Study reveals evolutionary history of hawkmoths’ sonar jamming defense

May 13th, 2015
hawkmoth

A new study shows hawkmoths, including this species belonging to the subtribe choerocampine, produces ultrasound as a defense mechanism against bats.
Florida Museum of Natural History photo by Pablo Padron

By Stephenie Livingston

In the 65-million-year-old arms race between bats and moths, some moth species rub their genitals to jam the calls of bats. Radar jamming is commonly used in human warfare, allowing pilots to render themselves invisible. By unraveling the evolution of hawkmoths’ similar defense, authors of the May 2015 study appearing in the Proceedings of the National Academy of Sciences aim to better understand nocturnal biodiversity and improve human uses of sonar.

Researchers with the Florida Museum of Natural History and Boise State University tracked sonar jamming throughout the evolutionary history of hawkmoths and found that one of the insect world’s most sophisticated defense mechanisms is more widespread than originally thought, existing for millennia.

Until now, the function and evolution of sonar jamming remained largely a mystery, said lead author Akito Kawahara, assistant curator of Lepidoptera at the Florida Museum on the University of Florida campus.

“Before now people thought ultrasound usage in insects was very restricted to certain groups, but it looks much more complex than that,” Kawahara said.

Kawahara and collaborators scoured jungles and forests from Borneo to the Amazon observing hawkmoths. They collected specimens at 70 sites in 32 countries and conducted field-based echolocation experiments and (more…)

Bella moth keeps potentially dangerous invasive plant at bay in Florida

April 14th, 2015
Bella moth

The bella moth, pictured on the flower of an exotic Crotalaria retusa, is changing the plant’s ecology as it feeds on the seeds of this invasive plant.
Florida Museum of Natural History photo by Andrei Sourakov

By Stephenie Livingston

Taming a wild plant may not sound too ominous, unless you are a tiny moth and the plant is 8 feet tall and poisonous.

Lepidopterist Andrei Sourakov with the Florida Museum of Natural History has been studying ornate bella moths, Utetheisa ornatrix, since 2010. His March 2015 study appearing in the Journal of Natural History reveals that the moth is changing its ecology, co-evolving as it adjusts to feeding on the seeds of several invasive exotic plant species.

“Once a species is introduced, they may take on a life of their own,” said Sourakov, collections coordinator at the museum’s McGuire Center for Lepidoptera and Biodiversity on the University of Florida campus. “Eradicating a foreign species that has established is very difficult if not impossible.”

With his trademark spectacles and safari hat, David Fairchild, known as the Indiana Jones of botany, traveled the world during the early 1900s in search of plants and collected thousands of exotics and new varieties, like pistachios, mangos, dates, cotton and wheat, and introduced them to the United States. Fairchild’s writings suggest a variety of exotic rattlebox plants in the genus Crotalaria were introduced to South Florida about 100 years ago. Among them is Crotalaria spectabilis, showy rattlebox, which particularly stands out with its 6- to 8 feet-tall plants and (more…)

Fossils link Caribbean bat extinction to humans, not climate change

February 11th, 2015
Soto-Centeno with bat skull

Study co-author J. Angel Soto-Centeno displays the fossilized skull of a Cuban fruit bat, Brachyphylla nana.
Photo courtesy of J. Angel Soto-Centeno

By Stephenie Livingston

Sharing caves with millions of bats, the Caribbean’s first humans may have driven some species of the winged mammals to extinction.

“Scientists have been studying bat fossils in the Caribbean for years,” said David Steadman, curator of ornithology at the Florida Museum of Natural History. “The problem is, no one knew how old the fossils they were studying actually were.”

Bats have dominated the Caribbean for millennia, once sharing the islands with at least 73 species of mammals, such as primates, rodents and sloths. But following an ancient event called the Last Glacial Maximum, sea levels rose enormously, islands became smaller, and it is thought that most of the Caribbean’s land mammals became extinct.

New radiocarbon dates show that bats continued to thrive until (more…)

Island isolation, warming climate shapes Mediterranean Basin evolution

January 14th, 2015
Mediterranean Basin

Taken on the island of Crete, this photograph shows the typical habitat of bellflowers.
Florida Museum of Natural History photo by Andrew Crowl

By Stephenie Livingston

From the jungles of Southeast Asia to the Greek Islands, Florida Museum of Natural History botanist Nico Cellinese has searched for the answers to how evolution works. But during fieldwork in the Mediterranean Basin—a biodiversity hotspot—she found more questions than answers.

