Abstract: The vertical distribution law of Bemisia tabaci B-biotype adults on Euphorbia pulcherrima under temperatures of 18℃, 25℃ and 32℃ was studied in laboratory. The results showed that B. tabaci adults mainly clustered on the leaf back of E. pulcherrima, and the numbers of B. tabaci adult on the different leaf layers were significantly different, with the sequence of lower leaves>middle leaves>upper leaves. Furthermore, there was significant correlation between E. pulcherrima leaf-position and B. tabaci adult numbers, and B. tabaci adults mainly clustered between top third leaf and top twelfth leaf. With the increasing of temperature, the occurrence quantity of B. tabaci adult moved to under-part leaves gradually. Under the background of global warming, the results could provide reference basis for the monitor and control of B. tabaci on flowers.

Key words: Bemisia tabaci B-biotype, Euphorbia pulcherrima, vertical distribution, leaf layer, leaf-position