The black form of the peppered moth rapidly took over in industrial parts of the UK during the 1800s, as soot blackened the tree trunks and walls of its habitat. They changed their color due to the industrial revolutions as the trees and and nature had become black due to the soot. They camouflage to protect them from predators and since the Industries had developed they did couldn't blend with the environment.
So with genetic mutations as the Moth's with a black color from other countries had come and slowly the increase in blackmoths had increased.
Hey there, it's me Venom. I hope this is the answer your looking for.