Toxic Effects Of Three Different Formulations Bifenthrin Against The Workers Of Reticulitermes Speratus Kollbe And Coptotermes Formosanus Shiraki

Termite is a worldwide pest, its harm area accounts for 50% of global total area. Since the signing of the Stockholm Convention, the Chlordane and Mirex which has occupied a dominant position in the field of termite control agents drop out the stage of the history gradually. To look for the new substitute agent becomes the first task of the termite control workers. At present, although the physical control and the biological control are good for the environment, yet they can not be applied widely because of the immature technique and the expensive price. The chemical control is still the main method for the termite control in China or even in the world. With the people's knowledge of protecting the environment and the waste of the resource as well as the concern to the drug residues in agricultural products, the insecticide is undertaking an immense change. The enviromental protection formulations such as SC and EW become the new development direction of the termite control agents. It has not related report for the moment whether the prevention and control effect of the formulation(SC,EW) is different from that of EC.The bifenthrin is the medium toxicity insecticide which is safe to the environment. It does not move in the soil and not accumulated in the human body and the mammals. It has a unique role in both approach-avoidance and high-poisoned, achieving a good prevention and control effect in the new-constructed buildings. This topic is to investigate whether there is difference of the prevention and control effect to the two species between the bifenthrin EC, EW and SC. Make the Reticulitermes speratus and Coptotermes formosanus workers exposed the filter papers, the wood and the 5cm length soil treated with bifenthrin to provide the theoretical evidence for the field application of the bifenthrin EW and SC in the termite prevention and control. The results show that:(1) The experiment of the termite contacting continuously the filter paper with bifenthrin indicates that there is significant difference between bifenthrin SC and EC of the mortality to R. speratus.there is no difference between EW and EC. Reticulitermes speratus wokers are all dead after 48h contacting. The three agents have no significant difference when contacting Coptotermes formosanus workers which are all dead after 72h. The death rate is being related to the concentration and the length of time that termite contacting the filter papers. The bifenthrin has the contacting toxiciy to the two termite species. Reticulitermes speratus has higher contact sensitivity than Coptotermes formosanus. (2) The experiment that bifenthrin preventing the termite to eat the wood indicates that the three agents have significant difference in the effect of the anti-termite. when the concentration is 125mg/L, the agents can prevent completely the termite from decaying. The concentration of EW and SC reaching at 1000mg/L can achieve the anti-moth effect of the EC at 250mg/L to Coptotermes formosanus. (3) The experiment of the toxic soil pillar repelling termites indicates that there is about 3-4cm length soil were permeated by the toxicity. 15.625mg/L can be determind whether or not the Reticulitermes speratus could drill through the 5cm length barriers spiked with bifenthrin. The three agents have no significant difference to repell Reticulitermes speratu. The value is 250mg/L for Coptotermes formosanus, and the repellent effect seems more outstanding for EC. The concentration of preventing termites from passing the soil pillar is higher than the half lethal concentration.In conclusion, the effect of SC and EW for wood protection and soil barrier is not as good as EC. But if properly increasing the agent concentration, the desired effect can be achieved. EW and SC deserve the promotion because they are less polluted to the environment, low-poisoned to human beings and save the petroleum resource.