On the Hawaiian Islands, where isolated, vulnerable pieces of land are surrounded by thousands of miles of ocean, habitat destruction is something of a catchphrase.
It is well known how the arrival of humans about 1,000 years ago drastically changed the ecosystem with the introduction of invasive plants and animals. It has led to stricter policies for releasing non-native pets, increased regulations at trade ports and the emergence of restoration ecology, in which scientists strive to re-create a more native environment.
But within areas seemingly overcome by invasive plants and animals, one Florida Museum of Natural History lepidopterist discovered three new native moth species.
“The mountains in Hawaii look really beautiful, but most of the plants in the lowlands are not supposed to be there,” said Akito Kawahara, assistant curator of Lepidoptera at the Florida Museum, who led a study published in the February 2012 edition of ZooKeys. “If you think about that, it’s really shocking to find some rare, endemic species in an area where these are not typically supposed to be found.”
Kawahara described new species of an unusual genus commonly known as fancy case caterpillars. Similar to how snails carry a shell, the caterpillars wear different ornate “cases” throughout the larval stage of development.
“They move around carrying their home,” Kawahara said. “They are called fancy case caterpillars because they make very extravagant, beautiful cases that are ornamented with sand, branches, lichen or colorful insect parts. Sometimes these cases resemble cigars, burritos, candy wrappers or purses. Others simply look like the tree bark that they rest on.”
Using molecular and morphological data, Kawahara and co-author Daniel Rubinoff of the University of Hawaii named three new species that produce tubular purse cases: Hyposmocoma ipohapuu from the Big Island, Hyposmocoma makawao from Makawao Forest Reserve in Maui and Hyposmocoma tantala from Mount Tantalus, Oahu. The genus Hyposmocoma includes about 350 described species and represents about 40 percent of all the moths and butterflies on the Hawaiian Islands.
“There’s an extraordinary diversity of these moths in Hawaii and the total number may be well over 1,000 species,” Kawahara said. “They’re only found in Hawaii and they’re very threatened. We initially thought purse cases may only include 10 species or so, but there are clearly a lot more. Some species are dual entry, so the larva can peek out of one end of their case and then peek out of the other.”
Hyposmocoma is also unique because many species within the genus are aquatic or carnivorous, which is uncommon in Lepidoptera. Aquatic species may be used as a means for assessing environmental habitat quality, such as the amount of pollution in streams.
Scientists believe Hyposmocoma reached the Pacific islands millions of years ago, long before the colonization of humans. On an island chain where diverse songbirds, flightless rails and rare endemic plants once thrived, it is increasingly valuable for researchers to protect any remaining native biodiversity.
“It’s really important to focus conservation efforts in areas that are pristine and also to restore habitats that are disturbed,” Kawahara said.
By Danielle Torrent | More articles by Danielle Torrent
• Learn more about the McGuire Center for Lepidoptera & Biodiversity at the Florida Museum.