Population density of onion thrips, Thrips tabaci and the predatory bug, Orius niger on seven potato genotypes

The onion thrips, Thrips tabaci (Lind.), is a pests of potato, Solanum tuberosum L. Orius niger Wolff is an important predator of this pest in Iran. In this study, we investigated the population densities of T. tabaci and O. niger on seven potato genotypes namely Agria, Savalan, Morene, Kondor, Diamant, PI397082-2, and PI397097-2 under field conditions during 2011 and 2012. In this study, the lowest thrips densities were observed on Savalan cultivar, in both years. Moreover, the density of predatory bug on Savalan was significantly higher than the other tested genotypes. In addition, amongst the six tested growth stages of potato, the highest density of predatory bug was observed on flowering stage of the seven tested genotypes. Our results suggest that Savalan cultivar is most suitable for predatory activity of O. niger amongst tested genotypes of potato; therefore cultivation of Savalan integrated with O. niger could provide effective and sustainable management of T. tabaci in the region.