A summer evening in North Carolina isn’t complete without fireflies, but are these insects truly harmless, or are they a pest? Our pest control company in Raleigh is exploring the science of these insects and whether you should welcome them to your yard or try to keep them at bay.

What Is a Firefly?

A firefly, also called a “lightning bug” in the South and Appalachia, isn’t a fly at all. It’s actually a type of beetle and part of the Lamypridae family, the name of which is derived from lampein which is the Greek word for “to shine.” While there are over 2,000 species of firefly not all of them light up, and many of them don’t even fly. However, the ones you most often see here in Raleigh are the Big Dipper firefly with their black bodies and wings with red and yellow markings.

Why Do Fireflies Light Up?

Fireflies produce light through bioluminescence, producing light through a biological process. In this case, as fireflies transport oxygen into the body through tracheoles, it reacts with luciferin, producing adenosine triphosphate and luciferase, which is a bioluminescent enzyme. Thus, light is produced.

Now that we know how they light up, let’s look at why they do. Not surprisingly, it’s generally a mating reaction. Male fireflies will emit their glow and fly upwards and downwards in a J pattern, and if a female sees this, she will briefly light up in a response that is timed to meet the male’s flashes. However, it’s not all about romance. Some females from the Photuris genus will mimic a Photinus female firefly’s pattern, attracting the male, which they will eat.

While it’s not related, fireflies’ light can turn away predators. Fireflies have a steroid called lucibufagins in their blood which tastes bad to predators. When a predator does eat them, they associate the bitter taste with their glow and avoid eating them.

Are Fireflies Harmless?

Fireflies typically begin emerging in North Carolina in early June, so if your yard becomes a lightning bug hotspot, feel free to welcome them as they are beneficial insects. They don’t bite or have anything that could be harmful to humans, they’re not poisonous unless eaten in very large quantities (which we certainly wouldn’t recommend), and they feed on other insects. Plus, the luciferin and luciferase chemicals that trigger their glow are often used in medical research for cancer, cystic fibrosis, and heart disease treatments.

If you don’t want these insects in your yard, maybe because you’re concerned a pet may try to eat them, they do avoid bright lights. Consider installing an LED porch light and keeping it on at night to move them toward other areas.

Call Stomp for Pest Control in the Triangle

While fireflies aren’t generally an issue, there are plenty of other pests in the region you don’t want to welcome into your yard or home, including wasps, mosquitoes, and ants. For those harmful and annoying pests, call us at (919) 231-3292 or fill out the form below to learn about our pest control packages that start at just $19 a month!