The influence of temperature on migration of Lepidoptera into Britain

A unique 113-year record of numbers of nine migrating butterflies and 20 migrating moths is examined in relation to temperatures on the migration route, to temperatures in England, and to the North Atlantic oscillation (NAO). This study clearly reveals the strong association between numbers of migrant Lepidoptera and temperatures in France; with higher temperatures associated with increased migrant numbers. The NAO also appears influential with high index years associated with increased numbers. The strong temperature link suggests that Britain and other northern temperate countries can expect to receive larger numbers of migrant Lepidoptera if climate warms as predicted in the 21st century.