Bioactivities of Extracts from Bamboo against Sitophilus zeamais Motsch.

The extracts of P. platyglossa and B. densiflorum showed fairly good repellencies to adult Sitophilus zeamais Motsch., the repellence class of which attached class Ⅳ at a concentration of 10 g/L, the average rate of repellencies were 77.44% and 64.84% (72h), respectively. The extract of P. platyglossa by Soxhlet method showed stronger repellence than extract obtained by Intermittent-Shaking. Their repellence median concentrations were 0.9994 g/L and 1.8905 g/L, respectively, the regressive equations were Y=0.7346X+4.265(r=0.9938) and Y=0.6819X+4.1295(r=0.9993). At a concentration of 10 g/L, the extract of bamboo exhibited unremarkable fecundity inhibitory effect against Sitophilus zeamais M.. Only the inhibiting efficacy of extract from Brachystachyum albostriatum was above 50%. The result showed significant pofenfial to exploit the environment friendly pesticide and to utilize the resources of bamboo.