The firefly was officially named the Pennsylvania state bug in 1974, thanks to an effort by elementary students in Upper Darby.
While there are thousands of bugs residing in Pennsylvania, the firefly was chosen for its beauty, behavior, and cultural impact. The firefly has become one of the most recognizable symbols of summer in the Keystone State.
On warm evenings, their soft glow drifting across fields, forests, and backyards is instantly familiar. Fireflies play a meaningful role in local ecosystems, and their decline is an early warning sign of broader environmental stress.
Understanding what fireflies are, how they earned their designation, and what threatens their survival helps Pennsylvanians protect a species that’s both scientifically fascinating and deeply tied to local identity.
Why the Firefly Is Pennsylvania’s State Bug
The firefly officially became Pennsylvania’s State Bug in 1974, thanks largely to the determination of elementary school students from Upper Darby. These students organized petitions, engaged legislators, and rallied public support to promote the firefly as a symbol of the state.
Their reasoning was simple and powerful: fireflies are harmless, helpful, widely recognized, and uniquely associated with Pennsylvania summers. Governor Milton J. Shapp signed the designation into law on April 10, 1974, giving the firefly a permanent place in state history.
What Exactly Is a Firefly?
Despite their name, fireflies—also known as lightning bugs—are not flies at all. They are beetles belonging to the family Lampyridae. Most adult fireflies measure under an inch long and are dark-bodied with yellow or orange markings near the head.
What sets them apart is their ability to produce light through a chemical reaction called bioluminescence. This reaction occurs in specialized abdominal organs and produces light with almost no heat loss, making it highly energy-efficient.
Different species use unique flash patterns to communicate, particularly during mating. Some blink in rapid sequences, others glow steadily, and many species can recognize only their own kind by these patterns.
Fireflies: The Surprising Predator
While fireflies are typically thought of as gentle glowing creatures that light up the night sky, their nature is quite different.
They are beetles, after all, and they are classified as predators. While some firefly species do feed on flower nectar, most of them are on the prowl. They make surprisingly good pest control experts themselves.
Firefly larvae feed on other invertebrates, such as snails, slugs, and worms. Having them around can keep your garden pest-free and promote mushroom production.
Between their glow and hungry young, they should be welcome in your garden. The females, however, tend to eat the males; so, courtship can be dangerous.
While they can be harmful to other insects and each other, they aren’t harmful to humans.
Fun Facts about the Firefly
Fireflies, or lightning bugs, are not actually flies, as the name implies. They are actually a part of the beetle family.
These small creatures are about ¾ inch long and mostly black. You can identify these well-known insects by the two red spots on their headcover. Their headcovers and wing covers are both lined in yellow.
They have two antennae, six jointed legs, and, like most insects, a hard exoskeleton. Of course, the most unique aspect of a firefly is its glow.
A firefly’s glow produces light by way of a chemical reaction using special organs. This light emits very little heat to avoid wasting energy. Either sex can use its glow to attract mates, and their flash patterns are particular. In fact, the signals vary from species to species. Some emit a continuous glow while others use “flash-trains” to attract mates.
Mainly a summer insect, there are over 136 different types of fireflies. Their distinctive glow can be white, yellow, orange, green-blue, or red.
Why Are Firefly Populations Declining
Though fireflies have always been a beautiful memory from childhood, the sad fact is that these glowing creatures may be fading into memory. Our state bug is experiencing a steep population decline.
This decline in numbers can be traced to habitat loss and degradation, in addition to light pollution, pesticides, climate change, and over-harvesting.
If we aren’t careful, we could very well lose these useful and beautiful insects. Hope is not lost, however. There are plenty of things you can do to help promote population growth, and you can do it in your own backyard.
How You Can Help Protect Fireflies at Home
To encourage fireflies, the easiest thing you can do is turn off the lights. By turning off your lights at night, both inside and out, you can cut down on light pollution and encourage fireflies to seek shelter in your yard or garden.
Another easy way to promote fireflies is by providing their favorite food–you can do that by maintaining a garden full of flowers and vegetables. Fireflies actually feed on snails, slugs, and earthworms that inhabit garden beds.
To build their population, you can give them a place to shelter while they enjoy a beautiful garden. Just be careful of pesticides.
Additional steps homeowners can take to protect fireflies include:
- Turning off or reducing outdoor lights at night
- Using motion-sensor or warm-spectrum lighting
- Leaving some leaf litter or natural ground cover
These steps create safer conditions for fireflies to feed, breed, and thrive, often without any added cost or effort.
Fireflies on a warm summer night are as strong a memory as street bazaars, ice cream trucks, and county fairs. Unfortunately, without help, our state bug may just become a memory.
Helping these little glowing fellas out is pretty easy; it’s as simple as flicking a light switch.
Take the time this summer to turn off the lights, sit in a quiet place, and watch the fireflies glow. They are the state bug, after all, and they sure know how to put on a show.
FAQs
Why are fireflies Pennsylvania’s state bug?
They were chosen in 1974 due to their harmless nature, cultural significance, and statewide recognition. Their glowing displays are strongly associated with Pennsylvania summers and childhood memories.
Are fireflies actually beetles?
Yes. Fireflies belong to the beetle family Lampyridae, not flies. Their hard wing covers and life cycle are typical of beetles, even though their name suggests otherwise.
Do fireflies help control pests?
Yes. Firefly larvae feed on slugs, snails, and other garden pests. This makes them a natural form of pest control in yards, gardens, and wooded areas.
Can fireflies harm humans or pets?
No. They are harmless to humans, though some animals should not ingest them. Fireflies contain defensive chemicals that can be toxic if eaten by pets like dogs or cats.
Why don’t I see as many fireflies as I used to?
Population declines are linked to habitat loss, light pollution, pesticides, and climate change. These factors disrupt breeding, feeding, and larval development cycles.
What time of year are fireflies most active in Pennsylvania?
Late spring through mid-summer, especially during warm, humid evenings. Activity typically peaks in June and early July.
Does outdoor lighting really affect fireflies?
Yes. Artificial light disrupts mating signals and reduces reproductive success. Even small amounts of excess lighting can significantly impact local populations.
Should fireflies be removed if they’re near my home?
No. Fireflies are beneficial and should be protected, not removed. Creating a firefly-friendly yard helps preserve an essential part of Pennsylvania’s ecosystem.
