Evaluation of Effectiveness of Several Insecticides on Bemisia Tabaci(Gennadius) and Application Study of Nitenpyra
|Course||Agricultural Entomology and Pest Control|
|Keywords||B. tabaci Nitenpyram Biological activity test Mode of action Applied Technology|
Tobacco whitefly Bemisia tabaci (Gennadius) is one of the important pests facilities vegetables. For chemical control of B. tabaci we evaluated the effect of the prevention and treatment of several different types on Bemisia tabaci, system the nitenpyram of the mode of action of B. tabaci, mechanism of action and field application technology and nitenpyram amine resistance risk assessment, the main results are as follows: 1. measured several different types on Bemisia tabaci adults, nymphs, eggs indoor biological activity and prevention effect. Bioassay results show that: the avermectin B. tabaci adults virulence highest, its LC 50 2.286 mg / L; followed Actara, nitenpyram, imidacloprid, imidacloprid Pymetrozine its the LC of 50 , respectively to 6.411mg / L, 13.826 mg / L, 36.814 mg / L, 73.621 mg / L Buprofezin strongest killing effect of B. tabaci eggs, its LC 50 77.147mg / L. Abamectin B. tabaci nymph young and elderly nymphs showed higher virulence, its LC 50 2.588 mg / L, 4.440 mg / L; followed nitenpyram , thiamethoxam, imidacloprid, Pymetrozine ketone, young nymph of B. tabaci LC 50 6.373 mg / L, 10.744 mg / L, 25.311mg / L, 35.852 mg / L on the B. tabaci old nymphae LC 50 were 9.541 mg / L, 12.800 mg / L, 62.122 mg / L, 87.667mg / L, cypermethrin, chlorpyrifos, lambda-cyhalothrin, flutter the lice Spirit of B. tabaci nymph young and elderly nymph LC 50 115.310 mg / L or more. The field trial showed that: 1.8% abamectin EC, 10% ene Acetamiprid amine agent, 25% thiamethoxam water dispersible granules, 25% WP pymetrozine than ideal medicament for prevention and control of B. tabaci, drugs after 9 days 2000 times control efficiency of 78.26% and 10% imidacloprid WP followed, nine days after the drug 2000 times when the control efficiency of 66.61%, 4.5% cypermethrin EC, 40% chlorpyrifos EC 2.5 % efficient cyhalothrin WP, 25% buprofezin WP against B. tabaci less effective, nine days after the drug control effect in 1000 times less than 61.58%. 2 nitenpyram different mode of action of B. tabaci adults and nymphs: the nitenpyram B. tabaci contact and absorption within the conduction and other modes of action. Two kinds of mode of action of B. tabaci adults and nymphs from strong to weak order uptake: contact action. Nitenpyram activity of several enzymes of B. tabaci. The results show that: nitenpyram LC 50 -dose treatment B. tabaci adults, the carboxylesterase performance of the test insects were as reversible inhibition, treatment after 12h, the specific activity of carboxylesterase is 0.6699, to increase over time, the specific activity of carboxylesterase significantly began to rise, more than the normal level, reaching 1.1717 to 48h. Realize acetylcholinesterase inhibition, acetylcholinesterase activity decreased with the prolonged duration of action, for 12h, vitality 0.9386,48 h ratio fell to 0.8041. 4. Environmental factors on the the nitenpyram application efficiency over obvious the impact. The results show that: The temperature play influential nitenpyram virulence, temperature rose to 32 ° C from 19 ℃ the nitenpyram of the virulence of B. tabaci enhanced 12.67 times. The holding effect tests showed that: nitenpyram amine agent 100mg / L treatment corrected mortality of B. tabaci adults 1-15 days between 80.18% -92.13%, with time, allyl Acetamiprid amines on B. tabaci anti-effectively reduce the corrected mortality of 15 days is still 80.18%. Nitenpyram different treatment of B. tabaci efficacy trials showed that: spray and IRRIGATING method is better, from quick result, spray in IRRIGATING it from the holding effect, IRRIGATING better than the spray, the two methods are significantly higher than the single leaf spraying and coated stems law. 6. Nitenpyram B. tabaci indoor resistance breeding, and studied the resistance of B. tabaci nitenpyram realized heritability and resistance risk. The results showed that, after the 8th generation breeding, whiteflies on nitenpyram slow the development of resistance, compared with before the breeding reduced sensitivity to 2.653 times the resistance to B. tabaci on nitenpyram realized heritability 0.1025, in 50% ~ 90% of the filter under pressure, to obtain 10-fold resistance, requires approximately 9-21 generations, and that the risk of resistant Bemisia tabaci nitenpyram.