Invasive mosquito surveillance
Monitoring the presence of invasive mosquitoes which can present a risk to public health, and taking measures when the eggs of invasive mosquitoes are found.
Applies to England
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CCHS homepage
Topic: health impacts
Vector-borne disease: mosquitoes
Part of: monitoring and research
Important resources for invasive mosquitoes:
- Invasive mosquito surveillance
- Summary - information on invasive mosquitoes
- National continegancy plan for invasive mosquitoes
- Invasive mosquitoes species profiles
- Mosquito recording scheme (how to report)
More content:
Invasive mosquito surveillance
Aedes albopictus is a major public health concern because it is a known vector for diseases such as dengue, chikungunya, and Zika virus. Originally from Southeast Asia, it has spread globally due to climate change, trade, and travel.
Figure 1: Female Aedes albopictus
In Europe, it has contributed to local outbreaks of dengue in Spain, France, and Italy. Preventing its establishment in the UK requires coordinated surveillance, early detection, and rapid control measures, making seasonal monitoring essential for public health protection.
To address this threat, UKHSA Medical Entomology co-ordinates invasive mosquito surveillance, and works closely with local authorities and port health, to run mosquito traps at high-risk sites. These may include:
- airports
- ports
- service stations
- distribution centres
As well as other sites at a high risk of receiving cross-Channel traffic. UKHSA also provides guidance, training, and support to local authorities on conducting mosquito surveillance. Roles and responsibilities are outlined in the ‘National Contingency Plan for Invasive Mosquitoes’.
The UK’s invasive mosquito surveillance began in 2010, and the first Aedes albopictus eggs were detected in 2016 at a truck stop in Kent. Surveillance is primarily conducted by local health and port health authorities, focusing on high-risk locations such as ports, airports, service stations, and urban centres.
Figure 2: Locations of invasive mosquito detections since the first detection in 2016
The program uses ovitraps. These are water-filled traps designed to attract egg-laying female mosquitoes, particularly the Tiger mosquito. These traps are checked biweekly from June to October, a period when mosquito activity is highest. Collected samples are then sent to UKHSA for analysis.
Figure 3: Example of an ovitrap. This is used to detect Aedes albopictures females lookiing for somewhere to lay their eggs
Control actions when eggs are detected
If invasive mosquito eggs, such as those from Aedes albopictus or Aedes aegypti, are found, UKHSA entomologists and Environmental Health Officers (EHOs) would take immediate action to prevent their spread. Following the National Contingency Plan for Invasive Mosquitoes, an incident would be established by the Health Protection Team. An inspection of 300m radius around the site for potential breeding grounds, such as puddles, buckets, tyres, and other objects that can hold water. Any identified breeding sites would be removed, drained, or treated to prevent the eggs from hatching.
UKHSA Medical Entomology entomologists would deploy adult mosquito traps to monitor the area. If adult mosquitoes are detected, targeted treatments—such as source reduction, insecticides or biological controls—would be used to reduce their numbers. In locations where standing water cannot be eliminated, a special film would be applied to prevent egg hatching.
The local EHO team would collaborate with businesses and residents to raise awareness and provide guidance on eliminating standing water to reduce mosquito breeding risks. The area would be monitored for several weeks to ensure that the mosquitoes do not spread or establish a permanent population.
UKHSA offers specialised training events for local authorities. For more details, email mosquito@ukhsa.gov.uk with the subject line “Invasive Mosquito Training.”