MOLINE, Ill. — Record-breaking cold in 2019 and a brutal month of February this year makes us wonder if this will affect the bugs we see here in the spring and summer by reducing their population sizes. Let's verify.
THE QUESTION
Do harsh winters impact bug or insect populations?
THE ANSWER
After an extremely cold winter, some bugs may see lower numbers at first but are able to rebound population size by the summer months. No, harsh winters will not impact population size.
WHAT WE FOUND
Our source is Dr. Ryan Smith who is an Assistant Professor in the Department of Entomology at Iowa State University. "Ultimately a really harsh winter might maybe kind of suppress, you know whether it may be tick or mosquito populations, uhh initially kind of during the spring but for the most part it really doesn't make that much of a difference," says Smith.
The bugs and insects native to our hometowns know the weather and have adapted. They also have mechanisms that have allowed them to fight these harsh winters. Snow even acts as an insulator to keep some of these bugs warm! If they live here and have established a population, they will continue to thrive. “I think a general rule of thumb is that if they’re able to survive and live here in any real significant numbers, they’ve found ways to get around it and have found ways to survive the winter," says Smith.
Weather is still an important role in bug population size, but that comes from factors during the spring months. How warm we are during the spring and the amount of rainfall are very impactful to how soon we see bugs in substantial numbers. Mosquitoes for instance love water and after a rainfall event, we often see notable hatchings of these insects.
Not only have we experienced some colder winters, but we have also experienced summers stretching longer into the fall. This allows the threat for new species to creep in. Species that scientists didn't expect to be able to establish populations here due to our winters. Some examples of these foreign bugs would be the Jumping Worm, Emerald Ashe Borers, and different types of mosquitoes. This can cause public health and environmental problems as some of the bugs carry diseases.
“For instance, this one mosquito species, Aedes albopictus, which was we found kind of more recently, definitely took a hit in 2019," explains Smith. After the record-breaking cold, this mosquito species slightly reduced in population size. They were able to rebound with our warmer summers. “They have really been able to kind of recover, I would say, and even if… that’s kind of the effects of the winter is if it doesn’t outright kill them it’s going to kind of slow them down," says Smith.