A never-before-seen species of firefly was just discovered in the Santa Monica mountains, in Topanga.
It’s just a little guy — about half a centimeter long. It does glow, but faintly. Experts say it has nothing on its beaming East Coast cousins that light up lawns on warm summer evenings.
But the new discovery is still thrilling: It means that contrary to popular belief, there are fireflies in Southern California.
Entomologists have known about fireflies in our region for a long time, but they say they are rarely seen and are difficult even for the professionals to find.
Doug Yanega of the Entomology Research Museum at UC Riverside said the museum has fewer than 30 local firefly specimens in its collection.
To put that in context, the entire collection has about 4 million bug specimens, and it goes back 100 years.
“So that’s all we found with all the students, staff and faculty collecting over the past century,” he said. “You really have to be at the right place at the right time.
Firefly expert Marc Branham of the University of Florida in Gainesville said there are 18 known species of fireflies in California, compared with 56 species in Florida, and 2,200 described species worldwide.
“As you go west in the U.S., there are many fewer fireflies, and in short, we don’t know why,” he said.
He added that many of the fireflies on the West Coast are bioluminescent only when they are in the larval stage. By the time they grow into adulthood, they no longer glow.
“West of western Kansas, it is very rare to see flashing fireflies,” he said. “And even the ones that do glow can be very small and their glow can be so faint that it is difficult to see.”
But there is still hope. Luminescent fireflies have been seen in the Santa Monica mountains and the Laguna mountains in San Diego. They’ve also been spotted on the southeast slope of Mt. San Jacinto and upper Lytle Creek in San Bernardino County.
“They are probably in lots of other spots, but we don’t have good maps of species distribution,” Yanega said.
In general, fireflies prefer wet habitats that better support snails, their favorite food. Those few species that have been discovered in Southern California have been found mostly by springs, seeps and streams.
They also seem to be active only in the summer months. Yanega said every single firefly specimen in the museum’s collection was caught between May and July.
The new firefly species still has to be named and officially described. It was caught by Joshua Oliva, who recently completed his undergraduate studies at UC Riverside.
Yanega is not revealing the exact spot where the bug was found, but said it was in a fairly developed area of Topanga Canyon, where a natural low spot in the ground gathers water on a temporary basis.
If you’d like to go firefly hunting yourself, your best bet is to head for a natural water source on a summer night and turn off your flashlight so you have a better chance of seeing a glow.
“I don’t know of any place that is a predictable spot though,” Yanega said. “There are probably a lot of places where you might see them, but if it was predictable, it would be better known.”