Experiments of parasitism of Scleroderma nipponica Yuasa on the Japanese cedar sawyer, Semanotus japonicus Lacordaire, and the Japanese pine sawyer, Monochamus alternatus Hope

Abstract

The following 2 experiments were conducted to investigate the parastism of S. nipponica on S. japonicus and M. alternatus. 1. Experiment in the field cages: The cedar and pine bolts infested with S. japonicus and M. alternatus were set in the field cages. The adults of the parasitoid were released into the field cages. 2. Experiment in the stand: The adults of the parasitoid were released on the bark of the standing trees, which had been infested with S. japonicus and M. alternatus. The percentage parasitism on S. japonicus was 91% in Experiment 1, but that was only 10% in Experiment 2. The percentage of the empty pupal chambers of M. alternatus was 85% in Experiment 1, but that was 35% in Experiment 2.