POLYSACCHARIDASES IN ASTIGMATID MITES (ARTHROPODA, ACARI)

Assays for amylolytic, cellulolytic and chitinolytic activity were carried out on 6 spp. of economically important Astigmatid mites, Acarus siro L., Glycyphagus destructor (Schrank), G. domesticus (De Geer), Rhizoglyphus callae Oudemans, R. robini Claparede and Tyrophagus longior (Gervais). Amylase and chitinase were found in all species examined whereas cellulase was detected only in those of Rhizoglyphus and Tyrophagus. No significant differences in specific activity between species were found for amylase, T. longior (Gervais) and Rhizoglyphus spp. showed similar cellulase levels. A. siro L. and Glycyphagus spp. possessed significantly higher levels of chitinase compared to Rhizoglyphus spp. and T. longior (Gervais). No intraspecific differences for any of the 3 enzymes were detected. Trophic specialization is discussed in relation to digestive abilities.