自走式蒸気処理防除機を利用した過熱水蒸気処理によるスクミリンゴガイ（原始紐舌目：リンゴガイ科）の防除

抄録

We investigated application of superheated steam treatment for controlling overwintering apple snail Pomacea canaliculata （Lamarck） in post-harvest paddy fields. Vertical distribution of the snails in the soil showed that the majority （49%–93%） inhabit surface soil or shallow underground soil above 2 cm depth. Using a mobile steam chamber machine that blows out superheated steam, we measured increase in soil temperatures and the subsequent mortalities of the snail that were experimentally placed at different soil depths. Snails on the soil surface were effectively killed by exposure to superheated steam. When the machine was run at a speed of 0.5 km/h, the-soil temperature attained a maximum 91.5°C which caused 100% mortality of P. canaliculata on the soil surface and 23% mortality of snails buried at 2 cm depth. In the farmers’ field trials, the superheated steam treatment conducted during winter successfully reduced snail density and rice damage by snails in early summer after rice planting. These results show the effectiveness of superheated steam treatment using a mobile steam chamber machine for controlling overwintering P. canaliculata.