Home / California Has Fireflies! Who knew?

California Has Fireflies! Who knew?

by | Jan 16, 2019 | 15 comments

What better time to start planning a summer vacation than in the middle of a cold (sort of), wet California winter.  If you are doing a little California dreaming right now, why not plan a summer adventure in the beautiful southern mountains.  You might be surprised at what you find.  Like Joshua Oliva, who recently completed his undergraduate studies at UC Riverside, who discovered a brand-new species of firefly while exploring in the Santa Monica mountains, in Topanga. firefly-2466543_640
This tiny creature with its glowing personality, was only about half a centimeter long and it did faintly glow. He (she) has a long way to go to measure up to its East Coast relatives, who, by the way, are larger, more numerous and really, light it up, on warm summer evenings.

USA, TX, Jeff Davis Co.: Fort Davis.Davis Mountains State Park.04-ix-2016

Public Domain Image by Alejandro Santillana for Insects Unlocked Project, University of Texas,  Austin

Contrary to popular belief, California is home to 18 species (soon to be 19). In contrast, Florida has about 56 species of fireflies. Fireflies are nocturnal members of Lampyridae, a family of insects within the beetle order Coleoptera, or winged beetles

Heinz Albers, www.heinzalbers.org(https://creativecommons.org/licenses/by/2.5)], from Wikimedia Commons

Firefly larvae eating a snail, Heinz Albers, www.heinzalbers.org(https://creativecommons.org/licenses/by/2.5)], from Wikimedia Commons

Firefly larva, also known as, glow worms live for about one year, before it turns into an adult and mates.  The average lifespan of adult fireflies is around 2 months. The firefly’s sole purpose in life is to mate and procreate. Flashing each other, the males and females, find the loves of their lives.
In the United States, it’s extremely rare to see glowing fireflies, west of western Kansas, and even the ones that do glow can be very small and their light so faint that it can hardly be seen. But here’s the scoop.

Courtesy of Art Farmer from Evansville Indiana, USA. https://creativecommons.org/licenses/by-sa/4.0/

Courtesy of Art Farmer from Evansville Indiana, USA. https://creativecommons.org/licenses/by-sa/4.0/

Luminescent fireflies also known as lightening bugs, 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.
In general, fireflies prefer wet, humid habitats that  support their favorite food, snails. Those few species that have been discovered in Southern California have been found mostly by ponds, springs, seeps and streams.
Firefly Fun Facts: 

See more fun Pest Toons athttps://www.corkyspest.com/toons.html

See more fun Pest Toons at https://www.corkyspest.com/toons.html

  1. They have strange eating habits. Contrary to the cute image of baby fireflies flitting from flower to flower, the underground-dwelling larvae of the lightning bug are carnivorous and feast on oozy slugs, worms and slimy snails. Once they grow up, some turn to cannibalism and eat other fireflies, but most live on pollen and nectar (while some don’t eat anything during their short lifetimes).
  2. Predators that might crave a “light” meal, beware the lightning bug. They taste disgusting. Firefly blood contains lucibufagins, which is a defensive steroid that tastes really yucky. Predators associate the awful taste with a firefly’s light and learn not to eat bugs that shine.mason-jar-2-3864319_640-1

If your summer, mountain adventure includes firefly hunting, your best bet is to grab a mason jar (don’t forget to poke holes in the lid) and head for an area with a natural water source on a warm summer night. Turn off your flashlight, so you can see their glow.  Be thoughtful.  When you are done admiring these little guys, let them go.  They will thank you for it.


  1. Michelle Telles

    I live in Sacramento, California USA
    I have a mystery in my neighborhood, and I was hoping someone could help me with identifying an insect without a picture. It’s the beginning of winter and 10:00 at night when my neighbor texted me to come look at what appeared to be lightning bugs flying in the tree next door to him. The tree was full of them! Not being my property, we couldn’t get closer in the hopes of catching one. The next morning the tree was full of birds. I’m stumped because, as far as I know, fireflies don’t live in Northern California. (My neighbor and I have lived in California all our lives, and we have never seen them here before.) And what firefly does their light show in the winter?
    Do you have any idea what we saw? I’ve been researching this for days, and I’m stumped. Thanks for any information you can give me.
    BTW: I had to makeup a website to post this.

