利用稻田养萍诱集控制福寿螺危害的效应研究

Decoy effect of duckweed Lemna minor on Pomacea canaliculata in rice from paddy fields

利用自制的"T形槽"进行实验室试验,研究了福寿螺(Pomacea canaliculata)对浮萍(Lemna minor)和不同日龄水稻(Oryza sativa)的偏好选择,结果发现,无论水稻日龄是15 d,还是23 d和30 d,均有60%以上的福寿螺选择取食浮萍,且与福寿螺个体大小和选择取食的时间没有明显关联。在模拟稻田生境中,引入浮萍3 d后,水稻受福寿螺的啃食危害明显减少,水稻存活率高出对照组10%以上,且30日龄水稻秧苗的存活率明显高于15日龄处理。在此基础上,分析了不同大小福寿螺与浮萍摄入量的关系。这一结果可为浮萍的合理投放提供参考。研究表明,利用稻田放养浮萍诱集福寿螺取食,可以减少福寿螺对水稻的危害。

In this paper, a T-maze was used to observe the preference of Pomacea canaliculata between duckweed （Lemna minor） and rice （Oryza sativa） plants of different ages. The results revealed that more than 60 percent of snails preferred to feed on L. minor, whenever the rice plants were 15, 23 or 30 days old. This pattern was not clearly associated with the individual size and treatment time ofP. canaliculata. In a simulated paddy habitat, the amount of rice eaten and damaged by the snails significantly decreased after the duckweed was introduced for 3 days, the survival rate of rice plants exceeded that of the control by 10 percent; the survival of 30-day-old rice plants was clearly higher than that of the 15-day-old rice plants. Moreover, the relation of individual size of P. canaliculata and its ingestion rate of L. minor was statistically analyzed, as it may offer a reference for the calculation of the required duckweed supply. This study showed that L. minor has a decoy effect on P canaliculata, which in turn may reduce the snails＇ harm to rice plants.