Here’s what you should know about climate variability and how it impacts mosquitoes, ticks

• Climate variability, characterized by fluctuating weather patterns, impacts vector insect populations like mosquitoes and ticks.
• While rain provides breeding habitats for mosquitoes, excessive rainfall can wash away nutrients and negatively affect tick populations by drowning them in saturated soil.
• Increased tick activity is observed after rain events as the soil dries and ticks seek food.

Climate change is causing changes in climate variability that is impacting the vector insect species.

Gonzalo Vazquez-Prokopec, professor in the department of environmental sciences at Emory University, said there’s a difference between climate change and climate variability.

“Climate change is more broad in scale,” said Prokopec. “It refers to long-term shifts in temperatures, rain and other weather patterns. You might have to talk about continental levels or even country levels. That’s different from climate variability. As many things happen in our atmosphere … we tend to see more variability.”

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In the Southeast, Prokopec pointed to the a year of heavy rain following a year of drought as instances of climate variability.

“That kind of variability in climate impacts mosquitoes and ticks,” he said.

A vector insect is an insect that can transmit diseases from one organism to another, according to the Centers for Disease Control and Prevention.  Vector insects can carry pathogens that can cause diseases in humans and other animals when they bite or feed on them. Examples of vector insects, according to the CDC, include:

Prokopec is an expert in vector species, which are bugs that transmit disease. He’s particularly interested in the linkages between those insects and the impact they might have on human health.

“There is an assumption that the more rain, the more mosquitoes,” said Prokopec. “That’s not true. Mosquitoes require rain. But they also require food bacteria. If it rains a lot you get a lot of habitats that fill in. But basically the nutrients get washed out.”

Prokopec added that studies with mosquitoes show how climate variability can impact an insect population.

“We did studies on mosquitoes that carry West Nile virus,” he said. “We found that what really matters for many of these insects is a sequence of those large events like rain followed by periods of no rain. Because of that variability it’s really hard to pinpoint what’s going to happen, what’s happening now and what will happen in a month or two months, regarding viruses that ticks and mosquitoes carry.”

Eco-friendly tips on how to manage vector insects and other pests, according to the US Environmental Protection Agency, include:

• Throw out containers that can hold water like buckets, tires, and flowerpots.
• Clean gutters and drainage systems making sure water flows freely and doesn’t stagnate.
• Maintain pools and fountains by cleaning them regularly and circulate water in these areas.
• Keep containers covered to prevent mosquito larvae from entering.
• Empty and scrub out containers like birdbaths, plant saucers, and buckets regularly.
• Citronella candles and torches can provide some repellent effects.
• Take a shower within two hours of coming indoors to remove any attached ticks or mosquitoes.

“A lot of rain creates a good environment for mosquitoes,” he said. “But a lot of rain can flood the ground and will negatively impact ticks. Actually, ticks basically drown in saturated soil. We’re looking at more rural areas. If you have a rain event, ticks are more likely to be hiding. But in about three or four days, once the soil has dried, they’re going to be hungry.”

Prokopec said following a rain event there will be an increase in tick activity.

“It’s not like an explosion of ticks,” said Prokopec. “Ticks depend on deer, mice and other animals. So, it’s really the whole ecosystem changing and in a way adapting.”

This reporting content is supported by a partnership with several funders and Journalism Funding Partners.

Erica Van Buren is the climate change reporter for The Augusta Chronicle, part of the USA TODAY Network. Connect with her at EVanBuren@gannett.com or on X: @EricaVanBuren32.