2005 Volume 49 Issue 1 Pages 26-29
We investigated the effectiveness of three methods of release (“bottle settling”, “bottle hanging” and “tube insertion”) of aphids mummified by Diaeretiella rapae (mummies) against pest aphids in a greenhouse for growing komatsuna Brassica rapa nothovar. Plastic bottles with mummies were set in the passage for “bottle settling” and were set in paper cups hanging from the ceiling for “bottle hanging”, and small plastic tubes with mummies were inserted directly into the ground near the crop for “tube insertion”. Since the percentage of adult emergence of D. rapae from released mummies was low in some cases for “bottle settling” (50–61%) and “bottle hanging” (14–43%), probably because of exposure to water and sunlight, the original equipment for release of the three methods was improved to protect mummies from water and sunlight. The percentages of adult emergence of D. rapae were high in all of the improved equipment (93–96%), and were equivalent to those obtained in the laboratory (87–99%). We discuss the most useful method for komatsuna-growing greenhouses.
