Crypsis is the ability of an organism to avoid observation or detection by other organisms, either by predation strategy or antipredator adaptation. Many animals have evolved to visually resemble their surroundings by changing their colour. These changes can be experimentally provoked by altering physical parameters (such as humidity) during the development of the nymphs, and also depend on the type of food they consume. This report illustrates coloration changes of the Green Shield Bug (Palomena prasina) during autumn, on specimens caught at the nearby town of Vlašim (Central Bohemia). We recorded the shortest time for the imagos to change color (from bright green to uniform brown) as nine days in an experimental insecta - rium. The rate of color change was influenced by air temperature. The brown colour is evidently an indicator of the diapause. and Lubomír Hanel, Jana Hanelová.