We address changes in butterfly species richness in southern Britain since 1930 by examining the location of 10 km x 10 km butterfly hotspots - centres of species richness - for two consecutive time periods. Hotspots have been lost over time as overall diversity has decline. Particularly heavy losses have been detected in southern counties. The coincidence of butterfly hotspots with those for other taxa suggests that a wider range of organisms may also be suffering similar losses in southern Britain, which is the most species-rich area for many groups. Keywords: butterflies, species richness, hotspot, temporal changes.