Abstract
AbstractBemisia tabaci is a complex of putative species that exhibit a strong geographical pattern. Crossing experiments have revealed various degrees of reproductive isolation between these nascent species, ranging between fertile first‐generation hybrids (F1) and no F1 at all. However, the relevance of these results under natural conditions is generally not known. The worldwide invasion of the putative species Middle East‐Asia Minor 1 (MEAM1) has caused secondary contacts between allopatric species, which in turn provide an opportunity to detect potential hybrids in nature. A total of 346 female B. tabaci were collected in 2003 and 2005 in the North East of Morocco and assigned to MEAM1 (119), Mediterranean (Med) (225) and a new putative species (2) using mitochondrial cytochrome oxidase (mtCOI) gene sequences. MEAM1 and Med individuals were characterized at seven microsatellite loci. MEAM1 and Med were found to be sympatric in 11 of 12 samples (6 fields/year). As previously reported from Spain, MEAM1 frequency decreased over time. The genetic data are consistent with a recent introduction of MEAM1. A Bayesian clustering analysis (Structure) distinguished two groups, which were 100% consistent with the mtCOI groups. From several lines of evidence, two individuals were identified as hybrids. Assignment profiles using NewHybrids and allele composition indicated that they were not F1 hybrids. The results are discussed in relation to the secondary endosymbiont infection status determined on a sample of individuals, and the contrasting outcomes of the reported crossing experiments between MEAM1 and Med.
Highlights
The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) (Fig. 1) is a pest and virus vector in all warm-to-hot climate regions
Using Med- and Middle East-Asia Minor 1 (MEAM1)-specific polymerase chain reaction (PCR) primers targeted to the mitochondrial cytochrome oxidase I (mtCOI) gene, 225 individuals were identified as belonging to Med and 111 to MEAM1, whereas 11 exhibited nonconclusive profiles (Table 1)
Nucleotide sequence data generated for these 11 individuals revealed that eight of them belong to the West Mediterranean Q1 group (Chu et al 2008; Tsagkarakou et al 2012) within Med, one belongs to a distinct species of whitefly, Trialeurodes vaporariorum, and two to a new genetic group of B. tabaci that is sister to the putative “Italy” species (Fig. 2)
Summary
The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) (Fig. 1) is a pest and virus vector in all warm-to-hot climate regions. The high genetic differentiation between populations and biological differences with respect to host plant and reproductive incompatibility has triggered an exciting debate as to whether B. tabaci is a complex species consisting of various biotypes or races, or a species complex (Brown et al 1995; Frohlich et al 1999; De Barro et al 2005). Most recently, based on genetic and biological data, Dinsdale et al (2010) and De Barro et al. Ecology and Evolution published by John Wiley & Sons Ltd. Ecology and Evolution published by John Wiley & Sons Ltd
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
