Der Artenkomplex Thrips tabaci: räumliche und zeitliche Verbreitung und sympatrische Populationen

The onion thrips Thrips tabaci Lindeman (Thysanoptera: Thripidae) is a highly polyphagous, cosmopolitan pest causing severe losses in both protected and field crops. Onion and white cabbage are primary host plants of this pest, and both are economically important crops cultivated in Hungary and Austria. Tobacco, a third primary host plant of T. tabaci, is also grown in both countries. Molecular studies have revealed that T. tabaci is a cryptic complex of species consisting of three different lineages, reproducing in 2 different modes, arrhenotoky and thelytoky. The lineages, being adapted to their primary host plants, perform differently on onion, white cabbage and tobacco. The proposed project´s scientific objective is to study the spatial and temporal distribution and the relative abundance of the three known T. tabaci lineages in Hungary and Austria. While all three lineages are found in Hungary, their spatial distribution in Austria is not known yet. Moreover, the three lineages may have different activity periods throughout the season, but their temporal distribution has never been studied in detail. Thrips sampling at selected locations in Hungary and Austria will close this knowledge gap, providing information on the distribution of the three lineages on onion, white cabbage and tobacco. Furthermore, it would increase the chance to encounter and identify sympatric populations: It might prove the existence of natural hybridization in the T. tabaci species complex, an aspect with possible implications for host use. The Hungarian project partner has developed a specific primer and a respective protocol as quick and reliable identification tool for the determination of adults of all three T. tabaci subspecies. To date, only Hungarian samples have been tested with this tool, and processing a large number of samples from Hungary and Austria will help to optimise their use and reliability. Establishing the method in the laboratory of the Austrian project partner will ensure harmonised and accurate future use of the tool in both countries. Insights into the distribution and abundance of the T. tabaci lineages may help thrips management in the field, allowing farmers to grow specifically selected crops in rotation to interfere with the life cycle of this pest.