New - And Maybe Last - Butterfly Species Found in U.S.

The extended family of butterflies found in the United States has grown by one --- not because of a new discovery, but because, after about 100 years, experts finally realized they'd found a new species.

The green eyes of the recently-dubbed Vicroy's Ministreak were the long-undetected give-away.

According to Jeffrey Glassberg, President of the North American Butterfly Association, the Vicroy's Ministreak went unrecognized for a century because it looks nearly identical to another butterfly species known as the Gray Ministreak.

Eye color has not traditionally been used as an identifying trait of butterflies and, besides, all the museum samples of preserved Ministreaks had similar dark brown eyes.

In the wild, however, the Vicroy's Ministreak's green eyes stand outset it apart. After deconstructing the insect's genitalia, an important step in the identification process, entomologists confirmed that the butterfly was a new species.

The Vicroy's Ministreak, which lives in the shrub lands of south Texas along with the Grey Ministreak, was named by Glassberg, in honor of his wife, Jane Vicroy Scott. The butterfly's full scientific name is Ministrymon janevicroy.

Zoologists now believe the thumbnail-sized Vicroy's Ministreak may be the last truly distinctive butterfly species discovered in the U.S.

Glassberg, along with Robert Robbins, the butterfly curator at the Smithsonian in Washington, DC, announced the new species in the open access journal Zookeys.

There are approximately 20,000 species of butterflies in the world, according to NABA, with about 725 species sited in the North American continent, north of Mexico.

About 575 butterfly species are spotted regularly in the lower 48 states and 275 species are noted regularly in Canada. An estimated 2000 species are found in Mexico.

An adult butterfly has an average life-span of about one month, though in the wild, most butterflies live short times, thanks to the dangers of predators, disease and contact with large objects, such as speeding automobiles.

Data from NADA says the smallest butterflies generally live only a week or so, while a few butterflies, such as Monarchs, Mourning Cloaks and tropical heliconians, can live up to nine months.