title: Slug control in Australian canola: monitoring, molluscicidal baits and economic thresholds.
abstract: Exotic slugs have become serious pests of canola, at establishment, in Southern Australian high-rainfall cropping zones. Slugs were monitored using relatively inexpensive 300 mm x 300 mm terracotta tiles acting as refuges. An investigation was made of the effects of the time of application of chelated iron baits on the slug species Deroceras reticulatum Müller and Lehmannia nyctelia Bourguignat. Baits reduced the number of surface-active slug species. A single application at sowing provided greater efficacy than one application before sowing, and efficacy was comparable with that of two applications. Canola seedling densities showed a negative response to D. reticulatum numbers; the presence of even one individual per refuge trap reduced seedling numbers below optimum densities. Thistles and other vegetation were associated with increased numbers of slugs. European guidelines for slug monitoring and damage appear to be at least partly applicable to Australian conditions.
authors.affiliation: Centre for Environmental Stress and Adaptation Research, Department of Zoology, University of Melbourne, Parkville, Victoria 3010, Australia. m.nash3@pgrad.unimelb.edu.au
authors.forename: Michael A
authors.initials: MA
authors.lastname: Nash
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Thomson
authors.forename: Ary A
authors.initials: AA
authors.lastname: Hoffmann
mesh_terms: D000818:Animals; D029688:Brassica napus / Q000254:growth & development*; D049851:Gastropoda; D007501:Iron; D008975:Molluscacides; D010571:Pest Control; D011156:Population Density; D036226:Seedlings / Q000254:growth & development; D013021:South Australia
chemical_list: D008975:Molluscacides; D007501:Iron