The apparent influence of climatic change on recent changes of range by European insects (Lepidoptera, Orthoptera)

The apparent influence of climatic change on recent changes of range by European insects (Lepidoptera, Orthoptera) For several years I have been collecting data concerning changes in the ranges of European insects, especially Lepidoptera and Orthoptera. The vast majority of those species which have altered their ranges since 1850 have spread to the north, north-west or west (e.g. 96% of the Lepidoptera expanding their ranges). Of the smaller number of species where the range has contracted, the majority (e.g. 75% of the Lepidoptera) have retreated southwards, south-westwards or south-eastwards. I have attempted to correlate these range changes with the main climatic fluctuations from 1850 to the present. Throughout this long period of predominately warming climate in Europe, those insect species which have been expanding their ranges have done so in steadily increasing numbers, especially since 1975, thus coinciding with the marked increase in temperatures worldwide associated with the anthropogenic greenhouse effect.