Just when I think I have a good grasp on what Eaton Canyon has to offer, something new astounds me. On the first Moonlight Walk of the season, word passed along that we might encounter glowworms. Envisioning long, glowing worms, I couldn’t wait to see them.
And there, under a beautiful moon on one of the rock walls in the Nature Center’s parking lot, was a brightly glowing green dot. Closer inspection revealed a pink-colored segmented insect with a luminescent body part called a lantern, located on the lower abdomen. It was a California Pink Glowworm, Microphotus angustus. And it was not alone. A brief look around revealed at least ten more.
This ½-inch creature is no worm. She is the adult female version of a type of firefly, and a member of a family of beetles known as Lampyridae. While both sexes start off their lives as larva, the adult female retains her juvenile-like shape, known by entomologists as a “larviform.” The male, on the other hand, transforms into a winged beetle. The male, at ¼-inch, is half the size of the female and has very large eyes for his size. All the better to find the glow of a beckoning female.
Living under leaf litter during the day, the females emerge at night, showing off a constant green glow to attract a mate. This green glow is a form of bioluminescence, which is a chemical reaction that emits light without heat. Their Latin genus name Microphotus says it all: “micro” meaning small and “photus” meaning light.
Female glowworms have only about 10 days in their brief life to mate. According to iNaturalist.com, a citizen science Web site, we should be able to see them here in the Canyon through July and into early August.
When the females are not a-glow, they are off in the leaf litter paralyzing and eating their favorite foods: centipedes, millipedes, and the occasional snail. The idea of a ½-inch larviform taking on a four-inch millipede conjures-up an impressive battle.
During Moonlight Walks in the Canyon this summer, allow you eyes to adjust to the darkness and you’ll be amazed by what’s glowing on around you.
All Photos by Phil Hopkins
Source material:
Insects of the Los Angeles Basin, Charles Hogue, 1993
Medium.com, Ranger Jelly, Channel Coast District State Parks, 2013
What are glowworms? Bay Nature, Michael Ellis, 2010
Credits:
Phil Hopkins