Researchers report that the Asian tiger mosquito,Aedes albopictus,has become more abundant across Illinois in the past three decades.

The data was compiled from a variety of sources, the researchers said.

This mosquito's spread is problematic, as it can transmit diseases – like chikungunya or dengue fever – to humans.

The Asian tiger mosquito originated in the forests of southeast Asia. It found its way to Texas around 1985 and very quickly spread to Illinois.

"The global trade in used tires facilitates the spread of the mosquito," Chris Stone, a medical entomologist at the Illinois Natural History Survey and the lead author of the new study, said in a news release from the University of Illinois.

“The eggs get stuck to the walls of the tires and can survive even in dry conditions. Tires are also great at retaining rainwater, which is perfect for the larvae to develop in.”

Stone and his colleagues wanted to understand how the mosquitoes were able to spread across Illinois, given how cold the state’s winters can be.

"We looked at historical records to see where the mosquito has been observed in the state. We then compared that information to the winter temperatures in different counties," Rebecca Smith, a professor of pathobiologyat the University of Illinois at Urbana-Champaign who led the research with Stone, said in the release.

“Winters are fairly warm in cities like Chicago because of all the roads and concrete. There are a lot of places like sewers and subways where these mosquitoes can live in the winter.”

The spread of the Asian tiger mosquito in Illinois also is a result of repeated introductions from neighboring counties.

The researchers also used genetic information to track the spread of the mosquitoes, focusing on mitochondrial DNA, which is abundant in cells. Comparing mitochondrial DNA sequences is an established method for studying the spread of mosquitoes globally.

Asian tiger mosquitoes are good at outcompeting other mosquitoes, the researchers said. This can have both beneficial and harmful effects.

“The ability of the Asian tiger mosquito to establish itself in Illinois could be problematic from a public health perspective,” Smith said in the release “Although it is not as bad as the yellow fever mosquito, it has the potential to introduce diseases.”

The researchers report their findings in the Journal of Medical Entomology.

The INHS is a division of the Prairie Research Instituteat the U. of I.