Europe has a new mosquito problem, but it may not be the one you think

Europe’s cold-tolerant Korean bush mosquito can thrive where other invasive mosquitoes struggle, raising new questions about how it should be tracked, identified, and assessed for disease risk.

Study: Just another white-striped mosquito? A scoping review and group discussion synthesis on Aedes koreicus in Europe. Image Credit: Cloudpost / Shutterstock

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Background

Researchers searched Web of Science and Scopus on June 6, 2025, using “Aedes koreicus” OR “Ae. koreicus.” The search was updated on February 17, 2026. Two authors screened titles and abstracts, resolving disagreements by discussion. Eligible papers had to be published in peer-reviewed journals and investigate Aedes koreicus; preprints and conference abstracts were excluded. Distribution records were combined with European Centre for Disease Prevention and Control VectorNet data and Mosquito Alert citizen-science records.

A multidisciplinary workshop was held in Trento, Italy, on February 10, 2026, with 41 participants from six countries, all of whom were based within the species’ non-native range. Participants worked in five discussion groups, and rapporteurs recorded key arguments and recommendations. Participants represented ecological and epidemiological modeling, medical and field entomology, and public health practice, providing cross-disciplinary perspectives on operational challenges and research priorities for the species.

Evidence base and European spread

The search identified 334 articles. After 222 duplicates and 21 ineligible studies were removed, 91 articles remained, all published after 2011. Most studies were conducted in Europe, with 55 focused on surveillance. Aedes koreicus is native to China, Korea, and eastern Russia. Its first documented detection outside its native range occurred in Belgium in 2008. The review subsequently recorded detections in Italy in 2011; Russia and Slovenia in 2013; Switzerland in 2013; Germany in 2015; Hungary in 2016; Austria and Kazakhstan in 2018; the Czech Republic in 2021; and Slovakia in 2024.

Surveillance and identification

A major practical problem is distinguishing Aedes koreicus from morphologically similar mosquitoes. Standard ovitrap monitoring cannot reliably distinguish its eggs from those of Aedes japonicus, Aedes albopictus, or Aedes geniculatus. Because Aedes koreicus is more cold-tolerant than Aedes albopictus, it may be active earlier in spring and later in autumn.

In one blinded validation study, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) correctly classified all tested Aedes koreicus eggs, although reference spectra and specimen quality can affect identification. Optical recognition of egg patterns can distinguish some species, but Aedes japonicus and Aedes koreicus remain difficult to separate. Wing-shape analysis achieved reclassification accuracies of 96.5% for females and 91.3% for males.

Environmental DNA (eDNA), combined with real-time polymerase chain reaction and loop-mediated isothermal amplification, is promising but requires further validation. Citizen science can expand coverage, although uneven participation and difficulties with photographic identification limit its use for rigorous inference.

Genetics and biology

Genetic studies using mitochondrial cytochrome oxidase I (COI) and NADH dehydrogenase subunit 4 (ND4) markers identified at least five major haplotype groups, suggesting multiple introductions from Asia followed by dispersal and admixture. Analysis of 145 COI samples identified a highly divergent haplotype from Austria and Belgium, raising the possibility of distinct genetic lineages or cryptic species. Genome studies identified features potentially associated with cold tolerance and environmental adaptation, but their functional significance remains unclear.

Temperature strongly influences performance. The optimal range is generally 20-28°C; temperatures above 30°C negatively affect survival and fecundity, while temperatures below 10°C are largely unfavorable for development and activity. Diapause improves egg survival and hatching after subzero exposure. Laboratory evidence indicates weak larval competition with Aedes albopictus, while natural interactions remain uncharacterized. In the only quantitative European blood-meal study identified by the review, European roe deer accounted for about 63% of blood meals and humans for about 15%, although feeding patterns appeared to be strongly influenced by local host availability.

Vector competence, control, and modeling

Experimental laboratory studies show that Aedes koreicus can become infected with Dirofilaria immitis and arboviruses, including Sindbis, dengue, chikungunya, and Zika viruses, and may support transmission under specific conditions. Transmission is generally low for chikungunya and Zika but increases under warmer conditions. Dengue transmission was observed at 28°C in one study and at 26°C with 20% efficiency in another, while Sindbis virus showed 67–100% transmission efficiency in a limited sample. The species failed to transmit West Nile and Tahyna viruses under laboratory conditions. The authors considered it unlikely to be a primary arbovirus vector, although high local abundance and suitable conditions could allow localized contribution to transmission.

Few studies assessed insecticide resistance. Findings varied by insecticide and sampling period, while an Italian study confirmed larval susceptibility to Bacillus thuringiensis at a lower rate than in Aedes albopictus. Modeling studies included correlative and mechanistic approaches, but limited and inconsistent biological and surveillance data restricted model development, calibration, and validation.

Communication and priorities

Experts emphasized transparent communication without alarmist messaging, as the public health relevance remains uncertain. They favored integrated mosquito management and engagement of schools, citizen scientists, and local stakeholders. Priorities included broader surveillance in montane and lowland areas, improved species identification, research on vector competence and competition, harmonized long-term datasets, and stronger genomic and ecological research.

Conclusions

The authors concluded that Aedes koreicus remains understudied despite nearly two decades of detection in Europe. The review established a baseline, while acknowledging that records may be missing from bibliographic databases and that earlier taxonomic confusion can limit completeness. They identified revision of surveillance frameworks, reliable species identification, and harmonized long-term surveillance datasets as priorities. They also considered genomic, ecological, vector-competence, and competition studies necessary to resolve knowledge gaps. They emphasized that the species should currently be communicated primarily as a nuisance rather than an established human public health threat, while uncertainty and veterinary concerns require continued attention from stakeholders.

Journal reference:

• Marini, G., Mancini, M. V., Damiani, C., Kurucz, K., Albieri, A., Arnoldi, D., Bahrami, R., Battistin, G., Blaha, M., Bonetto, D., Danca, L. I., Di Castri, S., Di Santo, C., Erguler, K., Ferrari, N., Flacio, E., Franceschini, A., Gingell, D., Gobbo, F., Gradoni, F., Grisendi, A., Khorramnejad, A., Longo, E., Manica, M., Marinozzi, M., Marsboom, C., Melillo, S., Montarsi, F., Nuryady, M. M., Paoli, F., Rosà, R., Rota-Stabelli, O., Scremin, M., Situmorang, T., Sogliani, D., Spaccapelo, R., Van Bortel, W., Veronesi, R., Visentin, P., Lencioni, V., & Da Re, D. (2026). Just another white-striped mosquito? A scoping review and group discussion synthesis on Aedes koreicus in Europe. Acta Tropica. DOI: 10.1016/j.actatropica.2026.108302, https://www.sciencedirect.com/science/article/pii/S0001706X26003359