Resistance Selecting And Resistance Mechanism Of Tetranychus Urticae Koch To Spirodicofen And Clofentezine

The resistance selection of Tetranychus urticae koch to spirodicofen and clofentezine, the cross-resistance test of resistance stains to 18 insecticides and acaricides and the physiological and biochemical analyses were studied by artificial inoculation in Lab.The purpose of research was to make sure the resistance evolution and resistance mechanism for the resistance monitor technology to spirodicofen and clofentezine, the selection of effectively synergists and the management of the resistance.The results obtained are summarized as follows.The resistance selecting and resistance evolution about Tetranychus urticae koch to spirodicofen and clofentezineTetranychus urticae koch was treated by Spirodiclofen and clofentezine ,respectivaly,the SP-R strain,the CL-R strain were obtained Toxicity of both to Spirodiclofen and clofentezine were tested by means of slide-dip method bioassay, in addition sensitive strain.The result showed that the development resistant of two strains were slow at the beginning, stabile at mid-term but faster at later period. RI of the CL-R strain to spirodiclofen was 58.83 after 26 generations of resistance selected. RI of the CL-R strain to clofentezine was 122.25 after 21 generations of resistance selected.Testing the cross-resistance tetranychus urticae koch to spirodicofen and clofentezine strains about 18 pesticidesThe SP-R had obvious cross resistance to fenpropathrin and cyhalothrin (resistance index, RI>5.00). But the SP-R had no significant cross-resistance to fenbutatin oxide,clofentezine, celastrusangulatus, avermectins,cypermethrin, pyr-clofentezi, dicofol, pry-isocarbophos, azocyclotin, pyridaben, omethoate (RI<5.00) and the cross-resistance to liuyangmycin, chlorpyrifos, hexythiazox, die-clofentezi, fenpyroximate were negative cross resistance and the RI was less than 1. The CL-R had obvious cross resistance to fenpropathrin, cyhalothrin, cypermethrin, liuyangmycin, pyr-clofentezi, pyr-isocarbophos and pyridaben (resistance index, RI>5.00).But the CL-R had no significant cross-resistance to avermectins, dicofol, azocyclotin, omethoate, Spirodiclofen, fenpyroximate, chlorpyrifos,die-clofentezi (RI<5.00)and the cross-resistance to celastrusangulatus, fenbutatin oxide, hexythiazox had negative cross resistance and the RI was less than 1.The biochemistry mechanism of Tetranychus urticae koch resistance strains to spirodicofen and clofentezine. The activity of carborylesterase of SP-R21 was 1.03-fold than sensitive strain(S); the activity of phosphoric acid was 1.72-fold than S strain. The activity of alkaline phosphoricr was 1.29-fold than S strain. The activity of Glutathione-S-transferase between resistance strain and sensitive strain was 1.72-fold. The Mixed funcyion oxidase (MFO) activity of SP-R was the 1.27-fold than the S strain.The carboxylesterases activity of the CL-R 21 was obvious difference to the S strain and the multiple of both strains was 2.26-flod. The activity of the phosphoric acid of the CL-R 20 was the 2.06-flod than the S, and the trend about activity of phosphatase alkaline was increased. The CL-R 20 was the 1.98-fold higher than the S. The results of mixed funcyion oxidase (MFO) showed that The CL-R 20 was the 26.68-fold higher than the S. The results showed that the resistance of Tetranychus urticae koch to spirodicofen and clofentezine was related with PBO, SV, DEM, TPP.Synergetic action of 6 synergists with spirodicofen and clofentezine The synergism was tested separately between 4 synergists (PBO, SV, DEM, TPP,) and Spirodiclofen and clofentezine on Tetranychus urticae koch for selecting the best synergists respectively. The result showed that the synergistic ratio (SR) of PBO, SV, DEM , TPP with Spirodiclofen was1.81,1.03,1.53,1.67 respectively. The synergistic ratio(SR) of PBO , SV , DEM ,TPP with clofentezine was 5.94,1.43,1.49 and 1.22 respectively. These all had synergistic effect. The silicone also had synergistic effect on Spirodiclofen and clofentezine, and the synergistic ratio was 1.35 and 2.02 respectively; the synergistic ratio (SR) of 885 was 2.55 , 2.72 and the synergistic effect was significant.