Porch Light Bug Viewing – Who’s Watching Whom?
Some of you might cringe at the idea of standing below a porch light while an eclipse of moths (yep, that’s what a group of moths are called) are whirling and gyrating around your head. I find it fascinating, even as they hit at my face or hair, before bouncing back towards the light or disappearing off in the dark night.
Camera in hand, I wait for them to settle on the wood siding beneath the glow. Stealthily, I focus my lens to capture the delicate shimmer of scales and patterns, or eyes and antennae of my subject. Last night, I actually felt I was the one being observed.
This particular moth is in the genus Hypena. The species is Hypena decorata. It is a medium sized (15-18mm), somewhat drab moth. This species is sexually dimorphic – meaning the males look differently than the females. Males are slightly larger than females, with sooty brown forewings marked with two white spots near the apex or bottom edge of the wing.
Females of this species are more mottled in coloration, some with a purply hue. They also have a small patch of raised dark scales in the median area. More about distinguishing male and female specimens can be accessed here http://pnwmoths.biol.wwu.edu/browse/family-erebidae/subfamily-hypeninae/hypena/hypena-decorata/
On occasion, there can be an odd form, like this one I found in August of 2019 https://buggingyoufromsanjuanisland.com/2019/08/22/hypena-decorata/
Food/host plants for Hypena decorata are nettles (Urtica spp.) in the Urticaceae. These moths range from BC to Southern California. There appears to be two broods per year (April and August). Adults come to lights and can be found flying from April to September.
While this may appear to be merely another drab, ordinary moth, I want to show you the photos I took of the male and the nearby female last night. I missed it when I first went through my photos, but the second time around, it definitely appeared that the male moth was turning his head to watch me. Sort of like how Drago, my dragon lizard will do the same thing.
It’s a mysterious world, and much more rich when we recognize we aren’t the only ones that are aware. Some humans (I’m ashamed of researchers for this) do horrible things like cut off moths antennae to try and figure out how they fly (or can’t fly after being mutilated in this way). If we could only recognize they have a desire to live, find mates, food, and shelter – just like humans, maybe we would care more.
References and Further Reading
Bradley H. Dickerson, Zane N. Aldworth, Thomas L. Daniel; Control of moth flight posture is mediated by wing mechanosensory feedback. J Exp Biol 1 July 2014; 217 (13): 2301–2308. doi: https://doi.org/10.1242/jeb.103770
Bugging You From San Juan Island (Hypena decorata) https://buggingyoufromsanjuanisland.com/2019/08/22/hypena-decorata/
Pacific Northwest Moths (Hypena decorata) http://pnwmoths.biol.wwu.edu/browse/family-erebidae/subfamily-hypeninae/hypena/hypena-decorata/
Thompson, A. 2007. Mystery of Moth Flight Uncovered. LiveScience https://www.livescience.com/4338-mystery-moth-flight-uncovered.html
Author’s note – When it comes to experimenting on living beings, the aim of science shouldn’t always be to prove a hypothesis. Sometimes we need only to experience the extraordinary wonder of meeting the spirit within some of earth’s most unassuming characters. Be kind to those around you. Even the ones with scales and chitin.