• Korean journal of applied entomology
• /
• v.41 no.1
• /
• pp.27-32
• /
• 2002

Biological control of thrips with a predatory bug species, Orius sauteri Poppius, was evaluated in an eggplant greenhouse, To study the biological control strategy of thrips. three Plots were established: Orius sauteri released plot without pesticide treatment (NRT), pesticide treated plot (PAT), and natural enemy removed plot (RNT) The nymphs of O. sauteri were found on the upper side of leaves in NRT at 21 days after the first release of O. sauteri. The density of thrips were dropped and maintained at lower level in NRT than in RNT. Average damage index of NRT, PAT and RNT was 1.35, 1.21 and 2.90 and the percentage of damaged fruit ratio of those was 70.3, 68.6 and 99.0%, respectively. The damage index and percentage of damaged fruit in NRT were slightly higher than those of PAT, but much lower than in RNT. Taylor's band Iwao's $\beta$ were greater than 1 for both populations. indicating aggregated distribution. Spatial coincidence index of O. sauteri was high most of the time even at low densities of both populations. The refuge index for thrips decreased as O. sauteri density increased. Results of this study suggest that O. sauteri is a promising natural enemy for thrips control on eggplant.