D. leucomelas are a lowland species found at elevations from sea level to over 2600 ft (around 800 meters), and range primarily from western Venezuela to the Guyanas, with remnant populations in eastern/southeastern Columbia and northern Brazil.
D. leucomelas are found in humid rain forest on the ground among the leaf litter as well as in the trees. They can also be found in seasonally drier habitats hidden in damp, shaded areas that protect them from desiccation. They will emerge and congregate after it rains.
“Leucs” are medium sized Dendrobatids, generally reaching about 1 ½” in length (males being slightly smaller). Their color ranges from bright yellow to yellow-orange with broad, irregular black bands which encircle the neck and body, giving them a “bumble bee” appearance – thus the common name. Additionally, there are irregular black spots between these bands as well as on the limbs. Underneath, these frogs are solid black. Certain Guyanan populations have little or no black spotting, and have more uniform bands like their cousins Oophaga lehmani. These ‘Banded’ leucs are also larger than the nominant morph, reaching 1 ¾ – 2” in length. There is also a striking form from the Cerro Autana tepuis in Venezuela that has blue feet. Leucomelas exhibiting traits such as fine spotting, or brown marking rather than black (the “chocolate leucs”) are naturally occurring variations of the nominant form that have been isolated and line bred for the consistency and intensity of those traits.
British Guyana ‘Banded’
D. leucomelas extract and sequester pumiliotoxins from various insects that make up their diet in their natural habitat. There are several members of the Dendrobates genus (i.e., D. auratus and D. tinctorius azureus), as well as the members of the genus Adelphobates that convert these toxins, specifically pumiliotoxin 251D, to the 5x more potent allopumiliotoxin 267A. Less than a milligram of this toxin is lethal for humans, and the skin of a wild leucomelas will contain about ¾ of a milligram of it. By comparison, a wild D. auratus will have about ½ of a milligram , and D. tinctorius azureus can range between ½ and ¾ of a milligram, thus making D. leucomelas leucomelas the most toxic member of its genus.
D. leucomelas are abundant in the areas where they still exist. Tremendous success with captive breeding has greatly reduced the demand for smuggled animals.
 Daly, J.W.; Garraffo, H. M.; Spande, T. F.Clark, V.C.;Ma, J.; Ziffer, H.; Clover, J.F.; Evidence for an Enantioselective Pumiliotoxin 7-hydroxylase in Dendrobatid Poisn Dart Frogs of the Genus Dendrobates. Proc. Natl. Acad. Sci. 2003, 100, 11092-11097 / Richard Auler; Alkaloids of the Poison Dart Frog; The Occurrence, Bioactivity, and Synthesisi of Pumiliotoxins.