2006 Volume 12 Pages 403-408
An ecological network has been proposed as a way to keep species populations in good condition. This study examined Stylurus nagoyanus, which lives near the Shinano River in the imago stage and under the water surface in the larva stage. We focused on emergence and examined a method to keep the population healthy.
First, we divided the lower portion of the Shinano River into sections and monitored the number of S. nagoyanus in each section for 9 years. Then, we examined the relationship between water temperature and the population of S. nagoyanus. In addition, we examined the relationship between maintenance of the Yasuragi-tei bank and the number of S. nagoyanus per unit river length. Finally, we investigated the effects of pins stuck in the bank on emergence.
We found that water temperature, water discharge, and maintenance of the Yasuragi-tei bank all affected emergence, and that the pins had a good effect on emergence.
