAR website
Figure 2: The BG Pro in a wetland habitat
This is a small, portable and easy to assemble mosquito trap.
Get involved
This project focusses on wetlands, nature reserves, and other sites likely to be harbouring native mosquitoes and migratory birds. Trapping should be conducted with local permissions. Sites should be relatively free of vandalism, and easy to access by volunteers.
We ask volunteers to please position the trap in an area sheltered from high winds and heavy rain, and to avoid placement accessible to livestock or easily visible to members of the public.
The trap will be most effective when standing near shady areas, such as bushes, shrubs and hedges. They are ideally positioned near small or shallow water bodies that may be mosquito breeding sites. Wherever you may have noticed mosquitoes or where you have been bitten in the past, is probably a good place.
Aims:
- together sample at a wetland site in every 50km grid square in England
- target areas of mosquito activity and migratory bird landfall
- conduct 2 to 3 trapping sessions between July to September, inclusive
- ideally conduct one session per month
- run the trap for 3 consecutive nights per session
- post mosquito catches back on the last day of each trapping session
- provide photos of trapping locations to gather microclimate data
For more information about the Snapshot survey, see the mosquito map on the RADAR website.
Contact us:
If you’re interested in running a trap for the project, please contact us at: wetlandmosquito@ukhsa.gov.uk, and put ‘Snapshot Wetland Mosquito Survey 2026’ in the subject line.
Main resources for snapshot survey:
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