Wednesday, July 16, 2008


Here's some very poor video of fireflies near the Harlem Meer:

It's not great -- it's probably worse than the Mimosa video -- but I couldn't resist. ADDED: For a better video, see the bottom of this post.

Fireflies are yet another telltale sign that we are in the high summer season. I've seen them quite a lot this year -- in parks and even among foundation plantings next to buildings. Perhaps they are more prevalent this summer, due to the mild winter we experienced.

Here's a shot of the actual insect:

Fireflies are in the Coleoptera order, which means that they are related to beetles. The genus is most likely Photuris, though I am not sure if this is Photuris pennsylvanica, the Pennsylvania firefly or P. pyralis, the common firefly. It looks an awful lot like the photos of P. pennsylvanica that I found online, so I am leaning towards the former. The genus name's origin is pretty clear: Photo means light in Greek.

Most fireflies use their light -- due to an enzyme called luciferase -- to attract mates. After they mate, the females will lay eggs just below the ground's surface. The eggs will hatch and the larva will feed for a few weeks in late summer, then burrow deeper into the ground to overwinter. The following spring, the larva feed for a few more weeks before metamorphosing into their adult forms. And so on.

I won't try to explain how this enzyme works -- that's well out of my league. However, the name luciferase is interesting, isn't it? Lucifer, when broken down in Latin, simply means light-bearer. But of course, most of us think of Lucifer as another name for Satan.

This enzyme is also present in the fireflies during their juvenile phase and were the larva not underground, we could see them live up to their name, glow-worm.

ADDED: I just watched the video stream from the site and see my description of "very poor" is hardly adequate. The video below is closer view of the insects, though I won't know if it's any better until I post it. Here's hoping!

1 comment:

Nazardesign said...

We have many of these around our house as we back up to a pond within some woods. Thanks for the enlightening post. With the feeding that you mentioned, are they a threat to particular plants?

I always wanted a glow worm! Um when I was 5...