Tracking the role of generalist predators in biological control of slugs in strawberry crops
Michael J Eskelson, firstname.lastname@example.org, James D. Harwood, email@example.com, John J. Obrycki, firstname.lastname@example.org, and Doulgas D. Archbold, email@example.com. (1) University of Kentucky, Department of Entomology, S-225 Agricultural Science Center North, Lexington, KY, (2) University of Kentucky, Department of Horticulture, N-308C Agricultural Sciences-North, Lexington, KY
A central question in biological control is whether generalist predators play a significant role in pest management. The enhancement of prey biodiversity through habitat manipulation can enhance predator populations but alternative sources of food can divert predators from feeding on target pests. This study investigates the relationship between generalist predators and slugs in strawberry crops, and identifies the role of detrital subsidies on management of pest populations. Carabid beetles and spiders feed on terrestrial mollusks, although little is known with regard to the native North American fauna feeding on these invasive pests. Laboratory feeding trials were therefore conducted to examine their capacity at feeding on slugs. In addition, the interactions between slugs and generalist predators within strawberry agroecosystems were studied. Weekly population monitoring was undertaken using pitfall traps, defined-area traps and surface-traps within strawberry crops. Two replicated treatments were used, organic hardwood mulch and traditional plantings with no mulch; each treatment was replicated 5 times. Although plastic mulching is used for weed control in strawberry production, many pests are enhanced due to increased temperature. Conversely, detrital subsidies can enhance predator populations which translate into improved pest regulation. The defined-area and surface-traps monitored changes in the structure of slug populations; pitfall traps monitored activity-density of generalist predators and identified those species capable of exerting pressure on the invasive slug fauna. Results document both spatial and temporal variability in prey availability, pest densities and predator biodiversity. The role of detrital subsidies as an aid for slug biological control is discussed.
Species 1: Coleoptera Carabidae Harplauspennsylavanicus Species 2: Stylommatophora Limacidae Derocesaslaeve Species 3: Stylommatophora Limacidae Derocesasreticulatum