The Sahel-Precipitation as a Main Cause for the Invasions of Death's Head Hawk Moths Acherontia atropos (Linnaeus, 1758) into Central Europe North of the Alps. Death's Head Hawk Moths occurred much more abundant north of the Alps in the 1950ies and 1960ies than from the 1970ies into the 1990ies. Summers in that former period had been cooler, however, than in more recent years. Temperature, therefore, cannot have been the main cause for the northbound migration. But a comparison with the amount of precipitation in the Sahel region south of the Sahara reveals a much better coincidence (cf. fig. 1 ) and provide a proper explanation for the changes in abundance of the Death's Head Hawk Moths across the 20th century.