Molecular characterisation of Thrips tabaci Lindeman, 1889 (Thysanoptera: Thripidae) populations in Hungary based on the ITS2 sequences

Thrips tabaci is comprised of morphologically indistinguishable 'biotypes'or cryptic species with various host ranges, populations propagating by distinct modes and with different virus vector ability.T. tabaci 'communis-type' has wide host range while T. tabaci 'tabacitype' is associated only with tobacco.Since tobacco was introduced to Europe only 500 years ago, we supposed that the differentiation of the T. tabaci 'tabaci-type' population had to begin on another host species that is native to the Palaearctic region.To observe the interaction between host plant preference and molecular characteristics, maximum likelihood tree based on the sequences of the internal transcribed spacer 2 region of the rDNA (ITS2) of Thrips tabaci specimens collected on tobacco, onion, cabbage and distinct weed plants from various locations of Hungary was analysed.According to the results of the phylogenetic study the only common host for Thrips tabaci 'tabaci-type' and Thrips tabaci 'communis-type' was Solanum nigrum.This finding supported our hypothesis that the splitting process of the two main molecular clades could have happened on this solanaceous host species.To compare our results to that of the literature based on cytochrome oxidase I (COI) sequences further investigations with these markers (mitochondrial DNA markers) still needed.