The bioactivities of 444 species of insecticidal plants collected from northwestern China were tested with Sitophilus zeamais Mots. in the laboratory. The laboratory tests showed that 64 species of the 444 plant samples had inhibiting effectiveness to the population formation of S. zeamais. Stronger effects were obtained from the samples of the following plants: Artemisia sieversiana, Kochia prostrata, Acer negundo, Humulus scandens, Carpesium cernuum, Ricinus communis, Artemisia intricata, Cuscuta japonica, Atriplex patens, Suaeda corniculata, Sabina vulgaris, Punica granatum, Sorbaria kirilowii, Medicago falcata. Each of the plant samples showed a more than 80% inhibiting efficacy to the test insect population formation. Their contact and fumigant toxicity to the test insect were not observed in our experiments. These plant materials, because of their low cost, local availability, safty to human beings and environment, may be developed and used to prevent grain, seeds and forages in store from insect attack.
Sitophilus zeamais Mots. Botanical insecticides-Screeing studies of insecticidal plants