Dismalites (Glow Worms)

Would you believe that there really is such a creature as a glow worm?  I had known of the existence of glow worms, but I had always assumed that they would look like a white grub.  I had assumed wrong.

Glow Worms glowing from a dark bank (click on the photo for a larger view)
On a warm March night in North Alabama, as my sons and I were walking along a dry stream bed that meandered through the woods near our house, we noticed greenish-blue lights faintly beaming along the dark, damp sides of the stream bank.  We knew that the light wasn't caused by fireflies, as fireflies have a yellowish-green light.  I confidently told the boys that we had found glow worms- but when we tried to get a closer view with the light of a cell phone- we couldn't find the source of the blue light.  In retrospect, I couldn't "see" the source because of my preconceived notion of how a glow worm should appear.

Orfelia fultoni glow worm emerging from its burrow
The next night, my 8 year old son, Shepherd, and I went back to find a glow worm and also attempt to photograph one.  We found them again, high on the stream bank; they were almost exclusively in areas protected by an overhang and where the ground was damp and a little mossy.

It didn't take long to discover the source of the illumination.  It was from a real worm!  Just like an earthworm with a white head or tail!   And as we watched them, we learned that these worms had more cool tricks to compliment its illumination trick.
Closer view of its web lined burrow

The little worm makes a trap for insects from  a sticky, web-like substance and then uses its light source as a method to attract night critters into its trap.  And the worm is very fast.  If my son or I became a too nosy or moved a little too close, the worm would dart suddenly back into its burrow.

A common name for this "glow worm" is Dismalite.  It receives this name from the abundance at which it is found at the Dismal Canyon Conservatory near Russeville, AL.  According to the Dismal Canyon Conservatory's website, the glow worms are so plentiful that "when looking up at the moss covered canyon walls it's hard to tell where the Dismalites stop and the stars begin."

But would you believe that this beautiful worm (I can't believe I just wrote that) is really a fly larvae?  And not just any ole fly: it is the larvae for the Predatory Fungus Gnat.  Sounds scary, doesn't it?  But here's the thing- the adult fly doesn't even have mouth parts!  It doesn't need them. It only lives long enough to find a mate and then die.  The life span of an adult of this species is about 2 days.  The irony is that the larvae of this species live for up to a year.  It must be a bummer to be a worm all of your life and by the time you finally earn your wings you have to die.

An insect that shines a blue light from canyon walls and stream sides must have been discovered hundreds of years ago?  Right?  Nope.  Amazingly enough, these worms weren't officially discovered and named by scientists until 1941.  B.B. Fulton was the entomologist that discovered them near his home in North Carolina..  He named them after himself- Orfelia fultoni.

To learn more about these fascinating creatures, the following websites were very helpful to me:

http://www.dismalscanyon.com/dismalites/index.html
http://www.tn.gov/environment/tn_consv/archive/bluelights.htm
http://www.ncbi.nlm.nih.gov/m/pubmed/17285566/
http://bugguide.net/node/view/67093
http://en.wikipedia.org/wiki/Orfelia_fultoni

Be sure to click on the photos to retrieve a better view.

Shepherd getting a closer look at the Dismalite glow worms

0 comments: