Journal of Insect Science (2008) 8 (4), 49-50

Fang-Hao Wan, Ming Xie and Xu-Hong Cui (2008)
Effects of heat shock on survival and fecundity of two whitefly species, Trialeurodes vaporariorum and Bemisia tabaci B-biotype
Journal of Insect Science 8 (4), 49-50
in P. A. Stansly and C.L. McKenzie, organizers: Fourth International Bemisia Workshop - International Whitefly Genomics Workshop, December 3-8, 2006, Duck Key, Florida, USA
Abstract: The effects of heat shock on survival and fecundity of two whitefly species, Trialeurodes vaporariorum (Westwood) and Bemisia tabaci (Gennadius) B-biotype, were examined after treatment for 1 h at five temperatures: 37, 39, 41, 43 and 45°C, under laboratory conditions. The objectives of the study were to evaluate the responses of both whitefly species to temperature stress and to understand why they might coexist in different areas with different population dynamics in China. The results showed that the heat tolerance of egg, red-eyed nymph and adult B. tabaci B-biotype was higher than that of T. vaporariorum. For both whitefly species, the response of adults to heat shock was related to sex; female adults were more heat tolerant than adult males. Heat shock had no detrimental effect on the pre-oviposition period of both whitefly species; female adults began to lay eggs in 2 d after a heat shock. However, the fecundity of both whitefly species was affected. When both sexes of B. tabaci B-biotype adults were heat shocked, the fecundity per female varied with the degree of heat shock, but there were no significant differences between heat-shocked and control female individuals. In the case of T. vaporariorum, the number of eggs produced per female was strongly affected by heat shock, significantly decreasing with the increasing heat shock temperature. Parental heat shock had substantial and lasting effects on egg hatching ability and the sex ratio of offspring of both whitefly species. Following the heat shock, ranging from 37 to 45°C, the proportion of hatched B. tabaci B-biotype eggs was reduced by 10-40% compared to the control, but no T. vaporariorum eggs survived when parental adults were exposed at 43°C for 1 h. The average sex ratio (expressed in % females) of B. tabaci B-biotype was about 55% after heat shock at 26, 37 and 39°C, respectively. When the temperature was above 43°C, the ratio of females decreased and that of males increased to over 60%. For T. vaporariorum, the mean sex ratio was about 54% when the heat shock temperature varied from 37 to 41°C, and there was no significant correlation between sex ratio and degree of heat shock. Our results indicated that T. vaporariorum was more sensitive to higher temperature than B. tabaci B-biotype. The different thermal adaptation between B. tabaci B-biotype and T. vaporariorum could be an important determinant in population dynamics and distribution of both whitefly species in China.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Fang Hao Wan

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Bemisia tabaci biotype MEAM1
	Trialeurodes vaporariorum