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Building a Bug's Life Meet the entomologist traversing the tropics to understand insect histories

By Darcy Herlihy/UF News

Somewhere in the middle of the South Pacific, the search is on for a rare butterfly.

Armed with an oversized net and a machete, Emmanuel Toussaint has just two weeks in February to locate the species from deep within the Marquesas Islands of French Polynesia.

If he finds it, it will be only the third reported sighting in history.

The Marquesan snout butterfly, Libythea collenettei, is the sole endemic butterfly known to exist on the islands. Only five samples have ever been collected.

Toussaint, a post-doctoral researcher at the University of Florida's Florida Museum of Natural History, is no stranger to scouting in the oppressive humidity and busy terrain of an island environment. As an entomologist primarily researching water beetles and butterflies, he works to build comprehensive phylogenies, trees that depict relationships between species. And when possible he prefers to collect the samples himself.

Above, Toussaint in Suriname with an electric eel found while collecting water beetle samples. Below, examples of phylogenies Toussaint has worked on putting together.

His work characterizing biodiversity helps us understand how insects have adapted and are adapting to habitats that are rapidly changing and disappearing, due to factors like deforestation and climate change. A better understanding of the way biodiversity is formed can help us adopt appropriate conservation policies. What scientists learn from these trees speaks volumes about why and how to protect Earth’s future ecosystems, Toussaint said. It is the reason why it’s so important to go into the field and see how the animals are coping with disrupted ecosystems.

“Diversity as we know it is a super tiny piece of what’s out there,” Toussaint said. “We are just starting to learn how completely underestimated biodiversity is. Especially with insects.”

But if biodiversity is so vast, why water beetles? Why butterflies?

While many species can give us similar types of information about biodiversity, he said, water beetles are becoming a new model to study evolution. Finding a species of water beetle that falls into the same tree as a terrestrial beetle or discovering that a group of native South American beetles is part of a larger group restricted to Southeast Asia, forces us to ask where and when the shift happened and why.

The answers to those questions lie in places like the middle of valleys and the bottom of waterfalls in tropical climates around the world.

Toussaint's team collecting water beetles from a waterfall in Java, Indonesia

As for butterflies?

Mimicry, rare cases of nocturnal lifestyle, flight evolution and other biological wonders are just some of the reasons why butterflies are a valuable subject for research. Their intimate relationship with flowering plants makes them an ideal model for studying evolutionary biology. And butterflies, with their bright colors and dainty physique, are a model in more ways than one.

“To be honest, well, butterflies, the public loves them,” Toussaint said. When it comes to outreach and education about evolutionary discoveries, this becomes quite the advantage.

Toussaint, Akito Kawahara of the Kawahara Lab, and Dylan Gomes, a student from Boise State, collecting samples in French Guiana.

For example, the project to search for the Marquesan snout butterfly and give a recommendation to the International Union for the Conservation of Nature Red List of Threatened Species, earned Toussaint and a partner a grant to fly to the Marquesas and hunt for new samples.

Off in the mossy green peaks of French Polynesia, Toussaint looks for the host plant where female Marquesan snout butterflies lay their eggs. Although the plant is reportedly still found on all the islands, he only saw it in two places: Hiva Oa and Ua Pou.

Last location where the Marquesan snout butterfly was seen in 2001 in Ua Pou, Marquesas

“In these tiny islands, the habitat can be pretty degraded,” he said. “Plantations, cocoa, bananas, tourism — the natural habitat is scarce.”

Problems like this are not limited to tourist destinations, he said, and the hours of traveling to research locations often take them through damaged rainforests and other once hidden parts of the world being uncovered and used for natural resources.

No two expeditions are the same. From large teaching excursions to solo journeys, adventures inside of extinct volcanoes to dangerous snake encounters in the tropics, Toussaint said there is only one constant factor through each fieldwork trip.

“As soon as we leave the lab to start fieldwork, it’s just like being kids again,” he said. “You get out of the plane in this new place you’ve never been before and it’s just people walking around discovering things like, oh, what is this snake, this butterfly, this plant.”

Toussaint on a trail in Tasmania looking for water beetles

The thrill of the hunt for these insects began back in his youth, Toussaint said, traversing the French countryside with his grandfather, a biology teacher who often took his grandsons out exploring. Once a year, just for fun, he gears up to head to the French Alps to hunt for a unique and hard to find critter: a furry, black and yellow, rove beetle that lives near cow dung.

“I have a very special relationship with this beetle in that every year I try to find it and I usually don’t,” he said. “It’s very cool looking — when it’s not covered in dung.”

Known as the Maid of Kent, this beetle, Emus hirtus, has always been a particular favorite of Toussaint as it is featured on the cover of the first beetle book he ever received, a gift from his grandfather that helped spawn his interest in entomology.

From that interest grew a career path, but it wasn’t until he began higher education that Toussaint truly found his passion for fieldwork as a student in Germany under his mentor, Michael Balke.

Toussaint and Balke searching for a rare water beetle in Alabama.

“He’s the guy who made me the scientist I am, for sure,” Toussaint said.

For Toussaint’s first ever trip into the field, Balke took him on a six-week group expedition to Sumatra, Java and Bali. Balke stayed for two of the weeks, and then left.

“I was alone, and it was like, well, now’s the time, I told myself,” Toussaint said. “You have to teach entomology to students and you are yourself a student.”

From then on, he was hooked on the idea of learning and teaching through active participation. Fieldwork taught him more about the species he was searching for than books ever could.

“I know students who have no clue what the creature they are studying looks like, where it lives, what it does. It’s pretty shocking,” he said. “Students need to have the opportunities to go into the field more and do the hands-on work. You need to be connected to what you’re studying.”

Fast forward to the Marquesas Islands, where Toussaint spends the final week of this venture alone in the field, scouring the land for the faint flutter of butterfly wings.

Two weeks later, the expedition has turned up no results. Toussaint heads home, with no sightings to report and recommends the species be put on the endangered list. But all hope is not lost.

“Some butterflies are pretty hard to find,” Toussaint said. “We’re going back next year in August to look again. It might still be out there.”

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All photos courtesy of Emmanuel Toussaint

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