Looking for lightning bugs? Shining a light on fireflies

On June 19 my friend

Pam posted a distressed message on Facebook. “Something feels very wrong,” she said. “Not a single lighting bug … so far.” The post made me realize that while I’d noticed a few fireflies in our yard during the previous week or so, I hadn’t seen the dozens or even hundreds that I usually do.

Pam wasn’t the only one who’d been observing the lack of fireflies. The following day I received an email from “From the Ground Up” reader Ray Zielenski. “While I was out walking my dog tonight,” he wrote, “I think I only counted 3 fireflies twinkling their mating lights during the entire 40 minutes Molly and I were out. I began to wonder ‘Why is this?’”

He continued, “I remember from my childhood that during the summer there were hundreds, perhaps thousands of them easily visible each night as the sun went down. I began to hypothesize that maybe all the … pesticides people put down on their lawns might be killing them.”

Ray offered further thoughts and findings. “Some online research suggests that the dry spells we’ve had of late might be a cause, as firefly larvae love the wet muddy soils of spring and the warm humid air of summer. That combination supplies food for their appetites: grubs, aphids, and tiny snails.”

From Ray’s notes plus a bit of internet searching of my own, I think that Ray’s hypothesis is probably correct. May and most of June were exceptionally dry this year and that could have been enough to throw off the life cycle of an insect that needs moisture. But I came across more information that would indicate that although we can probably chalk up this year’s firefly deficit to lack of rainfall, there are other, ongoing factors that are contributing to a problem for firefly populations in general. So far, pesticides don’t seem to be a contributor.

Habitat degradation — encroachment on and draining of marshy areas — is reducing habitat. And whether our long dry spell can be attributed to climate change per se or not, lack of moisture in the ground has a serious impact.

If you love fireflies and can’t imagine summers without them, here are some tips from www. americannativeplants.com:

— Plant native pine trees. (e.g., white pine, Pinus strobus.) According to the website, “Lighting bugs mate and lay their eggs in the canopy of native pine trees. The trees provide a dark, safe place for fireflies to rest during the daytime.”

— Let some of the grass in your yard grow taller. “Fireflies are attracted to high grasses and shrubbery, and they rest on tall blades of grass during the day. Mowing too often can reduce the number of fireflies in your yard in general.”

— Install a water feature. “Fireflies love moisture, especially standing water areas like marshes and ponds. The insects live and mate near the water.”

— Turn off outside lights. “Outdoor lights can interfere with a firefly’s glow, which is used to ward off predators and attract mates. By turning off landscape and deck lighting, you’re providing fireflies with a dark, safe place to thrive.”

About a week ago my friend Pam posted an update. I could hear the relief in her words. “Finally! I saw fireflies tonight.” But still, the numbers weren’t great. Just a few fireflies sparking up out of the grass. I continue to see the same on my property.

Note: For more about the risks to fireflies of habitat degradation and climate change, go to https://tinyurl.com/a6d568pd

Fun Fact: The firefly, Photuris pennsylvanica, is Pennsylvania’s state insect. For that, we can thank elementary school students in Upper Darby who noticed that while Maryland had a state insect, PA did not. The students made a proposal to the PA General Assembly and the firefly was formally adopted as our state insect on April 10, 1974.

Pam Baxter is an avid organic vegetable gardener who lives in Kimberton. Direct e-mail to pamelacbaxter@gmail.com, or send mail to P.O. Box 80, Kimberton, PA 19442. Share your gardening stories on Facebook at “Chester County Roots.” Pam’s nature-related books for children and families are available on Amazon, at Amazon.com/author/ pamelabaxter.