Fermenting Bread Dough as a Cheap, Effective, Nontoxic, and Generic Attractant for Pest Snails and Slugs

SIMPLE SUMMARY: Snails and slugs are key pests of crops but control options are limited with an overreliance on molluscicides, which have variable efficacy. Thus, there is an urgent need to improve the performance of these pesticides, and one option is to identify more efficacious attractants for incorporation into baits and/or use in traps. Our results showed that a simple bread dough (flour, water, and yeast) was highly attractive to six invasive pest gastropod species in both laboratory and field trials in Hawaii, Oregon, and Montana. The dough remained attractive for at least 8 days and was significantly more attractive than a widely used toxic bait (Deadline(®) M-Ps™). Given its simplicity, low cost, and the ready availability of its ingredients, the dough has potential to be used in developing countries where access to commercial molluscicides is limited by cost. In addition, a premixed dry formulation of flour and yeast, where water simply needs to be added to activate the bait, would likely have an indefinite shelf life and be readily shippable, both highly desirable properties for an operational lure. Thus, bread dough constitutes a nontoxic, generic, and effective tool that could be used in the detection and management of pest gastropods worldwide. ABSTRACT: Invasive slugs and snails are among the most damaging pests of agriculture in temperate and tropical regions of the world. Control options, however, are limited and there is a heavy reliance on chemical molluscicides of variable efficacy. There is an ongoing need to improve management methods. Here, we show that a simple fermenting bread dough formulation (flour, water, and yeast) was effective in attracting pest mollusk species in laboratory tests, and in multiple replicated field trials in Hawaii, Oregon, and Montana. The dough attracted substantially more terrestrial pest gastropods, including invasive species of major economic importance such as Cornu aspersum, Deroceras reticulatum, Ambigolimax valentianus, Xerolenta obvia, Lissachatina fulica, and Parmarion martensi, than water controls. The dough remained attractive for at least 8 days and was significantly more attractive than a widely used metaldehyde-based bait, Deadline(®) M-Ps™. Thus, fermenting bread dough represents a nontoxic, generic, and effective tool to aid in managing pest gastropod infestations, either using baited traps or in attract-and-kill approaches. Given its simplicity, low cost, and the ready availability of its ingredients, the dough also has potential to be used in developing countries where access to commercial molluscicide baits is limited by cost.