Feeding biology of oribatid mites : a minireview

Abstract

The aim of this review is to summarize the existing knowledge on the feeding biology of oribatid mites. Understanding their feeding habits may help in solving the problem of the large number of animal species that co-exist in soil, and it may contribute to a better understanding of the functioning of oribatid mites in the decomposer subsystem. It could be shown (1) that oribatid mites prefer dark pigmented fungi (Dematiacea) over most other soil fungi, (2) that some Dematiacea (Alternaria alternata, Ulocladium sp.) were preferrentially ingested compared to others, (3) that some ectomycorrhizal fungi are accepted as food substrates (Hymenoscyphus ericae, Boletus badius) whereas others are rejected (Amanita muscaria, Paxillus involutus). Stable isotope studies (15N) indicate that oribatid mites form a gradient from phytophagous species over primary and secondary decomposers to predators and scavengers. Molecular methods appear to be a promising tool to study the gut content of oribatid mites in the future. Overall, findings of this review indicate that there is niche differentiation concerning oribatid mite feeding habits but that the feeding preferences of oribatid mites are rather small and therefore are insufficient to explain the high diversity of oribatid mites in soil. We conclude that oribatid mites are generalists with a certain degree of specialization concerning their food resources.