What's That Bug? does not endorse extermination

I have a question. What is he and what do I feed him? I found him in
my back yard in Iron Station, NC. He was in the grass by a water
spicket. A mowed yard surrounded by several 100 inhabited woods. I
live in the country. He is very active in late day, night and seems to
be eating grass. His glowing is bright and is 24 hours a day. He is
very beautiful. I would like to know what to feed him so I don’t hurt
him. I am keeping him in a aquarium.
He is slightly fleshy segmented and seems to fold within himself but not
as much as a grub worm or as thin as a centipede. He is around 2.2
inches long when open all the way up and with around 12 segments. His
head is dark gold, triangle shaped with several short antenna and tiny
pinchers. He is very active and glows beautiful neon green in between
each segment and on his side is very bright glowing dots below each neon
strip. Gorgeous when he moves. Absolutely reflects on the grass around
Is it a larva or a worm?
Thanks for your help in identifying him. I think he is unique.
Thank you.
Ivy Baker

We are currently trying to help Ivy identify her beetle grub.

Update:  May 12, 2014
This posting is over ten years old, and in that time, we have gotten much better at identifying the myriad creatures sent to us for identification.  We just received a comment indicating that Michael saw an individual glowing.  Despite two comments identifying this as a Glowworm, we never really updated the actual posting, so we are remedying that now.


What's That Bug? does not endorse extermination
Location: Iron Station, North Carolina

10 Responses to Glowworm

  1. migrlintn says:

    I have found about 10 in my yard over the last few weeks my father in law has lived in this area his entire 56 years and has never seen one im am curious as to what they are

  2. Miss Van says:

    That is a female Phengodidae. The beetle family Phengodidae is known also as glowworm beetles and their larvae are known generally as glowworms. The females and larvae have bioluminescent organs. They occur throughout the New World from extreme southern Canada to Chile. They are uncommon.
    From the University of Florida Website;
    “The family Phengodidae are uncommonly encountered beetles that have bioluminescent females that appear to be larvaiform (or larger versions of the immature stage.) These adult females are able to produce light from paired photic organs located on each body segment (one glowing spot on each side) and sometimes also from luminous bands that extend across the dorsal surface of the body between each body segment. Females appear to be more commonly encountered than larvae. Because these glowing spots along the females body resemble the windows of train cars internally illuminated in the night, they are often referred to as “railroad-worms.”

    Males of these species are not larviform, but instead resemble other beetles, though their first pair of wings (elytra) are less then half as long as their hind wings and the males of most species have very elaborate, feather-like antennae. These fancy antennae are used to detect and follow pheromones produced by the female. ”
    This beetle family (as defined by Lawrence et al. 1999) is restricted to the New World (from the northern U.S. to Chile) with its highest diversity in the neotropics.

    • bugman says:

      Thank you so much for clearing up this very old posting. We have learned quite a bit since it was posted nine years ago, and we would have gotten the identification correct today, but it seems with all the new mail, we do not have much time to clean up our archives. Thanks again.

  3. MJ says:

    To say something is a Phengodidae is a very general classification. I would like to know the actual name of the beetle that this all yellow larvae represents. I found one last night while walking my dog. It was amazing to see. The entire outline of its body glows and there are tiny glowing spots within the outline. It is not a railroad worm, unless the only the males are black and orange, and the females are all yellow. Does anyone know? The worm I found on 8/11/13 definitely looked like the picture here and was all yellow. I live near Pittsboro, NC – which is about 3 hours due east of the original posting for this larvae.

  4. michael says:

    we saw one like this at Shinleaf Campground this past week end, I first noticed it when i tripped on a rock and it popped out of its hole, that evening i walked past the spot and saw it glowing. The kids and i were simply stunned, they of course wanted to keep it but we insisted it be returned. It is simply beautiful

    • bugman says:

      Thanks to your comment, we have updated this more than ten year old posting with the correct identification of a Glowworm.

  5. J T says:

    I found one tonight I Connecticut

  6. MJ says:

    I found those deep in my mulch pile of very decomposed wood chips – not far from Pittsboro, NC. I live in the country too. I don’t think they eat grass. Maybe look up what grubs eat? He would probably like moist old wood mulch…

  7. Wolf says:

    Found one tonight while getting ready for work at 2 AM, crazy bright little lady! Hope we wind up with more of these around, they’re really something.

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