| The whitefly,Bemisia tabaci (Gennadius) is one of the most devastating pests worldwideand occurs in subtropical and tropical agriculture. Over the past20years, Bemisia tabaci hascaused tremendous losses in several provinces and cities in China. At the beginning of lastcentury, the outbreaks of B. tabaci populations occurred in Zhangzhou, Quanzhou, Longyanregions in Fujian province,China. In Fujian province, the control of B. tabaci has relied onchemical agent for all the times. Although, the use of chemical insecticides can cause short-term(acute) effects, especially some neonicotinoid insecticides. The irrational use of chemical agentshas brought about a series of problems, including insecticide resistance increasing quickly in B.tabaci in short time. These problems cause people to reconsider the control strategy of pesticides.In attempting to solve the problems caused by resistance of B. tabaci in Fujian province, one isto study the mechanism of insecticide resistance, another is to evaluate about effect factors on B.tabaci resistance. So we can formulate rational and scientific control strategy for B. tabaciaccording with local agriculture production. For this reason, in this paper, firstly, throughmonitoring and comparing of B. tabaci resistance, the present situation and trend of insecticideresistance in field-collected populations of B. tabaci were defined in Fujian province. Secondly,the influence factors of resistance, including biotype of B. tabaci, population diversity andgenetic differentiation, host plant species, temperature and sublethal effect of pesticides, weresurveyed and analyzed to clarify the key effect factor on B. tabaci resistance in Fujian. On thebasis of these studies, we can construct the corresponding sustainable PUSH-PULL strategy andbiological control measures, and make a good foundation for resistance management of B. tabaciin Fujian province. The results were as follows:(1) Resistance to eight insecticides in field populations of Bemisia tabaci from six regions(Fuzhou, Zhangzhou, Longyan, Sanming, Nanping, Ningde) of Fujian Province was monitoredby adult leaf-dipping bioassay. The resistance levels to neonicotinoid insecticides developedrapidly in field-collected populations of B. tabaci. Especially, Zhangzhou population, theresistance levels to imidacloprid and thiamethoxam had already developed from medium to highlevel in2005and2009(28-102.53-fold to imidacloprid,29-227.74-fold to thiamethoxam). The populations in other regions exhibited moderate levels of resistance to neonicotinoid insecticides(19.7244.76fold to imidacloprid,21.1851.64-fold to thiamethoxam).(2) The biotypes of different geographical populations of Bemisia tabaci in Fujian provincewere identified base on mtDNACOI molecular marker and squash silverleaf determination. Thebiotype B and FJ were detected. In addition to the population collected from Zhangzhou, whichwas the biotype FJ, the10field-collected populations of B. tabaci were biotype B. Due to notdetecting biotype Q, the identification of biotypes showedthat the biotype B of B. tabaci was stilldestroying agricultural and production in Fujian province over the past10years, and theresistance of B. tabaci was not caused by the recent invasion of biotype Q or others.(3) The genetic analysis of eight field-collected populations of B. tabaci were characterizedbase on the ISSR, RAPD and mtDNACOI molecular markers in Fujian province. The resultsshowedthat the genetic diversity of field-collected B. tabaci in Fujian was abundant, and acertain level of genetic differentiation has appeared among different geographical populations.Simultaneously, The results also showedthat the Fujian populations of B. tabaci own strongability of genetic evolution and adaptability under the pesticide selection pressure. The geneticdifferentiation of B. tabaci can improve its own survivability under adverse conditions.(4) The sensitivity of B. tabaci to different pesticides was studied under different host plantsand different temperature conditions. The results showedthat the sensitivity of B. tabaci could beaffected by host plants and temperature, but this kind of impact factors was difficult to causeinsecticide resistance to increase more than several dozens or hundreds of times. We canconclude that the most important reason of resistance increasing rapidly might be due to highstrength use of neonicotinoids.(5) The resistance screening of laboratory population was used with sublethal doses(LC20)of imidacloprid in the laboratory in2009. After14generations, the resistance of B. tabacito imidacloprid was increased by8.64-fold (LC20value from10.0ppm to100.0ppm). Therealized heritability estimate(h2) with imidacloprid screening was0.198. The results showed thatcontinuous screening with sublethal doses of imidacloprid could further increase the resistancelevel of B. tabaci, and the sublethal effect of insecticide was closely associated with resistance ofB. tabaci. (6) Firstly, the host plants of B. tabaci and the adaptability relationship between B. tabaciand different host plants were investigated. Secondly, the control effect of trap plants (cucumber)and repellents (capsaicin) were evaluated, including biological control (Serangini japonicum).Finally, we integrated the application of trap plants(cucumber), yellow board, repellents(capsaicin) and combined with biological control technology (Serangini japonicum), to constructPUSH-PULL strategy and biological control measures for sustainable control of B. tabaci inFujian province.
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