Eine vergleichende Untersuchung über die Plastronstrukturen bei Milben (Acari)

Abstract

Mites which show air (= plastron) retaining cuticular structure can be divided into three groups: Group I with direct formation of grooves on the entire surface of the body; group II with a ventrolateral channel system (= peritrema), wich is covered by hydrophobic trichomes and in connection with the stigmata; group III with a hydrophobic layer of scretory material (= cerotegument) which covers certain parts of the body or the entire body including the stigmata. — The stability of an air retaining cerotegument in the aquatic oribatid mite, Hydrozetes lacustris, is maintained through a pressure range of —98kPa (= 0.022 atm) to + 550kPa (=5.5 atm). The activity of plastron‐bearing oribatid mites which are annually flooded for 6 months in Central Amazonian inundation forests, seems to depend on the concentration of dissolved oxygen in the water. First observations are given for one of these, “semi‐aquatic” species, Rostrozetes foveolatus. Copyright © 1992 Wiley‐VCH