Distribution of apple snails, related to rice field distribution and water flow.

概要

論文の詳細を見る
During the two decades since the apple snail, Pomacea canaliculata (Lamarck), was first introduced into Kyushu island, southern Japan. few studies of the geographic distribution of the snail have been made. We studied the distribution and densities of the snail in rice fields along four rivers, Kikuchi, Koshi, Hazama, and Uchida at altitudes ranging from 30 to 400 m. Snails were abundant up to 100 m in altitude, but few or no snails occurred above that. The limit of snail distribution corresponded to the lowest location where rice fields became discontinuous. There are small water falls near this limit on all rivers, and the water flow can be faster there. Hence, the snail could not expand its distribution to upper areas because of the discontinuity of rice fields and the faster water flow. Artificial snail introduction was reported in some upper areas, where the snail could attain higher increase rates.
九州病害虫研究会の論文