The first commercial bioinsecticide in Korea was registered in 2003 to control diamond back moth and beet armyworm in Chinese cabbage using Bacillus thuringiensis subsp. aizawai. Currently, fourteen microbial pesticides have registered in Korean market. The Korean government is aiming for 40% reduction (from the 2004 value) in the use of chemical pesticides by 2013. To increase the use of microbial pesticides as an alternative of chemicals, we conducted in vitro bioassay with Bt products. Bt products were treated alone and in combination against larvae of beet armyworm, diamond back moth and tobacco cutworm. Five Bt products shown high mortality against diamond back moth in recommended concentration, but had low control effects against beet armyworm and tobacco cutworm. Mixed Bt products had no synergic effects against the tested three moths. When Bt products were sprayed with higher concentration than recommended dose, those mortality was similar with lower concentration.

• Jeong Jun Kim(Agricultural Microbiology Team, NAAS, RDA)
• Hong Zhu(Agricultural Microbiology Team, NAAS, RDA)
• Heo Seon(Agricultural Microbiology Team, NAAS, RDA)
• Yujin Song(Agricultural Microbiology Team, NAAS, RDA)
• Sang Guei Lee(Division of Crop Protection, NAAS, RDA)