Quantification of Esterases and Phosphatases in Adults of Tribolium castaneum (Herbst) Exposed to Various Plant Extracts

Our previous results showed that plant extracts are a decent source of botanical pesticides with effective control of stored grain insect pests. Keeping in view of these findings, we have further studied the effect of various plant extracts (Melia azedarach, Nicotiana tabacum, Eucalyptus globulus, Azadirachta indica, Datura inoxia and Colosynthus citrullus) at various doses (5.0, 10.0, 15.0 and 20.0% including a control treatment 0.0%) and different time intervals (2, 4, 6, 8 and 10 days) for the quantitative changes in the esterases (acetylcholinesterase, α-carboxylesterase, β-carboxylesterase) and the phosphatases (acid and alkaline phosphatases) in whole body homogenates of adults of Tribolium castaneum. The outcomes revealed that the tested plant extracts of A. indica and N. tabacum had strong insecticidal effect against T. castaneum. The survivor test insects of these experiment used for biochemical analyses reported that activities of esterases and phosphatases decreases with the increase in time interval and concentrations of plant extracts except in case of the plant extracts of D. inoxia and E. globulus, where no statistical alterations were found in acid and alkaline phosphatases. Moreover there was also found a direct relationship between time and concentration for the mortality of adults of T. castaneum against different plant extracts. These results evidenced that plant extracts have decent anti-enzymes activity in T. castaneum to keep its population down.