Improvement of the Catch Efficiency of the Apple Snail, Pomacea canaliculata (Lamarck) (Gastropoda : Ampullariidae) by the Trap Crop

Abstract

We compared the efficiency of catching the apple snail by hand with and without trap crops. Except in the paddy rice field where there were few snails, it took over two hours per 10a to handpick the snails when a trap crop was not used. In the longest case, it took about 536 minutes per 10a. The number of snails hand picked without a trap crops was only 68.3% of the total number of snails caught. The number of snails after the first hand picking was above the control threshold for the apple snail in transplanting rice. Hand picking had to be repeated three more times to reduce the number of snails below the control threshold.
In contrast, when there were trap crops in the paddy field, it took 418 minutes per 10a to catch the snails. The number of snails remaining was much smaller than the control threshold. When trap crops were placed around a paddy field, the number of snails remaining in the paddy field after repeated picking 13 times was under the control threshold, and it took about 116 minutes per 10a. These results suggested that this method of handpicking using trap crops was easy and most efficient.