FIBER DIGESTION IN ARTHROPODS

Fibre digestion in vivo was studied in eight species of arthropods. Th e highest degree of fibre digestion (61-65%) was measured in Schistoce rca gregaria, Eurycanta calcarata, and larvae of Pachnoda marginata. T his approximates the fibre digestion of mammalian hindgut fermenters. The presence of propionic acid, butyric acid, and i-valeric acid, in t he different compartments of the intestinal tract of arthropods appear ed to be a good indicator of microbial fermentation. From the results it becomes clear that different strategies can be followed for the deg radation of fibres. Cellulolytic enzymes can be produced by symbiotic microorganisms. In P. marginata larvae, fibre digestion was the result of this microbial activity. On the other hand, S. gregaria and E. cal carata, which possess low numbers of bacteria in their intestinal trac t, degrade fibres with the aid of endogenously produced enzymes. The o rigin of cellulolytic enzymes did not influence the efficiency of fibr e digestion. (C) 1997 Elsevier Science Inc.