Modifications ultrastructurales des parois végétales dans le tube digestif d'une larve xylophage Oryctes nasicornis (Coleoptera, Scarabaeidae): rôle des bactéries

The ultrastructural modifications of plant cell walls have been studied in the food and gut contents from the xylophagous larvae of Oryctes nasicornis. Before ingestion the natural food undergoes a large amount of degradation by fungus-rich microflora of the soil. The break-down of α-cellulose, and amorphous and crystalline cellulose of the secondary walls occurs in the mesenteron and later in the proctodeal dilation where it is greatest. The role of bacteria is recognised and the successive stages of degradation are characterised.