The melanic allele is dominant to the non-melanic allele. Exposure to UV-B radiation induces the accumulation of usnic acid and melanic compounds. "Emydocephalus annulatus" is more likely to be melanic. Melanic forms have not been found in Japan. Occasionally, much darker (melanic) forms occur. Melanic forms can be found on the European continent. It is less commonly known as melanic acid, the name chosen by William Prout. There are several melanic and non-melanic morphs of the peppered moth. L determines whether a given individual has melanic scales over their forewing band. In the Netherlands, melanic "A. bipunctata" had a distinct mating advantage over the non-melanic form. Melanic forms (e.g. "rebeli") sometimes occur. Males have either xanthic (yellow) or melanic (black) abdominal coloring. In North America, the melanic black morph is morpha swettaria. The colour morphs are the xanthic orange-winged form and the melanic black winged form. Melanic forms of jaguar are common in certain parts of South America.