Wednesday, December 16, 2015

New native beetles by the dozen: Maui the origin of Hawaiian beetle group

You’d think humans have crawled over every inch of the Hawaiian Islands and found everything, but increasingly, if you go looking for insect life in native habitats, you’ll find stuff no one has ever seen before.

A new paper describes an amazing 74 new species of one group of beetles on Haleakala.

(Image: Three of Maui’s beetles look superficially similar, but are from different places and have differences that make each a unique species. A is Mecyclothorax perseveratus from Waikamoi, B is Mecyclothorax perstriatus from Kahakapao and C is Mecyclothorax superstriatus from Polipoli. Credit: Liebherr paper.)

Cornell University entomologist James K. Liebherr described the find in his paper, “The Mecyclothorax beetles (Coleoptera, Carabidae,Moriomorphini) of Haleakala-, Maui: Keystone of a hyperdiverse Hawaiian radiation.” It was published in the journal ZooKeys.

“The Hawaiian Islands are home to a remarkable assemblage of carabid beetles, unique in the World for its composition, as well for its inordinate species-level diversity,” Liebherr wrote.

And despite finding dozens of new species, Liebherr said the work’s not done.

“Looking at present distributional knowledge , we may predict that species or populations may be discovered that represent areas of endemism without any present species records,” he wrote. He suggested, for example, that there might be interesting things to find in the koa forests of Kipahulu.

“Based on information in hand, there are two diversity hotspots for Mecyclothorax beetles on Haleakalā. These include the forests of Waikamoi, and the upper elevations in and surrounding Kīpahulu Valley,” he said.

But while there’s a lot still to find, he also failed to find a number of species that scientists located in the 1800s. There may be a fair amount of extinction going on, Liebherr said.

The first Mecyclothorax beetle probably arrived in what is now Maui County—once a single island that is known as Maui Nui—as much as 1.9 million years ago. Since that time, it has evolved into more than 200 species.

Oahu and the Big Island have only a few species, and they are believed to have radiated from an introduction from Maui Nuii. Kaua`i has no Mecyclothorax at all.

Here's how Science Daily told the story.

© Jan TenBruggencate 2015

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