Abstract

Water contamination is a current environmental problem in different parts of the world and a huge variety of pesticides are involved in this process. Butaforce is a major herbicide used in agriculture for the control of grass and other broad leaves while termex is an insecticide used for the control of termites and other insects in homes and agricultural fields. The present study evaluated the toxicity of these two widely used agricultural pesticides, butaforce and termex on Bufo regularis tadpole. The 96h LC50 of butaforce and termex on B. regularis were 0.42mg/L and 1.13mg/L respectively. The safe levels ranged from 4.20×10-2mg/L to 4.20×10 mg/L in butaforce and from 1.13×10-1 to 1.13×10-5 in termex. The results also indicate concentration and duration dependent increase in mortality rates of C. gariepinus exposed to the pesticides. There were significant differences (p<0.05) in LC(10- 90), no observe effect concentration (NOEC) and lowest observed effect concentration (LOEC) for different times of exposures. While the maximum allowable concentration (MAC) of butaforce was 4.2mg/L in B. regularis tadpole the value increased to 11.30mg/L in termex showing that butaforce was more toxic to B. regularis than termex. The preset findings suggest that both pesticides were toxic to B. regularis and should be used with utmost care in our environment.

Keywords: Pesticides; Lethal concentrations; Amphibians; Nigeria