Toxicity of Two Selected Plant Extracts on Termites, Macrotermes Spp. (Isoptera: Termitidae)

Laboratory studies were conducted in the main station of the Nigerian Institute for Oil Palm Research to determine the toxicity of two selected plant extracts (Jatropha. curcas and Ricinus. communis) on adult soldier termites, (Macrotermes spp). The seed of J. curcas and R. communis were extracted using crude aqueous extraction and applied separately at three concentration levels of 10, 20, and 35% (w/v) each on adult soldier termites. Water (2ml) served as negative control while Cypermethrin (1%) served as positive control. The treatment was replicated four times and mortality of adult soldier termites of Macrotermes spp. was recorded at 12 and 24 hours intervals. Phytochemical analysis of the plant extracts was carried out showing the presence of tannins, alkaloids, flavonoids, saponins and phenol. The result showed 100% mortality of Macrotermes spp. on exposure to 1% Cypermethrin and 35% of J. curcas seed extract at 12hrs while exposure to 10% and 20% of J.curcas at 24hrs recorded 100% with water having 0.00% at both 12hrs and 24hrs. There was significant difference between the treatments and the control at 12 hrs. and 24 hrs. (P=0.00). The result also showed that the percentage mortality of Macrotermes spp. (100%) was recorded higher on exposure to Cypermethrin followed by 35% of R. communis seed extract (97.5%) but lowest in the water control (0.00%) at 12 hrs. Also exposure to 10% and 20% extracts of R. communis at 24hrs showed 100% mortality of Macrotermes spp. However, the effect of R. communis seed extract on the adult mortality of Macrotermes spp was significantly different between the treatments and the control at 12 hrs and 24 hrs (P=0.00). The log-probit regression analysis showed that the LC50 of J. curcas and R. communi seed extract after 12 hrs was found to be 9.568% and 8.451% respectively. The study showed that J. curcas and R. communi seed extract have the ability to control adult termites of Macrotermes spp. and can serve as bio-control agents.