Abstract
Fourth-stadium nymphs of the brown-winged green bug, Plautia stali, were orally labeled with [35S]cysteine. We then measured the levels of radioactivity in the fourth- and last-stadia exuvia. Levels of radioactivity in the exuvia increased with increasing doses of [35S]cysteine. The radioactivity levels of labeled exuvia treated with KOH suggested that the [35S]cysteine was incorporated into cuticular proteins. The degradation pattern of labeled exuvia by bovine pancreas protease and crude enzyme solutions prepared from entomopathogenic fungi suggested that radiolabeled exuvium can be used as a substrate for cuticle-degrading enzymes.
