Abstract: 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.

Key words: Bemisia tabaci B-biotype, Trialeurodes vaporariorum, high temperature, low temperature, survival