Study On Increased Effect Of Pesticides And Repellent Confected By Chitosan

It is difficult for conventional pesticides to contact target pests due to its formulations and administrating methods. The residual in the environment is harmful to people and pollutes environment. Many literatures reported that the losing rate of pesticides from the targets reached 60-90%. In fact, the effective component of pesticides acting on pests was only 0.1%. So it is quite urgent to save the short-term pesticides in a formulation, guaranteeing the necessary dose in the targets sites, and sufficient effects and action duration. So the controlled releasing formulations of pesticides have emerged.According to literatures, the Chitosan was natural macromolecular polymer and have been widely applied to clinical pharmaceutics preparation. Chitosan could control the release of medicine, and reduce the side effects of medicine. In the present paper, the study was about to apply Chitosan to the sanitarian field of the pest control and to research the effect on pesticides and repellent.Methods: (D Put the high effect cypermethrin of confected-recipe and non-confected-recipe brushed onto the glass, gauze and painting board. After they are dry, we treated them by exposed in the air, exposed in 56癈and simulating rain. We detected the killing effects of the treated board and observed theeffective duration of the pesticides and KT50 in the different time according to the National standard. (2) We observed the effectual protective time when the Deet was daubed on the human's skin, and detected the lustrating-effects. (D The effective durations of the high effect cypermethrin would be observed after the same reagents were applied to the experimental spots. ?We observed the protective results of the Deet on body in the experiment periodically.Results: The indoor investigation the he indoor investigation showed that the effective duration of high effect cypermethrin confected by Chitosan was increased from 3 months to over 4 months on the glass and net surfaces, and the KT50 was less than 7min within 3 months, and the pesticidal effects were scarcely influenced by raining water. The protective time of Deet confected by Chitosan for people against mosquito was prolonged from 4 hours to more than 8 hours, and the compound preparation did not irritate human body obviously. The field trial showed that the high effect cypermethrin confected by Chitosan could control pests from 2 months to more than 3 months, and the effectual protective time of Deet confected by Chitosan was prolonged from 2.83h to 6.4h, and the protective efficiency of Deet confected by Chitosan was 80% for 4 hours. The study proved that the applying effects of pesticides and repellents were increased and its effective durations were prolonged obviously by Chitosan.Conclusions: ?Confected the Chitosan, the effective duration of the high effect cypermethrin would be prolonged one month at least. The study showed that Chitosan could obviously control the release of high effect cypermethrin. (D Mixed the Chitosan, the protecting time of the Deet would be prolonged 4 hours and showed that Chitosan could control the release of Deet. (3) We utilized directly the Chitosan to confect the controlled-release formulations of high effect cypermethrin and Deet, but the further study would beneeded to detect their maximum effective duration and comparison with other pesticides and repellents.