Abstract: 【Aim】 To reveal the distribution and infestation status of Bemisia tabaci cryptic species, a systematic and comprehensive survey on its species composition was conducted in Shandong, China. 【Methods】 Sixty-nine collections of adult whiteflies were sampled from 22 locations distributed in 15 counties in Shandong during July-August, 2013, the cryptic species of the 1 387 individuals was determined based on mitochondrial cytochrome oxidase I (mtCOI) PCR-RFLP method, and the percentages of B.tabaci Q on different host plants and in geographical regions were analyzed. 【Results】 The results showed that the percentage of B. tabaci Q was 100% in 17 locations and was >90% in five locations (Weifang, Heze, Tai’an, Zibo, and Linyi), whereB.tabaci B was found with low percentage (<10%). The average percentages of B.tabaci Q did not differ significantly among the populations on the five hosts (eggplant, pepper, cucumber, tomato and cotton) and in the three areas (the western plain region, the eastern hilly region and the central mountains region). 【Conclusion】 The results indicate that B. tabaci Q is predominant in all the investigated locations, suggesting that B. tabaci Q has completely displaced B.tabaci B in most regions of Shandong, China. 

Key words: Bemisia tabaci, cryptic species, biological invasion, competitive displacement, Shandong