The Monitoring And Occurrence Of Bemisia Tabaci Biotype And Control Technique Of B.Tabaci In Jiangsu Province

The whitefly Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodoidea) is a herbivorous insect with wide host range, and is widely distributed in the world including more than 100 countries and regions. B. tabaci is one of the most important pests of a range of agricultural, horticultural and ornamental crops, and is also the vector of several plant viruses. In Jiangsu Province, both invasive biotypes and indigenous biotypes of B. tabaci have been reported, and the invasive biotypes are the most destructive species. In order to determine the distribution of different biotypes of B. tabaci and the occurrence and damage through the years, a series of field samplings have been conducted on major host plants in Jiangsu. And for the prevention and control of B. tabaci, this paper selects several different pesticides to determine bioassay in the laboratory and control effects in outdoor. At the same time test trapping effect of four kinds of attractants of B. tabaci. The main results are as follows:1.We investigated the main hosts and the occurrence degree of B.tabaci in 13 cities of Jiangsu Province during 2014-2015. The results showed that the occurrence degree of B. tabaci at different regions of Jiangsu Province was the degree of the North> the degree of the South> the degree of the Center in 2014; The occurrence degree of B. tabaci at different regions of Jiangsu Province was the degree of the North> the degree of the Center> the degree of the South in 2015. The results of the analyses on the occurrence degree of six hosts of B. tabaci showed that tomato> eggplant> cucumber> pepper> humulus> pumpkin, which means that the tomato suffered the most serious damage and the pumpkin suffered the least damage.2. We have monitored the biotype of B. tabaci in Jiangsu Province during 2014, there are 1356 individuals from 64 samples that we monitored. In our survey we found that 63 sampling locations exist Q biotype in a total of 64 sampling locations, only in Danyang can not detect the Q biotype and the occurring frequency of Q biotype is 84.88%. Q biotype is still the dominant biotype in Jiangsu. B biotypes have been detected in 15 sampling locations and the occurring frequency of B biotype is 15.12%. What is noteworthy is that the occuring frequency of B biotype was more than Q biotype in Peixian, Hailing District of Taizhou, Danyang, Zhoutie of Yixing and Wujiang. And in these areas of B biotype existed, the occuring frequency of B biotype individuals which from South of Jiangsu was the highest (65.37%).3. The results of the investigation in 2014 showed that B. tabaci on the outdoor vegetables in Jiangwang region, Yangzhou emerged in early April, and disappeared in late December, and there were one peak during this period, which appeared in late July; In 2015, B.tabaci emerged in middle April, to the end of November, there are still existence of B.tabaci, and there are two peaks in early June and early August. The B.tabaci population density in 2014 is higher than 2015. The results of the detection of biotype showed that B.tabaci in this region through out the years all belonged to Q biotype during 2014-2015.4. The results of bioassay in the laboratory showed that toxicity of abamectin on B. tabaci adult is highest (LC50:2.8609mg/L); and toxicity of y-cyhalothrin on B. tabaci adult is minimum (LC50:389.1049mg/L). Spinetoram have no insecticidal effect for B. tabaci adult. The order of 9 kinds of insecticides toxicity on B.tabaci is:abamectin> acetamiprid> lambda cyhalothrin> beta cypermethrin> sulfoxaflor> flonicamid> spirotetramat> thiamethoxam> y-cyhalothrin. The control effect of 10 kinds of insecticides is in turn:thiamethoxam> abamectin> sulfoxaflor > flonicamid> y-cyhalothrin> acetamiprid> spirotetramat> lambda cyhalothrin> beta cypermethrin>Spinetoram; 9 kind of mixtures control effect in field experimen showed that there are 6 kinds of mixed agent on the control effect of B.tabaci is good than single agent, and the best mixtures are abamectin with three neonicotinoids.5. The monitoring results of four B.tabaci attractant showed that:the attractant NO.1 is the best effect in this four consecutive monitoring, there are significant differences with the control group; The followed attractant are NO.2 and NO.4; The effect of attractant NO.3 is poor, there was no significant difference with control group.