160 species of butterflies call the Pacific Northwest home. And two researchers have photographed nearly every one of them in their new book, Life Histories of Cascadia Butterflies. The book chronicles every life stage of 159 species, with macro-images of each insect. That’s what makes it special. No other book in the world has this many detailed images of butterflies. Washington State University entomologist David James co-authored the book with Seattle-based naturalist David Nunnallee. James reared many of the butterflies in his house over about 10 to 15 years.
EarthFix: What exactly did you hope to accomplish with “Life Histories of the Cascadia Butterflies”?
James: It was our aim to discover and look at all the life histories of butterflies in this part of the world. A lot of the species are well known as adults, but there are a lot of them that are pretty much unknown as immatures, or caterpillars. A lot of them have never been photographed before.
We wanted to do that to provide photographs of all the immature stages of these butterflies, but also to find out more about their biology and rearing them, to find out about the plants that they feed on and the adaptations to survive in different seasons.
EarthFix: What gave you the concept for the book?
James: That goes back a long way for me. I actually became an entomologist because I liked butterflies when I was 8 years old, would you believe? Many decades ago.
When I was 8 years old, I caught butterflies, and I actually – horrors upon horrors – pinned a few. But that lasted for about a week. Then I realized that I was far more interested in collecting caterpillars and watching them develop into chrysalises and turn into butterflies. So the life history thing has been with me since I was a child. It’s been a lifelong adventure, really.
This was a joint effort. It was quite remarkable how we got together because we both commenced this project independently. I was working in eastern Washington, and unbeknownst to me, coauthor David Nunnallee was working in western Washington. We didn’t know about each other’s enterprises until people we were working with suddenly realized that, ‘Hey we should put these two guys together.’ It wasn’t until 2005 that we pulled our resources, so to speak.
EarthFix: What are the different life stages exactly?
James: All butterflies go through four stages. The butterflies lay eggs on the host plants that caterpillars feed on. The eggs hatch into caterpillars.
The caterpillar is quite an involved stage. Their skin gets tight, and they have to grow to a second, third, fourth and sometimes fifth stage. They differ very much in the coloration and features during those different stages.
To date, if you get a book on caterpillars, you generally find books with just mature, fifth-stage caterpillar. What we’ve done is provide pictures of all the different stages of caterpillar for all the different butterflies, so that even if you find a young caterpillar, you should be able to identify it.
Then caterpillars turn into the chrysalis stage, or pupae, and then hatch into the adult butterfly.
EarthFix: How did you go about looking for so many different species?
James: This work took a decade or more to do, with both myself and coauthor David Nunnallee working. In most species we collected the adult female and got them to lay the eggs and rear them through.
In some species we did actually find the caterpillars in the wild, but it’s a lot hard to find them than it is to find adult butterflies flying around.
These 159 species are found in a variety of habitats. There’s common species that you can find in cities and backyards. Those are the easy ones. But for the difficult ones, some only occur on the tops of mountains, along rivers and various other places. So we had to research where these butterflies live and then find them.
In a couple of instances we cheated somewhat, where the species occurs in the Pacific Northwest, but it was so hard to find them here that we went to places like California, where they are a bit more common.
EarthFix: Are there butterflies in the book that are unique to the Pacific Northwest?
James: Yes, there are a number of butterflies that are unique to the Pacific Northwest. The book does cover a lot of butterflies that occur throughout the U.S. and even internationally. But there are probably six at least that occur only in the Pacific Northwest.
Some of these are quite rare. There’s an example of a brown butterfly that only occurs in the Pacific Northwest. And that’s an example of a butterfly that hadn’t been reared and documented before.
EarthFix: Was that exciting to get photographs that people may have never seen?
James: Yes, that was a great thrill to actually photograph a caterpillar that’s never been photographed before and may not have been reared before. And we’re not talking about the Amazon jungle or anything. We’re talking about the Pacific Northwest.
It’s quite remarkable, really, that you can have butterflies in a well-populated human area that haven’t been discovered in their immature stages before. And to make that discovery and photograph them and present them in a book, yeah, that’s exciting.
CONTINUE THE CONVERSATION
Searching out the butterflies was a family affair. James often brought along his wife and two daughters. Here he talks about more stories from the trail and his favorite butterfly species.
EarthFix: Do you have a butterfly that was your favorite to photograph?
James: There was a number, really. There’s a species called the California Sister butterfly. This species is quite remarkable in its caterpillar stage in that it does some very strange things to protect itself from predators.
For example, if you disturb it, it will actually rear up on its hind legs, which actually really isn’t true. But it actually rears its front end up and bears its fangs. You can actually see its mandibles. It displays them to scare the intruder away.
As a very young caterpillar, it has this very strange feature of collecting its own frass, which is its droppings. And actually constructing little platforms for it to sit on. So you get a leaf where the caterpillar is on, and it’s made an extension to the leaf made of its own frass.
It just lies on the extension and appears to be more camouflaged in that way, or maybe there’s odors from the frass to deter predators away. But it’s a very strange behavior that we think is being developed to prevent predators from attacking it.
We found for a lot of these species, these adaptations hadn’t been described before. An important part of the book is that we’ve catalogued strange things that we’ve found and subjects that should be researched further.
EarthFix: Was there anything that you would be particularly excited to go back and look at?
James: Oh, yes, particularly the mountain butterflies’ adaptations to surviving particularly harsh winters.
EarthFix: If someone’s out hiking, where do they look for caterpillars? How do they find them?
James: Caterpillars tend to hide, but then again there are some that just sit out on leaves because they’re protected by chemicals, or as I mentioned before the California Sister, by aggression.
Some can live in nests. For example, there’s some common butterflies that feed as caterpillars on stinging nettles. If you want to attract butterflies to your garden, you should set aside a little patch in the garden for stinging nettles. I know it’s not everybody’s favorite plant, but it’s the favorite plant of at least five very attractive butterfly species.
So when you’re out hiking, if you’re just observant, you will see caterpillars just sitting on leaves, often on the underside of leaves if you look up, you’ll see them silhouetted.
EarthFix: Did you have a favorite photograph that when the shutter clicked, you said, ‘Yes, I’m so glad I got that.’?
James: There’s countless examples of that. We wouldn’t like to work out exactly how much time and effort we put into this, particularly money. It cost a lot to find a lot of these species and a lot of time.
There was a number of species where it took many years of trying to get hold of the female. Then once you’ve got the female, you don’t always achieve success in getting the eggs laid and for the caterpillars to develop. It was a hit and miss process.
For the 159 species we reared, each one was reared twice, and many were reared three, four, five, six times to get all the stages we needed. On a particularly hard species where it might have taken 10 years to succeed, then actually achieving the pictures was a huge relief.
EarthFix: When you were looking for the species was it kind of like an expedition?
James: I actually turned it into a family expedition. My wife and our two daughters participated heavily in this process over the last 10 years. My 8-year-old daughter was only a baby when we first started this, so her whole life has revolved around this actually. She’s rewarded by having her picture in the book somewhere.
It just amplified the feeling of success and gratitude when we actually succeeded in getting the species we were after.