DISTINCTIVE CUTICULAR HYDROCARBON PROFILES IN ORIBATID MITES (ACARI: ORIBATIDA)

Cuticular hydrocarbon profiles of representatives of different groups of oribatid mites (Mixonomata: Steganacarus carinatus, Collohmannia gigantea; Desmonomata: Hermannia gibba; Brachypylida: Zetorchestes falzonii) were investigated by gas chromatography - mass spectrometry. In general, cuticular extracts showed a series of straight chain alkanes being arranged in two (or three, respectively) distinctly different patterns: 1) a pattern with a gaussian quantitative distribution of alkanes from C-23 to C-36 was noticed in extracts of C. gigantea and H. gibba, with C-29 - C-32 being most abundant. 2) A pattern exhibiting a saw-tooth-like quantitative distribution of alkanes - with only odd-numberd alkanes being abundant - appeared to be characteristic for S. carinatus. 3) Extracts of Z. falzonii showed no hydrocarbons. The hydrocarbons are considered to origin in a lipid layer which is covering the cuticle: this layer is regarded to represent the inner - and in some cases the only - layer of the oribatid cerotegument. The differences in cuticular hydrocarbon profiles among oribatid species may represent a promising point of attachment for further chemosystematic studies.