6/20/2024 Photo of the Day - Lucy in the Woodland with Diamonds - Black Firefly

 

18 June 2024- 

While surveying vegetation, we very frequently end up surveying for invertebrates as well. Much to the dismay of my camera storage, I encounter a new bug almost daily. This one is pretty recognizable, but may seem less familiar while the sun is shining! A quick search confirmed the ID of this beetle: it is a woodland lucy/black firefly! But why is it awake? Hanging out at 1:30 pm on a Tuesday does not seem particularly exciting for something with bioluminescent capabilities. As it turns out, woodland lucy adults don’t glow! These beetles spend the day eating pollen and nectar; they use pheromones to attract a mate since they do not bioluminesce at night. The adults may not glow, but they are still called fireflies for a reason…

The juveniles emit light! Juvenile fireflies glow as a warning to predators that they will not make a tasty snack (they produce defensive steroids). Like many other invertebrates, fireflies are threatened by loss of habitat, pesticides, climate and seasonal changes, and light pollution—you will have the best luck seeing these lovely beetles in more secluded areas and parks!

- ks 🪲

Want to read more? Check out these articles and sites:

OSU Article on Flameless Fireflies
MN DNR letter from the editor about fireflies
Scientific American article about why fireflies light up
The 175 firefly species of the US and Canada
Shunning the night to elude the hunter: diurnal fireflies and the “femmes fatales”
Bioluminescence in firefly larvae: A test of the aposematic display hypothesis (Coleoptera: Lampyridae)