Abstract
Invasive mosquitoes continue to spread, increasing the threat of mosquito-borne disease. Ongoing mosquito surveillance is necessary to track the introduction and establishment of these species in new areas and implement appropriate public health and vector control measures. Contributions from citizen science initiatives have been an important component in detecting, controlling, and raising awareness of invasive mosquitoes. The open-access biodiversity platform iNaturalist is an extensive source of human observations of wildlife, including arthropod vectors, and can be a useful supplementary tool for passive vector surveillance. In this study, the utility of iNaturalist data to support invasive mosquito surveillance was assessed by examining the distribution and seasonal data on four invasive Aedes species (IAS) in Europe and neighbouring countries. Almost 16,000 iNaturalist observations of mosquitoes were examined across 62 countries; 13% were identified as IAS, with a further 2% considered probable IAS. These included 16 observations of Aedes aegypti, 1582 Aedes albopictus, 373 Aedes japonicus, and 58 Aedes koreicus. iNaturalist observations of IAS were present in most known areas of establishment, but potential new regions of spread were also identified. These results further support the use of iNaturalist data as a low-cost source of arthropod data to assist existing vector surveillance.