During August and September 2020, Tomáš Kadlec and Michal Knapp searched in vain for unknown populations of Chapman’s blue (Polyommatus thersites) in the Bohemian Central Mountains. Unfortunately, it seems that this species is currently even rarer than we thought. On the contrary, the population of the rock grayling (Hipparchia semele) in Prague is doing very well. We were pleasantly surprised with observations of their flights to the housing estates even relatively far from the Prokopské údolí (one of largest nature reserves in Prague). During next year we would like to monitor the Prague population of this species in more detail.