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

Influence of aromatic substances on locomotor activity of Deroceras agreste slugs

The global climate changes are causing an increase in the number and harmfulness of slugs. Deroceras agreste (Linnaeus, 1758) (Stylommatophora, Agriolimacidae) is a polyphagous phytophage that damages over 150 species of plants, including many vegetables, cultivated berries and grasses. Other than decrease in yield, slugs cause deterioration of consumer qualities of the products, promote infections of plants, and are intermediate hosts of some parasites of mammals and birds. Thus, slugs impose great losses on agricultural farming, and therefore the objective of our study was determining the variability of locomotor activity of D. agreste slugs in reaction to aromatic substances. We determined repellent or attractive effects of those substances for the purpose of further using the obtained data for plant protection. We tested 52 substances and their mixtures, which were conditionally divided into the following groups: chemical solvents, plant extracts, aromatizers, organic acids and synthetic cosmetic additives. Only dimethyl sulfoxide could be identified as an attractant. All the rest of the substances increased the speed of the slugs to various degrees, but had no significant effect on the direction of the animals’ movement. Gasoline increased the speed of the slugs’ movement by 3.20 times, xylene by 4.56. The most effective organic acids and aromatizers to increase the moving speed of slugs were avobenzone and formic acid: the first caused a 2.83-fold increase in the moving speed, the other a 3.16-fold increase. Only one of 13 aromatic substances changed the direction of the slugs’ movement during the experiment – β-ionone. As with the plant extracts, the highest effect on locomotor activity of slugs was exerted by tree bark of Quillaja saponaria (3.64-fold) and Aesculus hippocastanum extract (4.33-fold). Furthermore, together with Capsicum frutescens, they changed the direction the mollusks were moving in, and therefore could be used as repellents. Synthetic cosmetic additives hydrolyzed silk and chrysalide oil exerted the greatest effects on the lcomotor activity of slugs (3.16 and 3.20 times, respectively). A total of 78.6% of the slugs moved away from chrysalide oil, and thus this oil may be suggested as a repellent, as well as mousse de babassu and cocamidopropyl betaine (84.6% and 78.6%, respectively). Therefore, a large amount of the tested substances to one or another extent made the slugs move faster, but most of them did not alter the direction in which the slugs were moving.

Bioactive Modified Non-Wovens as a Novel Approach of Plants Protection against Invasive Slugs

Invasive slugs generate significant problems in the area of horticultural and agricultural production. Despite the multitude of methods to reduce the pest population, including preventive, mechanical, agrotechnical, cultivation, biological, and chemical treatments, no effective plant protection strategy has been developed so far. In this paper, a solution based on modified non-woven fabric with bioactive molluscicidal properties using the extract of tansy flower, metaldehyde, and abamectin (Vertigo^® 018 EC) was proposed. All modified mats show significant anti-slug properties in comparison to control, and molluscicidal properties depend on the type of active substance. Non-woven modified with commonly used metaldehyde demonstrated fast action against slugs and presents the highest efficiency. The effectiveness of non-woven mats with Vertigo^® 018 EC is lower than for the mats with metaldehyde but higher than for the mats modified with tansy flower extract. The proposed solution will enable removing and neutralization of molluscicide from the fields, after the efficient pest control, according to circular economy principles. Moreover, it may allow for better control of the molluscicide release to the environment in comparison to widely used pellets, and contribute to the virtual protection of plants against invasive slugs.

Listening to Slugs: Acceptability and Consumption of Molluscicide Pellets by the Grey Field Slug, Deroceras reticulatum

Gastropod damage to crop plants has a significant economic impact on agricultural and horticultural industries worldwide, with the Grey Field Slug (Deroceras reticulatum (Müller)) considered the main mollusc pest in the United Kingdom and in many other temperate areas. The prevailing form of crop protection is pellets containing the active ingredient, metaldehyde. Metaldehyde can cause paralysis and death in the mollusc, depending on the amount ingested. The paralysing effects may result in reduced pellet consumption. A greater understanding of metaldehyde consumption may reveal an area that can be manipulated using novel molluscicide formulations. Novel pellet types included commercial metaldehyde pellets coated so that metaldehyde is released more slowly. In both laboratory and arena trials, an audio sensor was used to record individual slugs feeding on a variety of pellet types, including commercially available toxic pellets (metaldehyde and ferric phosphate) and novel metaldehyde formulations. The sensor was used to record the length of each bite and the total number of bites. There was no significant difference in the length of bites between pellet types in laboratory trials. Novel pellets were not consumed more than commercial pellet types. Commercial pellet types did not differ in consumption.