How good of an eye do you have for new species? Besides the obvious eye color difference, what else can you spot that distinguishes the new species (left) Ministrymon janevicroy from the old species Ministrymon azia? If you noticed the pebbly texture and grayer color of the new species, you’d be correct. There are other differences that are a bit harder to see, but enough to officially publish the discovery of the new species in ZooKeys at the end of May.
The common English name for the new species will be Vicroy’s Ministreak, which distinguishes it from the Gray Ministreak butterfly — never mind that the Vicroy Ministreak is grayer than the Gray Ministreak (these things happen).
You will not see the new butterfly in any U.S. state except Texas, as its range is from Texas to Guanacaste Province, Costa Rica and in South America on the islands of Curaçao and Margarita. The Gray Ministreak, on the other hand, might cross your path in other parts of the southern U.S., as well as in Brazil, Paraguay, Argentina, and virtually all lowland areas, whether they be a desert in coastal Peru or a rainforest on the Amazon.
The new Vicroy Miniostreak is a bit more selective. It prefers dry deciduous forests and scrublands. Which suits the Gray Ministreak as well. In fact both species have been found in the same locations.
So how can they be different species if they live side-by-side? The answer is called reproductive isolation. This is similar to when two populations of a single species becomes physically isolated from each other and evolve apart, only sexual isolation means there’s something about they way they reproduce that keeps them from mating, and so they can evolve into new species. This is backed up by the genitalia of the Vicroy Ministreak species, which is significantly different from the Gray Ministreak according to the authors of the paper, Robert K. Robbins of the Smithsonian Institution and Jeffrey Glassberg of the North American Butterfly Association.
As for where the name janevicroy comes from, it’s from Jane Vicroy Scott, the wife of Jeffrey Glassberg, the butterfly’s discoverer. There’s a anniversary gift that is hard to beat.
IMAGE: Vicroy Ministreak, Ministrymon janevicroy (left) and Gray Ministreak, Ministrymon azia. (Robbins & Glassberg / ZooKeys)