They are called melanic moths.

Quick answer

In biology, an individual with more dark pigment than the usual form of its species is described as melanic , so moths that have more dark spots than the average moth are called melanic.

Extra context

  • The classic example is the peppered moth, where darker, more heavily spotted individuals are referred to as melanic forms.
  • “Melanic” comes from melanin, the dark pigment that makes these moths appear darker than the typical form.

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