Mosquito larvicidal activity of trichilia roka chiov. (meliaceae) and hyptis suaveolens poit (Labiatae)

Trichilia roka Chiov. (Meliaceae) and Hyptis suaveolens Poit. (Labiatae) were Collected in an effort to search for new insecticidal agents from plants. Various Plant parts of T.roka were extracted with methanol, while fresh leaves of H.suaveolens were subjected to steam distillation in order to obtain the volatile oil. The extracts and the volatile oil were screened for Iarvicidal activity against larvae of Culex quinquefasciatus and Anopheles gambiae mosquitoes. Extracts from the fruit pericarp and testa of the seed of fro/ca, and the volatile oil from H.suaveolens were found to be active against the larvae of both mosquito species. The LCE,) values against C.guinquefasciatus were 0.87, 4.34 and 10.8 ug/ml for H.suaveolens volatile oil, testa and pericarp extracts of T.roka, respectively. For, 4n.gambiae, the observed LCSO values were 0.30, 6.45 and 3.46 ug/ml, respectively. Extracts from the root, stem bark, leaf and seed kernel of T.roka were inactive in this bioassay system. The Iarvicidal activity of T.roka and H.suaveolens is quite promising. Thus, these plants are worth investigating further to obtain the active constituents