Toxicity of four botanical insecticides to fingerlings of Nile tilapia and common carp

Abstract

Static bioassay test was done to determine the toxicity of four botanical insecticides (BI) - Blumea balsamifera leaves, Vitex negundo leaces, Azadirachta indica seeds, Tinospora rumphii stems to fingerlings (0.8 - 1.5g) nile tilapia (Oreochromis niloticus) and common carp (Cyprinus carpio). Median lethal concentration (g/1) obtained at 96 - hour of exposure for O. niloticus and C. carpio, respectively, were 1.54 and 137 (B. balsamifera), 4.95 and 3.53 (V. negundo), 1.59 and 0.55 (A.indica), and, 0.77 and 2.13 (T. rumphii).

Analysis on the levels of toxicity of each BI showed that A. indica was the most toxic to O. niloticus to C. carpio, at 24 - h of exposure. At 96 - h, however, B. balsamifera and T. rumphii appeared to be the most toxic to O. niloticus while T. rumphii to C. carpio. V. negundo was the least toxic to both test species. Results of this study could be used as basis for field application rates of the test botanicals as piscicide in ponds and as insecticide in pest management rice-fish farming.