Abstract:

Objective　Several kinds of food are preferably palatable to Oncomelania hupensis. The most effective food?based attractants were identified in this study, and the application of these attractants in molluscicidal pellets was evaluated.  Methods　The attracting effects of the mixture of Sedum sarmentosum leaves (food M), and fermented cornstarch (food C) were compared under various environmental conditions with different humidity and light levels. The two were combined with the water extract of Gynostemma pentaphyllum, a molluscicidal plant, to produce molluscicidal pellets, respectively, for experiment on the snail killing effects.  Results　Statistically significant differences were shown in the attracting effects of different food attractants on O. hupensis under room temperature (25 ℃).  The attracting effects were greatly humidity?dependent, as the ones under an 80% relative humidity were stronger than those under a 40% relative humidity. The multi?factor analysis of variance showed that humidity (F1，64＝60.209, P＜0.001), snail food (F3，64＝344.820, P＜0.001) and time (F3，64＝724.429, P＜0.001) had substantial impact on the attracting  effects. The  attracting  effect  of  snail  food  M  was greater than that of snail food C.  Light had little influence on attracting O. hupensis.  The molluscicidal pellets made of food M and C increased the 7 d snail mortality rates by 42.68% and 30.00% as compared  to  the  control  and  experimental  groups, respectively.  Conclusion　Food M had a relatively stronger attracting effect on O. hupensis under 25 ℃ and 80% relative humidity; when added in molluscicidal agents, it greatly increased the snail mortality.

Key words: Oncomelania hupensis, Snail food, Stringy stonecrop, Molluscicidal pellet, Attracting effect on snails

摘要：

目的　利用钉螺对某些食物具有的趋向性和嗜食性，筛选出诱集钉螺效果较好的食物引诱物，并探讨其在颗粒灭螺剂中的作用。方法　比较垂盆草混合物（食物C）和面粉发酵物（食物M）在不同湿度、光照等环境条件下的诱螺效果，并将它们分别与灭螺植物绞股蓝水提物配伍制成颗粒灭螺剂进行灭螺实验。结果　在室温（25 ℃）条件下，不同钉螺食物的诱螺率差异有统计学意义。湿度对诱集钉螺影响较大，80%湿度比40%要好，多因素方差分析表明：湿度（F1，64＝60.209，P＜0.001）、钉螺食物（F3，64＝344.820，P＜0.001）和时间（F3，64＝724.429，P＜0.001）对诱螺率均有显著影响，钉螺食物M＞钉螺食物C。光照对诱集钉螺影响较小。用钉螺食物M和C分别制成颗粒灭螺剂诱杀钉螺，7 d钉螺死亡率与对照组、实验组相比分别提高了42.68%和30.00%。结论　在25 ℃、80%湿度条件下，钉螺食物M诱螺效果较好，将其添加到灭螺药物中，能大大提高钉螺的死亡率。

关键词: 钉螺, 钉螺食物, 垂盆草, 颗粒灭螺剂, 诱螺效果