Oryzacystatins Exhibit Growth-inhibitory and Lethal Effects on Different Species of Bean Insect Pests, Callosobruchus chinensis (Coleoptera) and Riptortus clavatus (Hemiptera).

Oryzacystatins I and II, cysteine proteinase inhibitors in rice seeds, caused growth retardation of different species of bean insect pests, Callosobruchus chinensis (Coleoptera) and Riptortus clavatus (Hemiptera), when added to their diets at concentrations of 0.3-0.5% (w/w). At concentrations of up to 1%, almost all insects died. Our results suggest the usefulness of cystatin for insect pest control and also the critical role of cysteine proteinase in the digestive events of insects.