    • Nancy Schaible

      Hi, Michelle!
      Well, while I was doing some research for my blog last January, I found that California does indeed have several species of Fireflies, eighteen maybe nineteen by now. UC Riverside graduate Joshua Olivia discovered a new species of firefly while exploring in the Santa Monica mountains in Topanga.So it is quite possible that even in northern california (since we have had such mild weather so far) there could be colonies. Weather and other environmental factors could cause behavioral changes. I would love to see these guys so if you could snap a picture do so and email me at nschaible@corkyspest.net. Another insect here in California, that’s been found more in your direction, that has bioluminescence is the Click Beetle. It also can fly and does hide during the day but is active at night. Hope you solve your mystery! Nancy

      • Steve

        I have seen Click Beatles here in N. California but never bioluminescence. How do you tell different species from on and another?

        • Nancy

          The luminescent click beetle is not native to California but does often appear in neighboring states such as Arizona and even Baja California. California is known for the Chalcolepidius webbi click beetle (no bioluminescence) B Size (Adult; Length): 25mm to 38mm (0.98″ to 1.49″) Colors: black; white; blue Descriptors: click; flip; flying; long; slow. The biolumenescent beetle’s Scientific Name: Deilelater physoderus Other Name(s): Jacknife Beetle BeetleSize (Adult; Length): 15mm to 24mm (0.59″ to 0.94″) Colors: brown Descriptors: dusty; click; snap; jump; flip; light; iridescent; glowing; neon; flying.

          Hope I have partially if not fully answered your question.

    • Tyler

      Hi Michelle,

      I live in Sebastopol and saw the same thing in the tops of some eucalyptus. I know fireflies from my summers on the east coast and these looked just like them except that the glow was green, what about the ones you saw? What color was their glow?

  2. Rita Napier Newman

    Dec 25 We’re in Ventura we have fireflies in our elm tree we’ve observed the last 5 nights! Amazing! Most light up green in a linear pattern coming up from the top branches, a few light up red. Friends have observed them in disbelief.
    I also had to make up a website

    • Nancy Schaible

      How special! We are seeing more occurences of these tiny luminescent beetles here in Southern California and scientists are discovering
      new species. Their favorite time to appear is just after dusk but they may appear later depending on environmental conditions.
      Lightning bug lanterns can glow yellow, orange/red or even shades of electric blue. They can appear as single blinks or long, glowing trails. Some fireflies will flicker when threatened by a predator or caught in a spiderweb. Others light up to compete with rivals or after they’ve been rejected by a suitor. Some females are completely dark, while others offer flickers to let males know they’re on the market. Putting all the scientific stuff aside, they are wonderful to behold! Enjoy!

  3. Jerry Gardner

    I’ve lived in Northern California for fifty years and have never seen a firefly. Are they only present in Southern California?

    • Nancy Schaible

      HI, Jerry! The answer to your question is no. Fireflies have been spotted in Northern California but it’s not where they prefer to live. Most Species of Fireflies live east of Kansas. But California
      is home to a few species. Northern California has had dry hot summers as most of California has been consumed by drought. Fireflies like tall grass and warm humid conditions. Loss of habitat and a change in their
      preferred climate and food sources (such as snails) may be decreasing the populations and causing migration to other areas. But maybe not all have moved on. They are still seen after warm spring/summer rains, around
      streams and pools of water. Seeing them may be a challenge since most here in California are not the “brightest lights”. Keep looking!

    • William Farell

      In the ’70’s there used to be the southern variety in Catalina island . I would see them in the park by the casino… Don’t know if they are still there or not…

  4. commercial-movers-las-vegas

    Thank you for the good writeup. It in fact was a amusement account it.
    Look advanced to far added agreeable from you! By the way, how could we communicate?

  5. Angela

    When I was a young child, esrly to mid 80’s they were plentiful st Wilderness Lakes RV resort in Menifee. It had swampy, mossy, man made lakes and dozens of eucalyptus trees. I dont remember flowers or snails. As the area became developed they seemed to disapear.

  6. William Farell

    When I was a kid, my dad & I went to Catalina island every weekend… It wàs such an experience as my dad taught diving for about 3 months at a private college located in toyan bay, north west if Avalon. Long story short, there were firefly’s in Avalon’s park near the casino…
    I was hoping that there still are firefly’s, but can’t seem to find anything on it one way or another.
    Can anyone help me out?

  7. George Roed Larson

    I live in the Barker Hill area of Santa Barbara, This evening, just as the sun was setting , as we looked west to the setting sun, we noticed spots of light on the natural vegetation below our home. We were totally confused as we had never seen it before. We could see them with our naked cye and , obviously, through binoculars………but could not define the source. Just belore sunset,……….the light shut off.. We thought the neighbor had placed holiday lights out, but this did not compute. We will look again tomorrow night. How SPECIAL and unexpected.


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