Texas Fireflies Doing A Disappearing Act, Say Researchers

They’re called fireflies, lightning bugs, glowworms and other names, but one thing they are not called in recent years is plentiful. You can still find the flashy bugs in many areas of the country, but in Texas you might have to do some serious searching, say two Texas A&M University researchers.

Entomologists Ed Riley and Bart Drees say the past few years have dimmed the lights of the flashy insects, once seen almost nightly throughout the state during spring and summer months.

“There’s no doubt the severe drought the past few years has affected them,” confirms Drees, who is a Texas AgriLife Extension Service entomologist. “The lack of water has to be one big reason why you don’t see as many as in years past, but there are probably other reasons, too.”

“Most insects need a certain level of moisture in their environment,  so the drought can play a big role in their numbers,” adds Riley, a curator for the entomology department with a joint appointment with Texas AgriLife Research.  “But another likely reason is urbanization – most insects need natural settings in which to live such as woods, meadows and creeks.  In places where you have a lot of homes and concrete, you will find fewer insects, and lightning bugs certainly fall into that category.”

Both experts say there has been very little research over the past decade to determine why there appears to be fewer fireflies, which are technically members of a family of beetles and not true flies. Many Texans can recall summer months of catching the bugs and placing them in a jar to admire their glowing abilities. But too many children today are stuck with an empty jar.

“Some theories are that fire ants are partly to blame because they can destroy them (lightning bugs) in the early development stages,” says Drees. “As to whether pesticides are to blame, it may be possible but there is no definite proof.  There are just not that many scientific studies to look at to come to one definitive answer.”

Residents of East Texas probably have a better chance of seeing them, as do persons who live in the Midwest, South and Northeast United States, where fireflies remain in abundant numbers.

There’s no doubt they are interesting bugs.

Fireflies produce a chemical reaction inside their bodies that allows them to light up. This type of light production is called bioluminescence. The flashing — both males and females light up — is a huge neon sign to other fireflies that it is time to mate.

But some species use the flash for a more sinister reason — dinner time.

“There are some species of the flashing beetle that flash to attract others so they can eat them,” Riley notes.

So some fireflies aren’t sure if it is time for romance or time to be lunch, and the bugs don’t have much time for either, since they live as adults 7-14 days at the most, the experts explain.

“I have lived in this area for almost 25 years, and I have never seen very many of them in town,” Riley adds. “It’s a question that seems to come up very frequently, but there seems to be no real answer.”

For persons wishing to learn more about fireflies and other insects, Drees recommends visiting insects.tamu.edu.