Putting on Your Moth Goggles

ALLEN FISH: Birders use the term “spark bird” to talk about the species that got them started. Do you have a spark moth? And why are moths exciting for you?

CAT CHANG: The omnivorous looper might have been my spark moth. I found one in the bathroom at USF, so I took a photo, sent it to Liam O’Brien, and said, “Look at this cool thing!” Liam told me about it. He mentioned the form cottlei, which is the dark morph found only in the Bay Area. It’s almost a chocolate color. But most of the omnivorous loopers are light forms, like the one I found.

AF: The two color-forms remind me of the 19th century accounts of the peppered moths in London. As industrial factories sent soot and other pollution into the air, and tree bark got darker, the darker form pepper moths became more numerous than the light ones. I wonder if a similar event happened in the Bay Area.

CC: We need to look into that. I would say [the looper] was the spark moth, but the part about moths being exciting—just standing at a moth sheet at night with a flashlight and seeing them up-close—they’re just so damn cute. They sit there and look back at you, and you can slow down and study what this thing is. Whereas with butterflies, they often fly away. 
Sometimes you catch their eyes with your headlamp or flashlight and they glow back at you. They look a little befuddled, like, why am I here? 

AF: The corollary question is do you have a nemesis moth, an elusive species that you’d most like to see? 

CC: I’d love to see Adela oplerella. Adelas are fairy moths. Oplerella was named for the Bay Area lepidopterist Paul Opler, and its host plant is creamcups, a small pale poppy that sometimes is found on serpentine soils. There are only a few places in the Bay Area that Adela oplerella have been found—a population at Ring Mountain and another near Coyote Ridge Open Space. I’ve been looking for these Opler’s fairy moths, and I can’t seem to find them. Welcome to the next chapter of your moth journey, and that is learning your plants. 

AF: So noted. Do you have any bits of advice for me, as a brand new moth-er?
How do you not become overwhelmed trying to learn the thousands of moth species just for California?

CC: Well, I think denial is important: to start, just focus on the moth that’s in front of you. And maybe try to see some of the day-flying moths first. For night-flying moths, Damon Tighe uses a very portable moth set-up—an LED UV-light strip that plugs directly into a chargeable battery pack—and then he just hangs up a lightweight sheet next to it. Damon even uses a white t-shirt on a hanger. That’s all you need for a moth-light. 

You can also take a box or bucket with an opening at the top, fill it with egg cartons, and put the UV light on top. The moths go down into the egg cartons and just go to sleep. When you wake up in the morning, open the container and photograph the moths. I did once leave a sheet up all night and in the morning, I found scrub jays eating moths off the sheet. The jays were very happy to eat what was on the smorgasbord. 

AF: When they see the purple UV lights, my family thinks there’s an alien landing nearby. As a moth trapper using sheets or buckets and releasing moths back to the wild, do you think it’s a problem for the moths?

CC: To some extent, yes, because we are interrupting their mating, right? But you could argue that maybe we’re facilitating their meeting too, because they’re all coming to the light. I’ve seen that on the sheet where, um—moth sex is happening. 

But if you trap too much, you might disrupt the moths’ distribution patterns. I’ve heard professional lepidopterists talk about that a little bit, but they are using much more powerful tools. Some of the mercury lamps are probably pulling in moths from a couple miles away.  And some professionals use pheromones. Moths can sense the pheromones from greater than two miles distance. 

AF: I want to circle back on day-flying moths. Night-time moth-lighting has been my main practice. How do people find day-flying moths? How do you train your eyes to find them? 

CC: You need to focus your attention in a specific way. Adjust your attention to the surfaces of grass and shrubs, and scan for small, flitting movements. Think of it as  putting on “moth goggles.” I took a friend of mine to see a Western pygmy blue [butterfly]—Brefidium exilis—one of the world’s smallest Lepidoptera. Its host plant is Atriplex family members such as Russian thistle and likes halophytes in marshy alkali areas. 

But it’s only a half inch across, and he’d never seen it until I showed it to him. He took a minute to see it. Well, yeah, it’s one of the world’s smallest butterflies. So yes, you’re kind of getting at something—you have to put your small butterfly goggles on. 

