New Green-Eyed Butterfly Is Rare American Discovery

This image shows the new butterfly species Vicroy's Ministreak, distinguished by its striking olive green eyes. (Image credit: Jeffrey Glassberg)

A new thumbnail-sized butterfly with olive-green eyes has been discovered in Texas, scientists report this week.

Hundreds of butterfly species likely await discovery in the tropics, but in the United States, identifying a truly distinct butterfly like the one from Texas, now dubbed Vicroy's Ministreak (Ministrymon janevicroy), is rare, scientists say.

Lepidopterists may squabble over what counts as a separate butterfly subspecies, but by now the insects have been quite exhaustively documented in the United States. Of the country's 81 known hairstreak butterfly species, for example, 58 were discovered in the 19th century while just 11 were found in the 20th century.

This image shows the long known Gray Ministreak, confused with the newly discovered Vicroy's Ministreak, despite the obvious eye color difference. (Image credit: Jeffrey Glassberg)

"It's entirely possible that this will be the last species of butterfly described from the United States," said Jeffrey Glassberg, president of the North American Butterfly Association. "It's inarguably a completely different species."

The species looks similar to the Gray Ministreak, but what sets the two apart is the striking eye color of Vicroy's Ministreak. The species had gone under the radar of scientists because in dead butterfly specimens, eye color fades, Glassberg explained.

"Historically people approached butterflies with nets and they killed them," Glassberg told LiveScience. But scientists using non-invasive methods of observation like binoculars were finally able to pick out Vicroy's Ministreak.

Beyond eye color, Vicroy's Ministreak is also different from the dark-eyed Gray Ministreak in its wing patterns and internal structures, according to Glassberg and his colleague Bob Robbins, the butterfly curator at the Smithsonian in Washington. The two species' geographic distributions and habitat requirements are also slightly different, though they overlap.Vicroy's Ministreak can be found in dry forests and scrub from Texas to Costa Rica.

Glassberg named the species after his wife, Jane Vicroy Scott, whose eyes are blue. "It was a birthday present," Glassberg said.

He and Robbins described Vicroy's Ministreak on May 28 in the journal ZooKeys.

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Megan has been writing for Live Science and Space.com since 2012. Her interests range from archaeology to space exploration, and she has a bachelor's degree in English and art history from New York University. Megan spent two years as a reporter on the national desk at NewsCore. She has watched dinosaur auctions, witnessed rocket launches, licked ancient pottery sherds in Cyprus and flown in zero gravity. Follow her on Twitter and Google+.