1 SCIENTIFIC REPORTS | 7:40803 | DOI: 10.1038/srep40803 www.nature.com/scientificreports Dynamics of Bemisia tabaci biotypes and insecticide resistance in Fujian province in China during 2005–2014 Feng-Luan Yao 1,2 , Yu Zheng 1,2 , Xiao-Yan Huang 3 , Xue-Ling Ding 1,2 , Jian-Wei Zhao 1,2 , Nicolas Desneux 4 , Yu-Xian He 1,2 & Qi-Yong Weng 1,2 The whitefly Bemisia tabaci (Gennadius) is an important agricultural insect pest worldwide. The B and Q biotypes are the two most predominant and devastating biotypes prevalent across China. However, there are few studies regarding the occurrence of the Q biotype in Fujian Province, China, where high insecticide resistance has been reported in the B biotype. Differences in some biological characteristics between the B and Q biotypes, especially insecticide resistance, are considered to affect the outcome of their competition. Extensive surveys in Fujian revealed that the B biotype was predominant during 2005–2014, whereas the Q biotype was first detected in some locations in 2013 and widely detected throughout the province in 2014. Resistance to neonicotinoids (that have been used for more than 10 years) exhibited fluctuations in open fields, but showed a continual increasing trend in protected areas. Resistance to lambda-cyhalothrin, chlorpyrifos, and abamectin exhibited a declining trend. Resistance to novel insecticides, such as nitenpyram, pymetrozine, sulfoxaflor, and cyantraniliprole, in 2014 was generally below a moderate level. A decline in insecticide resistance in the B biotype and the rapid buildup of protected crops under global temperature increase may have promoted the establishment of the Q biotype in Fujian. e whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) has been one of the most devastating and economically important agricultural insect pests worldwide in recent decades 1 . It is a phloem-feeder and inflicts damage by direct feeding, secreting honeydew that triggers sooty mold, and by acting as a vector to plant viruses, especially geminivirus 1 . Bemisia tabaci has long been considered a complex species and the term “biotype” has been used to designate whitefly populations 1,2 . However, it was recently considered a cryptic species complex, involving at least 24 mor- phologically indistinguishable species 1 . In this study, however, we use the term “biotype” for consistency with most previous literature. e B and Q biotypes, recently named as Middle East-Asia Minor 1 and Mediterranean, respectively, are the two most predominant, damaging and invasive biotypes worldwide. In the past two decades, the B biotype spread into at least 54 countries, followed by the invasion of the Q biotype, which has been found in at least 10 countries 1 . ese two biotypes differ in a range of biological characteristics, including host plant range and adaptability, ability to transmit plant virus, copulation efficiency, composition of harbored symbionts, and expression of resistance to heat shock and insecticide 3–14 . ese differences contribute to the competitive outcomes between the two biotypes in various habitats. e B biotype is more adapted to open fields, whereas the Q biotype is more competitive in protected agricultural facilities 15,16 . In China, B. tabaci was first recorded in 1949, but did not cause significant damage until the mid-1990s 17 . However, in 2000, B. tabaci caused nationwide concern, when the notorious invasive biotype B largely sup- planted the indigenous whitefly species and plagued many provinces where it caused serious yield losses in many 1 Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou 350013, China. 2 Fujian Key Laboratory for Monitoring and Integrated Management of Crop Pests, Fuzhou 350001, China. 3 Provincial Station of Plant Protection and Quarantine, Fujian Provincial Department of Agriculture, Fuzhou 350001, China. 4 INRA (French National Institute for Agricultural Research), Univ. Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06903, Sophia-Antipolis, France. Correspondence and requests for materials should be addressed to Y.-X.H. (email: yuxianhe_faas@sina.cn) or Q.-Y.W. (email: wengqy@faas.cn) Received: 08 September 2016 Accepted: 12 December 2016 Published: 23 January 2017 OPEN