ZARIDAH, MZ, NOR AZAH, MA & ROHANI, A. 2006. Mosquitocidal activities of Malaysian plants. Extracts from about 30 species of plants in Malaysia were tested for their ability to kill the larvae or to repel or knock down the adults of Aedes aegypti, the vector mosquito for dengue and dengue hemorrhagic fever. Observation of mortality was made after 24 hours of exposure to the plant extract/essential oil to obtain the median lethal concentration (LC50) of the plant extract/essential oil tested. In repellency and knockdown effects of adult mosquitoes, median effective concentration (EC50) was obtained after each test. The three best extracts for killing larvae were the essential oils of Zanthoxylum acanthopodium stem, Aquilana malaccensis wood and Pelargonium citrosum plant. For repelling adult mosquitoes, the most effective was the leaf essential oil of Cymbopogon nardus, followed by that of A. malaccensis. Knock-down ability was best with mosquito coils made from the seed kernel of Azadirachta indica, followed by the leaf of C. nardus and the wood of Fernandoa adenophylla.