Abstract

The marsh slug, Deroceras laeve (Müller), is a generalist pest of agricultural crops. Slugs are mainly managed with synthetic pesticides that can also have high toxicity toward vertebrates and nontarget arthropods. Besides, they are not labeled for use in organic crop systems. Bordeaux mixture (BM) is an alternative product often used in organic crops for controlling plant diseases. The molluscicidal activity of BM has been reported; however, to our knowledge, no study has determined its efficacy to control D. laeve. This study aimed to determine the lethal (concentration- and time–mortality curves, and foliar persistence) and antifeedant (reduction in leaf consumption) effects of BM-treated cabbage leaves on D. laeve. The LC₅₀ of BM was 28.15%, and the LT₅₀ was 8.83 h. The BM LC₂₅ reduced D. laeve leaf consumption by 3.31-fold. Furthermore, high control effectiveness (mortality > 90%) was attained until the 7^th day after spraying. These findings reveal that BM reduces damage by killing D. laeve in a fast faction and by reducing foliar consumption. Therefore, BM can be an alternative to D. laeve management in both conventional and organic systems.

摘要

沼泽Deroceras laeve（Müller）是一种农作物的综合害虫。主要由合成农药处理，这些合成农药对脊椎动物和非目标节肢动物也具有高毒性。此外，它们没有被标记为用于有机作物系统。波尔多混合物（BM）是有机作物中常用于控制植物病害的替代产品。已有报道称BM具有杀软体动物活性。然而，据我们所知，尚无研究确定其控制D. laeve的功效。这项研究旨在确定经BM处理的白菜叶片对D. laeve的致死作用（浓度和时间死亡率曲线，以及叶面持久性）和拒食剂（减少叶片消耗）。LC ₅₀BM值为28.15％，LT ₅₀为8.83小时。BM LC ₂₅将D.laeve叶片的消耗量减少了3.31倍。此外，高的控制效果（死亡率> 90％）直至达到7^个天喷洒后。这些发现表明，BM通过杀死快速派系中的D. laeve和减少叶面消耗来减少伤害。因此，在常规系统和有机系统中，BM均可替代D. laeve管理。