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A Little Bit of Spit and a Whole Lot of Patience: What It Takes to Produce a Butterfly Field Guide

Swallowtail butterflies puddling on the Pipeline Road

Swallowtail butterflies puddling on the Pipeline Road. (Photo credit: Sebastián Mena.)

By Laura Kraft

The Pipeline Road in Panama’s Soberania National Park is world-famous for its birds. In fact, in Netflix’s popular Our Planet documentary, the first episode features the Golden-Collared Manakin’s fabulous dance routine, filmed at the famous Pipeline Road Trail. But one scientist at the Smithsonian Tropical Research Institute (STRI) in Gamboa, Panama, wants to show off another flashy group of organisms at this biodiversity hotspot: its butterflies.

Sebastián Mena grew up in Ecuador, where he first fell in love with entomology while working with a professor at the Pontificia Universdidad Católica in Quito to monitor Ecuadorian butterfly communities. He traveled to Panama to do a research internship with Owen McMillan but found himself itching to pick up a more science-communication-focused project, one he already had plenty of experience in: guidebook writing. Mena already had experience collaborating on a field guide for butterflies in Ecuador, but he says he wanted to take this project farther than he ever had before. He undertook the entire collecting, photographing, and design of this latest guidebook.

Sebastián Mena of the Smithsonian Tropical Research Institute

Sebastián Mena of the Smithsonian Tropical Research Institute (STRI) in Gamboa, Panama, collected and photographed 120 butterfly species for a guidebook he co-authored about the butterflies of Panama’s Pipeline Road Trail. Now he is working on a future project, creating high quality posters about butterflies for use in outreach around the country. (Photo credit: Laura Kraft)

First, Mena collected butterflies. He headed out every day into the rainforest loaded down with a long net, traps, and baits. While butterfly experts that Mena knew in Ecuador favor things like rotting fish, fruit and rum mixtures, and even malt to attract butterflies to bait stations, Mena found that simply using overripe bananas worked best for him.

Running up and down the Pipeline Road daily for months, Mena finally caught 120 species of butterflies for the book, which he estimates may be half of the butterfly richness in the area. Says Mena, “Some species only live in the canopy, and it’s basically impossible to catch them. Others are super fast, and you basically just see a shadow pass and know it was there.”

Once he caught them, Mena carefully tucked live butterflies into wax envelopes to prevent them from damaging their wings and brought them back into the STRI laboratory to be photographed. Mena set up a DSLR with macro lenses, a flash unit, a diffuser, and a white background, then he quickly and carefully photographed his delicate subjects.

Book cover for Butterflies of the Pipeline Road

The Pipeline Road Trail in Panama’s Soberania National Park is world-famous for its birds, but a new guidebook by researchers at the Smithsonian Tropical Research Institute in Gamboa, Panama, showcases 120 species of butterfly found along the trail, which co-author Sebastián Mena says may be only half of the butterfly diversity present there. (Guidebook page republished with permission.)

“Some people put the insects in the freezer for a while to photograph, but I don’t think that’s necessary. The low temperature of the lab already helps. Some species you can set against the background, and they’ll be fine, but other species just don’t want to be there,” says Mena. For those trouble species, Mena would usually have a friend carefully hold the butterflies by their membranous forewing with a pair of specialized tweezers while Mena would carefully focus the camera. When the friend released the butterfly, Mena would have only a second or two to get a shot before the butterfly would get too restless and flighty to photograph.

Anatomy page from Butterflies of the Pipeline Road.

To keep restless butterflies still enough to photograph for a guidebook about Panama’s Pipeline Road Trail, researcher Sebastián Mena says a little bit of spit helped: “If [butterflies] are eating something, they are going to be still. I use some of my saliva and put it on their proboscis, and they’re going to be trying to swallow it and be still for a while.” (Guidebook page republished with permission.)

Mena had another trick up his sleeve for keeping butterflies happy during the photo shoot. “If [butterflies] are eating something, they are going to be still. I use some of my saliva and put it on their proboscis, and they’re going to be trying to swallow it and be still for a while,” says Mena. After photographing his specimens, Mena returned almost all of the butterflies back to the trail, except those that were particularly difficult to identify—these were kept, identified by colleagues, and added to STRI’s collection.

Mena’s field guide includes more than just adult butterflies. He turned to Rémi Mauxion, a French laboratory technician at STRI and expert at rearing Lepidoptera to provide larvae and pupae of some of the butterflies to include in the book.

Brushfoots page from Butterflies of the Pipeline Road.

Due to the somewhat 2-dimensional nature of butterflies, Mena was able to get away with using photo stacking only for some images of larvae and pupae. (Guidebook page republished with permission.)

With thousands of photographs in hand for the guide, Mena labored over designing the book. With help from the communications department at STRI, he taught himself how to use book-publishing software and began to lay out the pages. Some things Mena says he learned the hard way, like when he forgot to add extra space to the parts of the pages close to the book’s binding: “The book has like 200 pages, and I had to fix every one. But that’s how you learn!”

His part now completed, Mena turned the book over to the Smithsonian Institute for publication. They hope to release the book both online and in a physical form to be released at the Gamboa Biodiversity Day in August. (Find more info at or via Instagram @gamboaheliconius.) In the meantime, Mena has returned home to Ecuador to continue working on a series of posters to use for outreach. You can see more of his photography at his Instagram, @mena_sebas.

Laura Kraft is a Ph.D. student at North Carolina State University and a National Science Foundation Graduate Research Fellow. When she isn’t traveling the world, she spends her time making science more accessible through science writing and outreach. Email:

1 Comment »

  1. I would like to know how can I buy the book Butterflies of Pipeline Road. I have a permit from Ministerio de Ambiente to collect butterflies in Panama since three years. I am an assistant researcher (ASSISTANTES). That book will help me to identify a lot of butterflies collected at Pipeline Road in Panama’s Soberania National Park. Thank you very much. I live in Quebec City, Canada.
    Thank you very much.

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