Fireflies/Lightning Bugs In Illinois: Why We’re Seeing Less

We're at the mid-point of June in 2025 and I have yet to see more than two lightning bugs (or, fireflies if you prefer) in my backyard flashing their tail-lights at the same time. Usually, it's only one of them.

This is a big difference from when I was a kid, and it's even a big difference from what I remember seeing 20-plus years ago when my kids were small and heading outside to fill a jar with them.

For those of a certain age, you probably remember seeing lightning bug populations that looked more like this than what we see today:

Before We Get Into Why We're Not Seeing As Many Of These Little Bugs As We Did Years Ago, I Have To Ask: What Do You Call Them?

Growing up, we called them lightning bugs, and only lightning bugs.

As to whether most people call them fireflies or lightning bugs, a poll at YouGov determined that 60% of people living in the western United States prefer the term firefly over the 25% that say lightning bug.

In our part of the country, it's different:

Those living in the Midwest are the most likely to refer to these flickering fliers as “lighting bugs.” Nearly three in five Midwesterners (59%) call them this, while one-third (33%) say they are fireflies. Midwesterners that live on the Western side of the region (37%) are slightly more likely than those on the Eastern side of the region (30%) to refer to them as fireflies, though majorities in both parts of the region tend to say lightning bugs (55% and 62% respectively).

Whatever You Prefer Calling Them, The Population Of Fireflies/Lightning Bugs Is Shrinking Nearly Everywhere In The Country

I say nearly everywhere in the country because there's one state that doesn't have fireflies/lightning bugs, and that's Hawaii. The other 49 states all have lightning bugs/fireflies, and they're not all the same.

USAToday:

In North America, there are more than 170 species of Lampyridae, or light-emitting beetles, and there are more than 2,000 types worldwide. And they've been around for millions of years.

In Illinois, experts think that we have between 27 to 32 different species of lightning bugs/fireflies, but most of the ones we have here in Illinois look like this:

So, Why Are There Less Fireflies/Lightning Bugs Now, And How Serious Is This?

One of the problems with figuring this out is the fact that despite these glowing bugs being a big part of summer outdoor nightlife, there just haven't been very many studies of them, which is something researchers across the country are trying to change.

Based upon what is known about these insects currently, the reasons most researchers think that we're seeing less of them is three-fold: Habitat loss to development, light pollution, and use of pesticides.

So, how can you protect the lightning bugs we have? Horticulture educators Ken Johnson and Jamie Viebach with the U of I have these suggestions, according to NBCChicago.com:

• "Dim or turn off unnecessary outdoor lights at night," Viebach said. "For required lighting, use dark sky friendly outdoor fixtures. These fixtures are typically shaded to direct light downward, where it’s needed, instead of laterally and up. Even closing the shades inside can help reduce the amount of light escaping to the outside."
• "Provide habitat for fireflies," Johnson said, urging Illinoisans to let parts of their landscaping "go wild" and to mow less frequently. Not picking up leaves in the fall can also help.
• Avoid using insecticides or pesticides, including things like mosquito foggers. Instead, use "non-chemical methods, like fans and removing standing water to prevent mosquito issues," Viebach said.