Abstract
The reed beetle species Macroplea appendiculata (Donaciinae) is unique because of its almost completely underwater life. For respiration it uses a plastron – a compact array of rigid, stable, tiny microhairs on parts of the body surface of aquatic insects, where air is kept in a thin layer of hydrofuge hair-piles.
Because of this specific process of respiration, M. appendiculata does not need to emerge from its aquatic environment, even to reach the water surface. The scanning electron microscope has allowed a closer look at the details of plastron structures in three genera of reed beetles (Donacia, Macroplea and Plateumaris).
In the Red List of Threatened Species in the Czech Republic (Invertebrates) the species Macroplea appendiculata is classed as critically endangered and should be protected. In the Czech Republic it occurs only in a few valuable and botanically rich ponds.