Alimentary studies on the Collembolan Paratullbergia callipygos using transmission electron microscopy
Résumé
The food diet of the endogeous Collembolan Paratullbergia callipygos was studied in an oak stand on an acid mull humus. Transmission electron microscopy was used, in parallel with light microscopy, in order to ascertain the effect of soil-dwelling Collembola upon plant materials and some other food substrates. Plant cell walls proved to be severely damaged when passing through the midgut after they have been broken up by mandibles, unless they were protected by coatings of tannins. Laboratory experiments with known substrates, both natural (dead leaves, dead and living roots) or artificial (pure cellulose fibres, starch, etc.) showed that this species was able to degrade cellulose, the process varying according to the type of cellulose. Degradation of other substrates, such as starch, tannins, fungal cytoplasm and chitin also occurred. The possible role of soil Collembola, especially the Tullbergiinae subfamily, in the fast turn-over of fine roots, was discussed.
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