“There are so many islands and so many island endemic species in the basin that it makes you wonder what is going on in this place to make it so highly dynamic,” said Cellinese, associate curator of the Florida Museum Herbarium and Informatics. “It’s a very peculiar place. It’s the kind of place you just have to dive into, and not stop until you figure something out.”

Cellinese received a National Science Foundation $865,000 Early Faculty Development Career Program Award in 2010 to investigate the basin’s rich biodiversity and better understand why certain species only occur there. The grant has supported Cellinese’s research on genetic diversity in the flowering plant group Campanulaceae, also known as the bellflower family—a model group for studying the influences of geological activity, climate change and human pressure on island evolution and endemism.

The five-year award has resulted in the study of nearly 1,000 species of bellflowers worldwide, focusing on those restricted to islands in the Mediterranean Basin. The research adds to the work of Charles Darwin and (more…)

Study reveals 180 million years of parasitic infestation in crustaceans

October 8th, 2014
modern isopod-infested decapods

These modern isopod-infested decapods from the Philippines show prominent swellings caused by parasites on the right side.
Photo courtesy of Klompmaker et al. (2014) in PLOS ONE

By Stephenie Livingston

When Darwin suggested the “survival of the fittest” concept, he did not necessarily mean “survival of the biggest.”

The large marine animals of the past, like prehistoric mega-sharks and whales, draw popular attention and the interest of researchers alike. However, the smaller invertebrate animals dominated Earth in the past and still do today.

Florida Museum of Natural History post-doctoral researcher Adiel Klompmaker’s passion lies in studying the small creatures of the deep. It was while collecting specimens of crustaceans at a fossil reef in northern Spain that he noticed a strange swelling on a fossilized crab.

“What is this? Was it sick? Is this a disease of some kind?” wondered Klompmaker. “I had never observed these swellings in the field.”

The culprit was a parasitic isopod crustacean no more than 16 millimeters in size.

The parasitic isopod causes a swelling (Kanthyloma crusta) so noticeable that it survives in the fossil record, though the traces of these “passengers” have not been thoroughly explored until now, Klompmaker said. The isopod parasites latch onto the inner shell of a crustacean, feeding on it and (more…)

Museum researchers advance ‘DNA revolution,’ tell butterflies’ evolutionary history

September 11th, 2014
Kawahara

Assistant curator of Lepidoptera Akito Kawahara led a yearlong study that revealed monumental discoveries about the evolutionary history of butterflies and moths.
Florida Museum of Natural History photo by Kristen Grace

By Stephenie Livingston

The wispy, delicate nature of butterflies and moths is part of their charm, but their soft bodies do not preserve well in the fossil record, posing a problem for scientists since the early history of Lepidoptera research. Now, by tracing nearly 3,000 genes to the earliest common ancestor of butterflies and moths, Florida Museum of Natural History scientists have created an extensive “Tree of Lepidoptera” in the first study to use large-scale, next-generation DNA sequencing.

Among the study’s more surprising findings: Butterflies are more closely related to small moths than to large ones, which completely changes scientists’ understanding of how butterflies evolved. The study also found that some insects once classified as moths are actually butterflies, increasing the number of butterfly species.

“This project advances biodiversity research by providing an evolutionary foundation for a very diverse group of insects, with nearly 160,000 described species,” said Akito Kawahara, lead author and (more…)

Scientists rewrite evolutionary history of tiny sea cucumbers

July 14th, 2014
Phyrella mookiei

This close-up of the holotype specimen of Phyrella mookiei shows the arrangement of the tentacles and mouth.
Florida Museum of Natural History photo by François Michonneau

By Stephenie Livingston

Scientists at the Florida Museum of Natural History have discovered that a group of tiny sea cucumbers has enormous taxonomic problems.

The use of DNA analyses in taxonomic research has increased in recent years, making it possible for scientists to better understand poorly known species and build knowledge of Earth’s more obscure biodiversity. This type of work is exemplified by the research of François Michonneau, a former invertebrate zoology Ph.D. student with the Florida Museum, who studies the oceans’ most diverse order of sea cucumbers, Dendrochirotida, which includes many small species—most only a few centimeters in length. Studying Phyrella, a genus of Dendrochirotida, Michonneau found that several species of sea cucumbers may be assigned inaccurately within the order.

“The systematics of sea cucumbers is messy and full of inaccuracies,” Michonneau said. “Our revision is just touching the tip of the iceberg as far as cleaning up the confused state of taxonomy in the order Dendrochirotida. The purpose of our study is to identify the appropriate traits to classify sea cucumbers at the genus and (more…)