The Toxic Symptoms And Penetration Effect Of Integument Of Tetranychus Cinnabarinus After Treatment Of Curcumin

Tetranychus cinnabarinus Boisduval belongs to Arachnoidea Acarina, Tetranychidae Tetranychus Dufour, with its tiny shape, which is distributed in farmland, fruit and greenhouse all over the world, it is a worldwide harmful economic and food crops pest. Long-term chemical control, not only pollutes the environment and damages the balance of natural ecology, but also increased the resistance of T. cinnabarinus.Curcuma longa L.belongs to the ginger family (Zingiberaceae), Curcuma L, which is a perennial herbaceous plants, extractive of curcumin and its derivatives have significant acaricidal activity, but there are differences of curcumin derivatives with different acaricidal activity. So far, study on the acaricidal mechanism of mites integument has seldom relevant reports. In this experiment, T. cinnabarinus was regarded as indicator biological mite, we study the toxic symptoms and penetration effect of integument of T.cinnabarinus after the treatment of curcumin. The main results are as follows:1. The toxic symptoms induced by curcumin is similar to abamectin on T. cinnabarinus.Toxicities of five pesticides, Curcumin, Scopoletin, Avermectin, Pyridaben TC and Spirodiclofen TC, to T. cinnabarinus were measured. The results showed that the median lethal concentration of the five pesticides to T.cinnabarinus in 48h were 0.0095mg/L, 0.955mg/L, 661.20mg/L,3055.85mg/L,1886.40mg/L, respectively.After treatment of curcumin, the toxic symptoms are as follows:the head kept on twisting,2-3 times per second between Oh and24h, in a state of excitement, duration of each movement could reach 50-60s, interval is 5-6s.24hs later, filament is emerged all over the head and feet,4-6 feet are in motion, but the frequency is reduced.72h later, most of the mites were in coma, only mechanical stimulation could make them move, and the feet could not straighten, diarrhea phenomenon appeared in empennage of some mites, the mites was obviously shrunken and the colors of body darkened.96h later, color of body gradually became black, color of feet became brown, head shrink further, until at the time of 168h the mite was dead. From comparing the toxic symptoms, we conclude that the toxic mechanism of curcumin is similar to abamectin on T. cinnabarinus.2. Curcumin could significantly influence the the morphological changes and water loss of T. cinnabarinus.Then we dipped the slides with the mites into each pesticide solution at the concentration of median lethal, the length shrinkage rate under the treatments of curcumin and scopoletin differs significantly from the other pesticides and blank at the time of 72h and 168h, the length shrinkage rate reached 23.17%,19.46% in 72hs, and 35.94%,35.79% in 168hs respectively. Water loss rate under the treatment of spirodiclofen TC, curcumin and scopoletin reached 66.67%,72.59%,69.27% respectively, which has significant differences compared with other agents and blank at the time 96hs. The research confirmed that curcumin and scopoletin, can significantly influence the morphology and water content of T. cinnabarinus, curcumin is similar to the growth regulator(spirodiclofen) in the water loss of T.cinnabarinus, and more research is needed to explain the mechanism.3. The penetration rate of curcumin into the integument of T. cinnabarinus reached maximum of 2.253% at 31 degree in 24h.Stability of curcumin was measured in the experiment, condition of the climatic cabinate was set as the below:the humiditywas 80%, intensity of light was 150001x, the proportion of light and darkness was 14 to 10. The results showed that the content of curcumin was stable in 48hs in different temperatures and contriations.The dynamic effect of penetration of curcumin into the integument of female adults of the carmine spider mite, T. cinnabarinus, was studied in the chapter. The experiment was conducted under three concentrations of curcumin with 1.25mg/mL,2.5mg/mL,5.0mg/mL at 25℃ and five temperatures (22,25,28,31,34℃) at concentration of 2.50mg/mL with the treatment of spraying curcumin to the mites on the leaf, condition of the climatic cabinate was the same as the previous chapter. Then the body fluid of T. cinnabarinus was extracted after 3hs,6hs,12hs,24hs,36hs, 48hs, and the content of curcumin in T. cinnabarinus body fluids was detected by using the method of HPLC. The results showed that, at the temperature of 25℃, penetration rate tended to keep increasing with the increase of concentration, until reaching 1.786% among the three concentrations; at the concentration of 2.5mg/mL under five temperatures, penetration rate reached a maximum of 2.253% at 31℃ in 24h; The content of curcumin in the body fluids increased gradually as the time went by during the first 24hs, then it decreased gradually in the next 24hs. The reason for the decline of penetration rate relates to the metabolism of T. Cinnabarinus, but needs further investigation.