Habitat requirements of Tetanocera elata (Diptera: Sciomyzidae): case study of a dry meadow in western Ireland

Terrestrial slugs are pervasive pests of agriculture throughout temperate regions and have the potential to disrupt the germination of seedlings, cause damage to fruiting bodies of crops, and vector plant pathogens. Tetanocera elata Fabricius (Diptera: Sciomyzidae), a widely distributed Palaearctic species, is an obligate mesoparasitoid and predator of pestiferous slugs including Deroceras reticulatum Müller (Stylommatophora: Agriolimacidae). It has the potential to be developed as a native natural enemy in a conservation biological control programme as an alternative to chemical molluscicides. To better understand the ecological requirements of this species, a detailed observational study was conducted at a site in the west of Ireland possessing naturally occurring T. elata populations. Comparison of local patches where T. elata were recovered revealed no association with plant community composition. Taller dead vegetation was associated with T. elata presence throughout the site. Within the area of greatest T. elata aggregation, there was a significantly greater percentage cover of dead vegetation where T. elata occurred. Abundance of T. elata was also significantly correlated to hedgerow proximity. Results of this study are directly applicable for the design of a conservation biological control programme, which effectively satisfies the principal habitat requirements of T. elata populations.