CHAMPAIGN, Ill., 8/26/22: The exotic Asian tiger mosquito, known to transmit diseases to humans, is more widespread in southeastern Illinois than previously realized, according to Illinois Natural History Survey (INHS) researchers who conducted a study on how invasive mosquito communities form and shift because of different land uses.
Findings from the study of mosquito communities will aid in understanding the potential risk posed by invasive species and their expansion in Illinois within the broader goal of predicting and preventing emerging vector-borne diseases in the state, said Valeria Trivellone, INHS postdoctoral researcher.
Asian tiger mosquitoes, Ades albopictus, are a health concern because they can be vectors of viral pathogens such as the La Crosse virus and may be able to transmit West Nile, Zika, chikungunya, and dengue viruses in the United States. In the two-year study in 2016 and 2017, researchers conducted a surveillance survey of mosquitoes in 18 communities from 17 southeastern Illinois counties representing rural, semi-rural, and urban landscapes.
They found the Asian tiger mosquito in all 18 communities and learned it has become established in nine counties where it had previously not been found, indicating that the species has spread and has become well established in southern and central Illinois.
The study also looked at the link between different mosquito species and habitats, such as cities, where the Asian tiger mosquito most often dwells, and agricultural areas and wetlands. Although mosquitoes have a preference, some species can adapt more than others to changing climates and human-driven environmental changes and spread into new areas. The concern with the tiger mosquito species is that it is invasive and can out-compete indigenous species that are less well known as disease vectors. The Asian tiger mosquito, for example, is more prevalent in locations where species diversity is fairly low.
“In Illinois, the species adapted to the current landscape situation, which may be a red flag because all the elements exist for an emerging disease at any moment,” Trivellone said.
Besides mosquitos’ adaptability, diseases may also emerge when a pathogen invades new areas or new habitat types. Also, there is a risk when mosquito species acquire a virus that they’ve never encountered before, as a result of expanding their geographic range, and transmit a virus to a new susceptible host, whether humans or animals.
Studying entire mosquito communities and monitoring the presence of different viruses in Illinois is important to understand the interplay between potential vectors and pathogens in different habitats.
“An important point to understand is that basically viruses don’t care about the species’ names,” Trivellone said. “If two different species are suitable disease vectors, they are the same from the virus’s point of view. We need to study mosquito communities to gain insight on how invasive mosquito species affect disease patterns and how they fit within or change the broader community in new locations where they’ve invaded.”
The researchers found that communities in various locations were quite different from each other. Information about how human-modified environmental factors influence mosquito communities and the prevalence of disease vectors and how invasive species fit into existing groups in areas outside of their normal range can help predict the emergence and spread of diseases.
Trivellone is part of the INHS Medical Entomology Program, a group of scientists who collaborate with the Illinois Department of Public Health to conduct statewide mosquito monitoring, surveillance, and basic research on vector competence. The research team is taking proactive steps to provide, translate, and integrate scientific data to develop protocols for policymakers involved in public health.
The study was published in the journal Frontiers in Public Health.
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Media contact: Valeria Trivellone, valeria3@illinois.edu
news@prairie.illinois.edu