'Nigrita' or melanistic Dione Ratsnakes have been known in the wild for many years, captive specimens where collected in the area surrounding Mostok in North Caucasus.

First bred by Tula Exotorium in 2004. They are generally thought to be a little more difficult to breed than any of the other locality Diones. Males in the past have shown indifference to breeding trials, and often suffered from digestion problems. A new strain was brought into the hobby in 2009 which do not have any of the problems associated with the original line (my pair are from the new strain)

There is some variation in the nigrita morph, some being completely black, whereas other specimens may have white or grey lateral stripes.