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There Are More Fireflies In Chicago Than Usual This Year. Here's Why


This summer, Chicagoans are noticing more lightning bugs, as they call them. We've seen other upticks like this elsewhere, such as in Texas in 2016. And to find out if this is part of something bigger and brighter, we turn now to Doug Taron. He's chief curator at the Chicago Academy of Sciences and its Peggy Notebaert Nature Museum. And we're catching up with him in the field. Literally, he's doing fieldwork near the town of Braidwood in north-central Illinois. Good morning.

DOUG TARON: Oh, good morning. Thank you.

GARCIA-NAVARRO: I must start by asking you - fireflies or lightning bugs?

TARON: I use fireflies. I grew up in New England. That's what we called them there.

GARCIA-NAVARRO: OK. I know that this is a huge divide. They are nocturnal. So are you observing them sleep, or are you studying something else out there right now?

TARON: We're actually doing the butterfly survey out here. The fireflies I've been seeing in Elgin, Ill., which is a northwest suburb of Chicago.

GARCIA-NAVARRO: All right. So these lightning bugs - what's your best idea about why you're seeing more of them this year?

TARON: Here in the upper Midwest, we have had a very, very wet spring. And larval fireflies eat things like worms and little snails and roly polies. And all of those animals do very, very well in wet soil. So it's given the larval fireflies a really good food supply this year.

GARCIA-NAVARRO: When we think about development and pesticides and climate change, that has been a reason some have suggested we might have seen a thinner lightning bug populations in other years. Do you think that's the case?

TARON: Well, I certainly think that those things could be contributing factors. A lot of the fireflies that people are seeing in the Chicago area right now are a very common species of fireflies that can be found in suburban areas. They and the things that they eat are potentially going to be negatively affected by things like pesticide use on lawns.

GARCIA-NAVARRO: Other than being synonymous with summer, what's the main benefit of having a healthy, well-balanced population of lightning bugs?

TARON: Well, fireflies are just part of good biodiversity that you're going to see in a healthy ecosystem. Because of their luminescent habits, they're often much more noticeable than other smaller and less conspicuous members of the insect community. But because of that, they're good indicators of what might be going on with other species.

GARCIA-NAVARRO: So they literally light the way. What do you think at the moment? Do you think that this population is under peril, or is this just part of a natural cycle?

TARON: Well, fireflies are actually a large number of different species. Some species of fireflies, particularly those that have very specialized habitats, are, in fact, in trouble and becoming imperiled. The one that people are seeing in the Chicago area right now is still a relatively common species. And so it's a little harder to tell without one whether this is part of a longer trend or if this is just a single good year that they're having.

GARCIA-NAVARRO: What can we do as citizens who love fireflies to help them thrive?

TARON: Well, the species of fireflies that live in people's yards that we tend to see more and be more up close to don't like a really, really tidy landscaping. So they're going to like it if you don't mow your lawn every week, if you're not having your lawn looking like a putting green. Also, in the fall, if you're not raking up all of the leaves - all of those things are going to be good for fireflies.

GARCIA-NAVARRO: Doug Taron of the Chicago Academy of Sciences, good luck in your fieldwork. And thank you very much.

TARON: Thank you for having me. Transcript provided by NPR, Copyright NPR.