Certain species of ticks and mosquitoes can carry various diseases.
In Wisconsin, Lyme disease is becoming more common with nearly 6,500 cases reported last year, with many cases reported in the Northwoods.
The state sees spikes of illnesses from Powassan and West Nile Viruses every couple of years.
Dr. Erin Mordecai is a professor of biology at Stanford University and a senior fellow at the Woods Institute for the Environment.
She says we’ll likely see more cases of those diseases, as well as diseases typically seen more to our south, as the climate changes and we see more days that those insects are active.
“A mosquito or a tick, is a cold-blooded organism. It's body processes, how quickly it digests its food, and how long it lives, and how long it takes to develop, all of those things depend on the temperature of the environment around it,” said Moredcai. “As it gets warmer, those developmental processes happen faster, so you get more mosquitoes, more ticks, they're more likely to survive the incubation period of the pathogen.”
While climate change may be providing better conditions for tick and mosquitoes to thrive in, human activity plays a large role in transferring ticks either just through travel or by fragmenting forested habitats.
“There's a lot of complex factors. It's not just the warming of the temperature either. It's also changes in precipitation cycles and humidity that are important for these mosquitoes and ticks,” said Mordecai.
Controlling tick and mosquito populations also becomes more complicated.
As mosquitoes and ticks are active earlier and later, it might require more frequent or changing control methods.
Dr. Lyric Bartholomay with University of Wisconsin-Madison is co-director of the Midwest Center of Excellence for Vector-Borne Disease.
“A community may have a situation where they have excellent mosquito control, but it only is scheduled for May to August, and so we may need to really think about how we can shift that to cover the mosquito season and the fact that these things are staying out longer,” said Bartholomay.
She says this has also made it harder to do research on things like mosquitoes. Normally she has students working with her during their summer breaks, but mosquitoes are now remaining active as they return to school.
“We really now need to have more people on board in order to be able to do all the work to trap and identify mosquitoes and test for viruses,” said Bartholomay.
A climate central analysis found that the north central region of Wisconsin has about 15 more days per year that are suitable for mosquitoes than it did 40 years ago.
Bartholomay and Mordecai spoke as part of a SciLine panel on the impact of climate change on ticks and mosquitoes.
