Otakar Kudrna photographing the Moorland Clouded Yellow (Colias palaeno), from his own webpage (http://www.butterflies.de/Kudrna/kudrna_us.htm).

 
 
  Part of: Balletto E, Leigheb G (2021) Otakar Kudrna 1939–2021. Nota Lepidopterologica 44: 133-140. https://doi.org/10.3897/nl.44.67734