Pesticidi i Fitomedicina (Jan 2008)
Laboratory Tests for Group and Individual Exposures of Arion lusitanicus Mabille Slugs to Different Molluscicide Baits
Abstract
Molluscicide baits based on different active ingredients were tested in a seven-day laboratory trial on juveniles and young adults of Arion lusitanicus Mabille slug collected in ruderal sites during June and July of 2008. Before setting the trial, the slugs were adapted to laboratory conditions. The testing was conducted using a modified version of the method proposed by Godan (1983) and Wiktor (1989). The slugs were kept in arenas under controlled conditions (20-24oC temperature, 80-90% relative air humidity, no air stream, diffuse daylight). Smaller(15.5 x 15.5 x 7 cm) and larger (28 x 17.5 x 7 cm) arenas were used, depending on slug numbers, and different rates of food and bait were administered. Plastic boxes with perforated coverage, lined with multi-ply paper moistened on a daily basis, were used as arenas. The slugs were fed on fresh salad daily, while baits were administered in open 35 mm petri dishes once for the duration of experiment. The first trial involved single-slug exposures to bait in 20 arenas per each of four treatments with two replicates and a total of 160 slugs. The second trial, group exposure, involved four treatments of five slugs per arena in six replicates with a total of 120 slugs. The products Arion and Pužomor demonstrated the highest efficacy (77.5%) in the single-slug trial. The average efficacy of the product Carakol after seven days of exposure was 60.0%. Regarding group exposure, Pužomor pellets achieved 79.3% efficacy after three days and this efficacy rate remained for the rest of the experiment. On the seventh day ofexposure, Arion and Carakol had 33.3% and 40.0% efficacy, respectively.
