Species Distribution Of Whiteflies In Liaoning Province And The Impact Of Temperature On Their Growth

Bemisia tabaci(Gennadius)and Trialeurodes vaporariorum(Westwood)are both important invasive alien pests in China. They have a wide host range, strong drug resistance, breed speed quickly and have caused a lot of damage to vegetable, flower and plant. Although they are relate species, there was significant difference in living habits, occurrence rules, prevention and control measures. Therefore, conducting a full and ongoing investigation of whiteflies in Liaoning is important to Integrated Pest Management.Considering the adaptation ability to temperature of the whiteflies, it will be influenced by the environment facts, such as illumination and humidity. And the experimental whiteflies belong to different geographical colonies, which will also lead to the same temperature. For the reason, studying the impact of temperature on someone kind of whiteflies then comparing the diverse results studied by different scholars, this method of research is not meaningful. So it is necessary to observe the adaptability to temperature of whiteflies in Liaoning under different temperature. It is the basis of spatial pattern of population and population changing and is also an important theoretical foundation of forecasting mechanism to whiteflies.The composition of whiteflies communities at Liaoning Province was investigated, and we compared the adaptability to temperature of two whiteflies population in Liaoning. The fatty acids were analyzed in whiteflies because of cold resistance between Bemisia tabaci and Trialeurodes vaporariorum. The results are as follows:1) Through the mtDNA COI genetic sequencing, we found that there are Trialeurodes vaporariorum, MED Bemisia tabaci and MEAM1 Bemisia tabaci. In these samples, the Trialeurodes vaporariorum are major, such as MS, SHH, XM, LZ, TL, DD, DW. In the other samples, the MED Bemisia tabaci are major. Only in DW and SHH, MEAM1 Bemisia tabaci were founded.2) The threshold temperature and effective accumulated temperature of every instars of MED Bemisia tabaci and Trialeurodes vaporariorum were studied under five constant temperature of 18℃,22℃,26℃,30℃,34℃. The results show that the development time of the two kinds of whiteflies was shortened with the temperature increasing under 18℃-30℃, but increased under 34℃. As to survival rate, the Trialeurodes vaporariorum was significantly higher than that of Bemisia tabaci under 18℃ and 22℃, and Bemisia tabaci (Gennadius) was significantly higher than that of Trialeurodes vaporariorum under 30℃ and 34℃ (P< 0.05).There was no significant difference between the two kinds of whiteflies’survival rate under 26 degrees (P>0.05). That is to say the Trialeurodes vaporariorum in Liaoning survive better under 22℃, and 26℃ is more suitable for Bemisia tabaci.3) Trialeurodes vaporariorum contain more palm oil, stearic acid, oleic acid and linoleic acid than Bemisia tabaci (P<0.05), the same as fatty acid total content and unsaturated fatty acid content. So we speculate that this is one of reason that affect whiteflies’s cold resistance and distribution in Liaoning.