What's That Bug? does not endorse extermination

Subject: Red and black beetle on coast live oak
Location: San Luis Obispo, CA
September 1, 2013 12:09 pm
Found this large beetle investigating the trunk on a coast live oak at the San Luis Obispo Botanic Garden.
Signature: Linda Eremita

Ha, I figured it out. It’s the adult California Glowworm.

California Glowworm

California Glowworm

Hi Linda,
Though California Glowworm is the common name for
Ellychnia californica, this beetle is actually a Diurnal Firefly.  We believe this is the first image of an adult California Glowworm posted to our site.  According to BugGuide it is found:  “Throughout CA, but seems to be more common from Sacramento south to the San Bernardino Mountains” and the habitat it favors is “on flowers and grassy vegetation, esp. in moist habitats.”  We sometimes get images of Glowworms from California, but these glowing larvae are in the family Phengodidae.

What's That Bug? does not endorse extermination
Location: San Luis Obispo, California

14 Responses to California Glowworm is really a Firefly

  1. Mitchel says:

    I live outside of Redding in northern CA. I found a little bug in my lawn that was glowing neon green like a little peace of glow stick. I was night time and totally stood out in the dark. Been here all my life and never seen one before. Is this normal?

    • bugman says:

      Most California Glowworms are reported from higher elevations. They are present, but not necessarily common.

  2. Dorothy Hampton says:

    We have them here on the humboldt coast also. We used to take our son out at night to look for them. They seemed to like cold moist areas.

  3. Gregory N Parker says:

    In Redding California I occasionally come upon a small worm (or larvae) about 1/4 of an inch long and it has a spot on it that glows lava red at night. I always wonder when I see one ( is that an unextinguished cigarette cherry? ) I have only seen 3 in my 30 years up here. very cool!

  4. John-O says:

    i found three tonight. pink body with a green glow on it’s tail. I’m in Pollock Pines, El Dorado county Ca. I’ll try to get some photos.

  5. Gary says:

    I found two pink Body and neon green lights on their tails. They have appear the last four nights in the same area at our place in Guerneville CA

  6. Katryn says:

    I’ve found one in the yard under the redwoods in eureka. It has two green fluorescent dots that look like glowing eyes.

  7. I live in Sly Park Hills in Pollock Pines. I was outside in the dark looking for the BIG full moon. Looking up into our sentinel trees when I noticed literally hundreds of blinking lights. Thought it might have been stars blinking through trees, but on closer observation they we’re something flying. This is December 3, 2017 – NOT June or July? What am I seeing?

  8. Fred says:

    I think I just found one of these little critters as I was coming back into the house. We live at just over 2000 ft about an hour west of Redding, CA. I looked down and there was a neon green light at just above ground level. It was emitting light not just reflecting it from an unk source. It was on piece of dry grass which was holding above the ground. I picked it and brought it inside to show my wife. Then tried to look it up on the net. It seems very similar to California Glow worm including the orange body. Alas it is dead now. I appear to have squeezed its body when i picked it up and brought it inside. It was no my intent to kill it so that’s sad.

    • bugman says:

      Fireflies do not have the hard, protective exoskeletons that most insect have. They are soft-bodied beetles.

  9. Jeff says:

    A friend of mine found one of these in Cottonwood, Ca., yesterday, just South of Redding, Ca. The one with a pink body with a green glowing head or tail. Cottonwood is in the valley at below 500′ elevation. I see all these responses are within the last two years. Makes me wonder if this species is on the rise. I have never seen one in my 25+ years in the area, nor in my 45 years living in California.

  10. Rose says:

    Not the same species but since we’re talking about glowy things in Northern California, we found what appears to be a railroad worm (genus Phrixothrix) tonight-looks like the one on Wikipedia but it only has ONE row of lights down it’s back. As far as we can guess from info on the web, might be a Mastinocerus.
    We’re 1/2 SW of Red Bluff at 550′ elevation. Lived here for 8 years and this is the first glowing thing we’ve seen. I hope they’re on the rise-I wonder if it’s because we had such a wet winter (41″ when 25-28″ is normal…)

  11. D.mack says:

    Found a pink worm with brown accents about 5/8″ long with a greenish light. Big Bear Lake, CA, 7000′ level.

  12. C. Finigan says:

    We saw a green glow worm in Trinidad, CA.
    C. Finigan

Leave a Reply

Your email address will not be published. Required fields are marked *