A new butterfly species from Texas, given the common name Vicroy's Ministreak, was discovered because of its striking olive green eye color, and was given a formal scientific name (Ministrymon janevicroy). This beautiful new butterfly may be the last truly distinctive butterfly species to be discovered in the United States.
Although individuals of Vicroy's Ministreak were deposited in the Smithsonian entomology collections a century ago, this species was unrecognized because it was confused with the common, similar-looking Gray Ministreak. Interestingly what distinguishes the two species is the distinctive olive-green eyes of the new species in contrast to the dark brown/black eyes of the Gray Ministreak.
As their common names suggest both species are diminutive, about the size of a thumbnail, and may occur at the same time and place. Besides eye color, each has different wing patterns and different internal structures. They have different, but overlapping, geographic distributions and habitat requirements.
Jeffrey Glassberg, President of the North American Butterfly Association, discovered Vicroy's Ministreak, and he named the species after his wife (Jane Vicroy Scott). Bob Robbins, the butterfly curator at the Smithsonian in Washington, DC, together with Glassberg, are the authors of the paper officially describing Vicroy's Ministreak, published in the open access scientific journal ZooKeys.
Regardless of whether Vicroy's Ministreak turns out to be the last truly distinctive butterfly to be discovered in the United States, the era of new butterfly species, which began with Linnaeus more than 250 years ago, is ending in the United States. In tropical America, however, there are still hundreds upon hundreds of butterfly species awaiting discovery.
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More information: Robbins RK, Glassberg J (2013) A butterfly with olive green eyes discovered in the United States and the Neotropics (Lepidoptera, Lycaenidae, Eumaeini). ZooKeys 305: 1, doi: 10.3897/zookeys.305.5081