7th Night of Moth Week

Temple of the Ultraviolet Light, Lake Merwin edition

Tonight I am on the south side of Lake Merwin, about 10 miles east of Woodland, Washington, at about 500’ elevation on a little landing off an old logging road. I’m not too worried about being bothered tonight, because I’m off the main road on public access land owned by Pacific Power and Light. The moon is almost full and doesn’t set until 1am, but that doesn’t matter because there is a steep hillside to the south that blocks its glow. It was 72⁰ at sunset, with almost no air movement, and mostly cloudless skies. 

Iridopsis emasculatum and Herpetogramma abdominalis

I’m surrounded on all sides by a nice 2nd growth forest which either wasn’t replanted after logging, or was done so with the idea of creating a healthy forest, because this is no tree farm. Lots of alder, and  big leaf and vine maple, salmonberry, Doug-fir, and Western red-cedar. It’s also a pretty open forest, and I’ll bet my lights are visible to 50 or 60 acres of territory. I set up two Temples of Ultraviolet Light tonight, the second being up the hill and around the corner of a gated road. It feels pretty secure here, and I’m not too worried about leaving either set up to attend to the other one. 

Eulithis xylina and Lacinopolia olivacea

11:27- Well, I wrote the foregoing and went to check my sheets at 9:20. And there were already at least a dozen moths! And they just kept coming in. At first there wasn’t much diversity, and most of the first couple dozen moths I saw were either Lacinopolia olivacea, Cosmia praeacuta, Macaria signaria, or Herpetogramma abdominalis . Then it really got going, and the last time I looked there were at least 100 moths at each setup, probably representing 15-20 species total. There are so many moths I can’t keep track! It was two hours before I sat down again, because there were new moths coming in constantly. This is what I remember from good nights of mothing!

Eosphoropteryx thyatyroides

12:24- Temperature has dropped to 63⁰, and moths are still coming in, although they aren’t as frenetic, nor as prone to spook when I try to photograph them. The diversity is still not huge, but the numbers are great, with multiple individuals of just about every species I’m seeing. At last count I have 8 Nadata gibbosa (White-dotted Prominent) at one light and 5 at the other, which is at least 4 times as many of them as I’ve ever seen in one night. I had been planning on starting to pack up about now, which would get me home about 2, but this is too much fun, and I’m too wired up on moth madness to sleep anyway. Besides, when it does really cool off, I’ll get my best photo opportunities. And my experience has been that most of the silk moths and sphinx moths show up later in the evening, working graveyards rather than swing shift.  

Clemensia albata above and Properigea albimacula below

2:20- On my last round I found a large orthopteran that I think is probably a shield-backed katydid, but I can’t find a match in my book. I also found several new moths, and I think I’ve found over thirty species to add to the tally. This is so much fun that I’m loathe to give up, but the temperature is down to 57⁰ and it’s gonna take awhile to examine things as I tear down, so I think I’ll take one more walk up the hill to the satellite shrine and at least gather my gear from there. 

Smerinthus opthalmica

3:45- I just got back to the van after taking down the light I had set up further up the logging road. It took awhile, because interesting new moths kept coming in. But I had to take a second and write this down because as I’ve been writing these logs in real time I have made several statements about the way I thought things would go, and many (most) of them have turned out to be wrong. However I was just proved correct on one of my earlier statements tonight, because a big, beautiful sphinx moth, Smerinthus opthalmica , flew in at 3:05, just as I was getting ready to tear down my satellite shrine. Even a blind squirrel…

Hesperumia sulphuraria

Home; 5:53- At last count before I broke down my setups I had 11 Nadata gibbosa at one light, and 10 at the other. That’s a great night of mothing in its own right. And I’d guess there was at least a dozen other species where I had double digit visitors. I tried to count the number of moths on and around the temple up the hill and there were over 150 moths, and I think the lower one had more, although it had less diversity. It was a little after 5am when I started driving home, and when I got out of the trees I realized it was getting light outside. I think that was the first time that I ever mothed through a whole night, at least while remaining conscious the whole time. But I’m beat now, and having a hard time keeping my eyes open to type this. Iced tea, curiosity, enthusiasm, and moth madness can only carry one so far. 

Orgyia antiqua

A very incomplete list of moths that are new for the week and that I found last night, Friday, July 28, 2023;


Herpetogramma abdominalis 


Drepana arcuata (Arched Hooktip Moth)


Clemensia albata

Hypena abalienalis 

Hypena palparia 

Lophocampa maculata (Spotted Tussock Moth) 

Orgyia antiqua

Rivula propinqualis


Caripeta divisata (Grey Spruce Looper Moth) 

Cyclophora pendulinaria (Pearly- grey Wave) 

Eulithis xylina

Hesperumia sulphuraria

Iridopsis emasculatum 

Macaria lorquinaria (Lorquin’s Angle Moth)

Neoalcis californiaria

Perizoma curvilinea

Plagodis phlogosaria

Selenia alciphearia


Tolype distincta


Anaplectoides prasina (Green Arches Moth) 

Diarsia esurialis

Eosphoropteryx thyatyroides (Pink-patched Looper Moth) 

Melanchra adjuncta

Properigea albimacula

Zotheca tranquilla


Oedemasia semirufescens

Schizura ipomaeae


Smerinthus opthalmica 

These 28 bring the total up to 81 for the week, and I found at least ten more species last night that I haven’t positively identified. 

Zotheca tranquilla

10 thoughts on “7th Night of Moth Week”

  1. Dan, been avidly reading your descriptions each evening and I just wanna say thanks for taking the time to pen them (in situ, in the thick of the action!) as I’ve gleaned a good number of tips and tricks for my own mothing efforts. Especially appreciate these last two days (6 & 7), the lows and highs, the conjecture about the environmental influences that could so drastically change moth abundance, how stark of an impact that forestry spraying has when you stop to check out the moths (I understand that is merely a hypothesis on Day 6, but an important one to air). Maybe next year I’ll have to see how rural Pierce Co stacks up against Clark Co. In the meantime, holler if you’re ever open to a fellow naturalist joining to learn and hone mothing skills. Xantharhoe labradorensis vs. packardata was one of the first moth ID wormholes I visited, and I believe my conclusion was the same as yours. That moth showed up on the wall of our house at the time, no light required! Anyway, thanks for this moth week odyssey.

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