The behavioural response of slugs and snails to novel molluscicides, irritants and repellents

Abstract

The behavioural response of the slug Deroceras panormitanum (Lessona and Pollonera) and the snail Oxyloma pfeifferi (Rossmässler) to novel molluscicides was investigated in choice and no-choice experiments. Low-light video-recording in combination with automated tracking and event recording was used to identify the repellent and irritant effects of (1) cinnamamide, (2) copper ammonium carbonate, (3) a mulch, (4) a horticultural ground-cover matting impregnated with a copper formulation and (5) urea/formaldehyde. In the no-choice experiments the products had a stronger irritant effect on the snails than on the slugs. All products tested except the mulch significantly reduced the locomotor activity of both the slugs and snails. The most effective product, cinnamamide, reduced snail locomotor activity by 94% and track length by 96%. The overall repellent effect of the treatments in the choice experiments was stronger in the slugs; where presence, locomotor activity and track length in the treated area were significantly reduced by all products. The avoidance of treated areas exceeded 95% with the mulch (for slugs) and with copper ammonium carbonate (for snails).

Can Copper‐Based Substrates Be Used to Protect Hatcheries from Invasion by the New Zealand Mudsnail?

“…The NZMS lack of a strong avoidance to copper differs from the responses of terrestrial slugs and snails observed in other studies (i.e., Schüder 2003;Schüder 2004). …”

“…Copper and copper-based materials are used in a variety of situations to control unwanted or invasive aquatic organisms including aquatic snails in aquaculture ponds (e.g., Planorbella trivolvis) (Wise et al 2006). In the terrestrial environment, contact barriers composed of copper substrates can be used to protect ornamental plants from damage by snails and slugs by limiting the locomotor activity of these organisms (Schüder et al 2003;Schüder et al 2004). However, a review of the literature found no instances where contact deterrents were applied in aquatic environments.…”

Efficacy of non‐toxic surfaces to reduce bioadhesion in terrestrial gastropods

“…One gastropod can consume up to 5 g of vegetation daily, and, with the potential for high densities (up to 200 m −2 ), many gastropods are considered quarantine species 20. Terrestrial snails can enter a state of dormancy, called aestivation, in which they attach firmly to surfaces at the shell aperture; this facilitates transport to new geographical regions, having implications for agricultural crops, threatened native flora20, 21 and the potential spread of pathogens that use gastropods as intermediate hosts 22…”

Preliminary Tests of Responses of New Zealand Mudsnails Potamopyrgus antipodarum to Copper‐Based Substrates

“…The use of copper or copper-based 328 MYRICK AND CONLIN substrates as deterrents is another potential option for preventing the upstream movement of NZMSs. Copper and copper-based compounds have been tested and used as barriers to various terrestrial slugs and snails (Schüder et al 2004), but to date there have been no published studies on the use of copper for creating barriers to aquatic snail movement. Studies on terrestrial gastropods have demonstrated that copper strips can reduce or eliminate slug and snail movements even in the presence of a food stimulus.…”

“…The second experiment compared the effects of surface treatment type on the maximum distance traveled by NZMSs when no untreated refuge area was present. We hypothesized that NZMSs would travel farther on the untreated control surfaces than on surfaces treated with copper-based compounds because past studies of terrestrial snails (see Schüder et al 2004) have reported reduced movements on copper.…”