After carbonaria: melanic moth frequencies in the Rothamsted Insect Survey

Melanic frequencies in three species of moths during the 21st century are examined using data collected by the Rothamsted Insect Survey for the purpose of monitoring insect distribution and abundance. The classical industrial melanic morph carbonaria in the moth Biston betularia (L.) is no longer present in the samples. Melanic forms in two other species, Odontoptera bidentata (Clerck) and Apocheima pilosaria (Denis & Schifferműller), and the insularia form of B. betularia, all sometimes referred to as industrial melanics, continue to be found and are widely distributed in Britain. Views on why that should be so are discussed.