Drosophila are hosts to the first described parasitoid wasp of adult flies Nature Rare Forms of Melanoma and Melanocytic Tumors IntechOpen Histopathological Findings of a Melanocytic Nevus A melanocytic nevus is a benign proliferation of melanocytes. Under the microscope, typical features include: Nests or clusters of uniform melanocytes located at the dermoepidermal junction, Innate Immunity in Insects: The Lights and Shadows of Phenoloxidase System Activation