Abstract: Western flower thrips Frankliniella occidentalis Pergande occurring more commonly in tobacco can cause serious damages on yield and quality, in particular in recent Yunnan tobacco area. Thus, there’s an urgent need for biological control of F. occidentalis in tobacco industry. In this paper, we conducted the field research to investigate the biocontrol potentials of thrips by combined applications of predatory mites Neoseiulus barkeri and Stratiolaelaps scimitus as well as entomogenous fungus Beauveria bassiana in Kuanzhuang county of Kunming City in Yunnan Province. The results showed that the application of three biocontrol agents had positive effect on thrips control, as the control effect was up to 100% in 7 days. Predatory mites have a stable and sustained control effect on the thrips nymphs, when the control effect reached to 50% in 3 days and 100% in 5 days in combination with B. bassiana. The living thrips could not be detected in the tobacco field after 15 days of the treatments. Therefore, our study has provided a reference for the sound and sustainable control of thrips in tobacco.

Key words: biological control, tobacco, thrips, predatory mite, entomopathogenic fungus