Restrictions on the use of synthetic molluscicides highlight the importance of developing
alternative control methods. Nevertheless, biocontrol agents can be costlier and less effective
than synthetic counterparts. One mean of increasing the efficacy of population suppression is to
combine inundative biological control with habitat ...
Restrictions on the use of synthetic molluscicides highlight the importance of developing
alternative control methods. Nevertheless, biocontrol agents can be costlier and less effective
than synthetic counterparts. One mean of increasing the efficacy of population suppression is to
combine inundative biological control with habitat management to reduce population growth of
target pests. Vineyards in the cool, wet climate of western England can suffer from outbreak
densities of mollusc pests that damage expanding shoots, developing grapes and promote the
transmission of fungal pathogens. In this study we combined the biocontrol agent Nemaslug -
Phasmarhabditis hermaphrodita (Schneider) -with a simple habitat management approach
(regular mowing) to suppress mollusc pests in vineyards in South Western England. Two sites
were treated with NemaSlug and or mowing in a factorial design in early spring coinciding with
bud burst and the start of mollusc growth and feeding. Mowing was effective management and
resulted in the reduction of slug and snail populations and significantly less damaged vines.
Nemaslug did not reduce slug numbers overall but did reduce bud damage, snail numbers and
lowered the proportion of sucsceptible Deroceras spp in treated plot. However, effect sizes of
nematode biocontrol were small, potentially because this product could not be applied to bare
soil. Management practice for cool climate vineyards varies considerably from site to site. This
study shows the value of simple habitat management for controlling a novel target and
emphasizes how consideration of pest biology can lead to effective alternatives.