Abstract
Simple SummaryThe Grey Field Slug, Deroceras reticulatum (Müller), is a common crop pest worldwide. To control slugs, chemicals, such as metaldehyde are incorporated into pellets which are toxic to slugs when consumed. Our aim was to compare slug feeding on new pellet types with those already commercially available. Novel pellet types included silica-coated commercial metaldehyde pellets where metaldehyde is released more slowly. An audio sensor was used to record the individual slugs feeding on a variety of pellet types, including toxic (metaldehyde and ferric phosphate) and non-toxic (cereal) pellets. Two types of experiment were conducted: shorter laboratory trials and longer arena trials. The length of each bite and the total number of bites were recorded. There was no difference in the length of the 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.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.
Highlights
Agricultural and horticultural industries are keen to manage pest slug species, mostly to prevent yield loss and due to marketing standards for produce to be “practically free from pests . . . [and] from damage caused by pests” [1]
The lower acceptance of toxic pellets observed in laboratory trials differed with the literature where slugs were reported to nearly always accept the pellet regardless of molluscicide presence [34]
A dummy pellet is one that would be offered to a slug before entering the trial to test a willingness to feed, with only slugs willing to feed on the dummy pellet entering the trial
Summary
Agricultural and horticultural industries are keen to manage pest slug species, mostly to prevent yield loss and due to marketing standards for produce to be “practically free from pests . . . [and] from damage caused by pests” [1]. Growers usually employ a variety of methods to limit slug damage to crops, the most prevalent being the application of metaldehyde pellets [2]. Poor application or rainfall events can cause metaldehyde to leach from the pellets into the water system where it is difficult and expensive to remove [4,5,6]. Metaldehyde has consistently been the main cause for failure to achieve European Union drinking water standards of 0.1 μg L−1 for individual pesticides and 0.5 μg L−1 for total pesticides [7,8]. By March 2022, metaldehyde slug pellets will be withdrawn from widespread use in the UK, but they are still in use globally [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
