2001 Volume 47 Pages 58-64
The apple snail, Pomacea canaliculata (Gastropoda: Ampullariidae). which was introduced as human food from South America about twenty years ago, is now a threat to the spread of direct-sown rice in Kyushu, southern Japan. We studied chemical control of the apple snail in two direct-sown rice fields. An application of metaldehyde pellets after sowing successfully suppressed damage to rice by apple snails, when used in conjunction with 13 or 18 days' drainage after sowing in both light and heavy rain. About 90% of snails were killed by the application of metaldehyde. One or two applications of granular iprobenfos (IBP) after sowing also suppressed damage at low snail density or in light rain. However, damage to rice occurred in heavy rain even with two IBP applications. The mortality of snails in the IBP-treated fields varied from 0% to 69%, probably depending on the rain. Thus, TBP application is not practical in direct-sown rice fields, because it often rains heavily in the sowing season in Kyushu. Metaldehyde is not yet registered as a paddy chemical in Japan, but registration is expected soon.
