Potential of 3-octanone as a lure and kill agent for control of the Brown garden snail

The brown garden snail (Cornu aspersum) is a major agricultural pest, causing damage to a wide range of economically important crops. Withdrawal or restricted use of pollutant molluscicides like metaldehyde has prompted a search for more benign control products. This study investigated the response of snails to 3-octanone; a volatile organic compound (VOCs) produced by the insect pathogenic fungus Metarhizium brunneum. Concentrations of 1 - 1000 ppm of 3-octanone were first assessed in laboratory choice assays to determine behavioural response. Repellent activity was found at 1000 ppm whereas attractance was found for the lower concentrations of 1, 10 and 100 ppm. These three concentrations of 3-octanone were carried forward in field evaluations to assess potential for use in "lure and kill" strategies. The highest concentration (100 ppm) was the most attractive to the snails but also the most lethal. Even at the lowest concentration this compound proved toxic effects making 3-octanone an excellent candidate for the development as a snail attractant and molluscicide.