Moth lineage provides a key to species diversification

March 28, 2014 by Patrick Schmitz
Moth lineage provides a key to species diversification
Hyposmocoma caterpillar casings.

To many, moths are just the dull relatives of butterflies that often startle us in the dark. But for UH Mānoa Junior Researcher Dr. William Haines, former Junior Researcher Dr. Patrick Schmitz and Professor Daniel Rubinoff, these fascinating creatures provide insights into Hawai'i's ancient, vanished ecosystems. The College of Tropical Agriculture and Human Resources entomologists published their findings in an article, "Ancient diversification of Hyposmocoma moths in Hawaiʻi," in the March 20 edition of the online journal Nature Communications.

The moth genus Hyposmocoma, otherwise known as the Hawaiian fancy case caterpillar for the elaborate silk cases the larvae construct and carry on their backs (see photo), is one of very few lineages that diversified across the entire Hawaiian Archipelago. A single colonist gave rise to more than 400 species, including many restricted to the tiny, remote northwestern atolls and pinnacles, remnants of ancient, extinct volcanoes.

"Searching for those tiny caterpillars hiding in their fancy cases was like a gigantic egg hunt," Schmitz said. "Finding them under bark and leaves, in rock crevasses and streams, was a long-lasting task. And once you get them, you have to feed them. Many of them are very fond of carrots and fish flakes. But others are more sophisticated and prefer rotten wood or fresh meat!"

Through their research, Haines, Schmitz and Rubinoff report that Hyposmocoma has been in Hawai'i for about 15 million years, contrasting with previous studies of the Hawaiian biota that have suggested that the vast majority of lineages colonized the archipelago after the emergence of the current high islands, around 5 million years ago.

The three researchers used a "molecular clock" based on the ages of the different Hawaiian islands and the moths' DNA to reconstruct a "family tree" going back in time. "We found a recurring pattern where the earliest 'splits' in the family tree occurred on the oldest islands," Haines said. "We made the assumption that these splits occurred as new islands were formed and moths dispersed down the archipelago. This made it possible to use the ages of the islands to estimate rates of mutation for various genes. We then extrapolated backwards to figure out when the first Hyposmocoma colonized Hawaiʻi and began evolving into multiple species." They show that Hyposmocoma has dispersed from the remote Northwestern Hawaiian Islands to the current high more than 20 times, something that has never been shown in another Hawaiian animal or plant group.

Island biogeography, or the study of geographic distributions of organisms, is fundamental to understanding colonization, speciation and extinction. Remote volcanic archipelagoes, like Hawai'i, are ideal natural laboratories for studying biogeography because they provide context for how colonization and speciation has occurred in time and space.

"Hyposmocoma, since it still has lots of species, might be our last, best, chance to see how life evolved in the Hawaiian Islands," Rubinoff said. "For most groups, many, if not most of the species are extinct, or there just weren't that many to begin with. But for these moths, we still have enough to paint a picture of how an animal might have arrived in Hawai'i, millions of years ago, and evolved into something diverse and unique."

Explore further: Amphibious caterpillars discovered in Hawaii (w/ Video)

More information: "Ancient diversification of Hyposmocoma moths in Hawaii." William P. Haines, et al. Nature Communications 5, Article number: 3502 DOI: 10.1038/ncomms4502. Received 29 July 2013 Accepted 20 February 2014 Published 20 March 2014

Related Stories

Amphibious caterpillars discovered in Hawaii (w/ Video)

March 23, 2010

Moths of the Hawaiian genus Hyposmocoma are an oddball crowd: One of the species' caterpillars attacks and eats tree snails. Now researchers have described at least a dozen different species that live underwater for several ...

Hawaiian Islands formed through extrusive volcanic activity

September 3, 2013

Scientists generally believe that the Hawaiian Islands formed primarily through endogenous growth, or intrusion, in which hot magma intrudes into a rock and then solidifies before it reaches the surface. However, a new study ...

High genetic diversity in an ancient Hawaiian clone

December 22, 2011

The entire Hawaiian population of the peat moss Sphagnum palustre appears to be a clone that has been in existence for some 50,000 years researchers have discovered. The study is published in New Phytologist.

Recommended for you

Protein disrupts infectious biofilms

December 8, 2016

Many infectious pathogens are difficult to treat because they develop into biofilms, layers of metabolically active but slowly growing bacteria embedded in a protective layer of slime, which are inherently more resistant ...

An anti-CRISPR for gene editing

December 8, 2016

Researchers have discovered a way to program cells to inhibit CRISPR-Cas9 activity. "Anti-CRISPR" proteins had previously been isolated from viruses that infect bacteria, but now University of Toronto and University of Massachusetts ...

The song of silence

December 8, 2016

Like humans learning to speak, juvenile birds learn to sing by mimicking vocalizations of adults of the same species during development. Juvenile birds preferentially learn the song of their own species, even in noisy environments ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.