AF: When native plants are blooming, especially in clumps, and it’s a warm day, it helps to be still, near a clump of flowers, and to just watch to see if something is flying around, right?

CC: Yes. Jerry Powell would also use his butterfly net to sweep just above or around the vegetation, to get moths and insects to rise, not to catch them, but to make a little disturbance. Jerry used to admonish me and Liam. He’d say, “That’s a net, not a fashion accessory.” Yes, your net is a tool, however, we were more interested in photographing the moths and butterflies. 


AF: So, I don’t need to run out and buy a butterfly net?

CC: I don’t think having a net is helpful for a new moth-er because all local, county, state and federal parks require permits for you to catch native insects. And you need landowner permission to net on private land. But once you get to that point where a net is useful—and you have the permits—it opens up another chapter in your mothing journey. But to get started, just get out and look.

AF: What are some great references or resources for learning about moths?

CC: As far as web resources go, iNaturalist is great; the Moth Photographer’s Group website is great. I go to the Lepidopterists Society open houses; it is nice to meet other people who are passionate about moths, to listen to experts talk about moths. 

AF: I’m curious how you got on the naturalist’s path. Is there a particular place that you got started, that you feel rooted in the earth?

CC: It would definitely be Hawaii, on the Big Island, where my family is from. The Kona side. But I also have a soft spot in my heart for Volcano. Just because it’s such a big deal. You’re right by the park. 

AF: One of the challenges for me in moth work, has been to see small, to adjust my attention down to these sometimes very small insects. Any thoughts on that?

CC: Yes, some of the tiniest ones are the most intricate, with detailed patterns that I’m just amazed by. Some moths are smaller than rice grains, and yet you still have pattern and colors. It reminds me of birders who ignore little brown birds. I get frustrated with that. They’re not that hard to figure out. It’s practice, work, and effort. These small birds and moths each have their own little thing that they do, and by ignoring them, you’re missing out on understanding a giant part of the ecological story.

AF: While we’re talking about teeny little moths, I’ve done almost 95 percent of my moth work with my iPhone camera. Do you use your phone? Do you have a serious DSLR and macro-lens set-up?

CC: So, I have my phone camera and a clip-on magnifying lens. It helps especially with the tiny, tiny moths. I was out with Ken-ichi Ueda looking at moths, and I’m taking a picture of a moth with my phone, and he says, “What if you tried a real camera?” I’m like, “no. I’m happy.” 

For amateurs, iNaturalist is a critical part of the process of documenting moths, because you need that, you need to close the feedback loop. You see the organism, you take the photograph, and then there’s some more knowledgeable moth person, hopefully, who steps in to help you out.

AF:
Are there moth-plant relationships around the Bay that are particularly fascinating for you? 

CC: I found a beautiful moth in a spider web on Mount Diablo. It had already been predated on, so the wings were just moving around in the wind a bit, and the color pattern—white-ish with yellow bars—was so weird for a moth. I took a photo of it, of course, put it on iNat, and everyone said, “this moth is super rare.” It had only been seen in Sonoma and Yolo County, and the host plant is Ash (Fraxinus spp.). Cal Academy entomologist Chris Grinter asked me if there was Ash on the mountain. There is California ash, Fraxinus dipetala, which isn’t a tree, but it is an Ash. The moth Philtraea latifoliae wasn’t known to host on California Ash, but it’s not a hard stretch to think that it might be its host. Chris said he had been looking for it, to no avail, but that same summer, two more people saw latifoliae on Mt. Diablo. So, it must have been a good year for it.

AF: I’ve been wondering where the big knowledge gaps are in moth ecology. 

CC: For many moths, there’s way more mystery than there is story, especially for the tiniest ones. And that was probably why the late Cal entomologist Jerry Powell was so interested in microlepidoptera. This is where we’ve got the most to learn. 

AF: Do you have some places that you like to go day-mothing?

CC: Pinnacles National Park is always good—there’s lots blooming in the early spring. Also Ring Mountain near Tiburon, and Mt. Diablo. Just stand in front of a blooming plant with sun on it, and just slow down, and put on your moth googles.