B型烟粉虱和温室白粉虱在温度逆境下的生存特性比较

为了明确B型烟粉虱和温室白粉虱在温度逆境下的生存特性对其种群发展的影响，通过进行高温和低温暴露试验，研究了B型烟粉虱和温室白粉虱卵、伪蛹、成虫在37℃，39℃，41℃，43℃，45℃下暴露1～2 h后的存活率，以及这两种粉虱卵、2～3龄若虫、伪蛹和成虫在2℃下暴露1～12 d后的存活率。结果表明：两种粉虱的卵、伪蛹和成虫在37℃～45℃下暴露1～2 h，其存活率均随着温度的上升而降低；但在相同处理条件下B型烟粉虱3种供试虫态的存活率要高于温室白粉虱。B型烟粉虱在2℃下暴露2～12 d，各供试虫态的存活率迅速下降，卵、2～3龄若虫、伪蛹在2℃下暴露12 d后均不能存活，成虫在2℃下暴露4 d后也全部死亡；而温室白粉虱卵、伪蛹在2℃下暴露12 d后其存活率还能超过45%，成虫在2℃下暴露7 d后仍有80.9%能够存活。结果说明，B型烟粉虱和温室白粉虱对温度逆境的适应性存在差异，B型烟粉虱对高温的适应性要高于温室白粉虱；温室白粉虱对高温敏感，但对低温的适应性要显著高于B型烟粉虱。据此推测，两种粉虱对温度逆境适应性的差异是导致其种群发生存在差异的一个重要原因。

Survival characteristics of Bemisia tabaci B-biotype and Trialeurodes vaporariorum (Homoptera: Aleyrodidae ) after exposure to adverse temperature conditions

The survivals of Bemisia tabaci B-biotype and Trialeurodes vaporariorum (Homoptera: Aleyrodidae) were studied after exposure to high and low temperature to determine the effects of adverse temperature conditions on the population development of two whitefly species in China. The eggs, red-eyed nymphs and adults of two whitefly species were exposed to five temperatures, 37℃, 39℃, 41℃, 43℃ and 45℃, for 1-2 h in climatic incubators. The results indicated that the survivals of both whitefly species at the three tested developmental stages decreased with the increase of temperature, but the survials of T. vaporariorum decreased faster than that of B. tabaci B-biotype in the same condition. When the eggs, 2-3 instar nymphs and red-eyed nymphs of two whitefly species were exposed to 2℃ for 1-12 d, the survivals of four tested developmental stages of B. tabaci B-biotype were significantly affected by low temperature; the eggs, 2-3 instar nymphs and red-eyed nymphs all died after exposure to 2℃ for 12 d, and no adults could survive after exposure to 2℃ for 4 d. However, more than 45% eggs and red-eyed nymphs of T. vaporariorum could develop to the next stage after exposure to 2℃ for 12 d, and the survival rate reached 80.9% when the adults were exposed to 2℃ for 7 d. Thus, there were prominent differences between two tested whitefly species in their adaptation to adverse temperature. B. tabaci B-Biotype was more sensitive to low temperature and had higher tolerance to high temperature than T. vaporariorum. It is inferred that the difference of adaptability to adverse temperature may be one important mechanism that leads to interspecific differentiation in dynamics of the two whitefly species in China.