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Tetanocera elata (Diptera: Sciomyzidae) Larvae Feed on Protected Slug Species Geomalacus maculosus (Gastropoda: Arionidae): First Record of Predation

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The Family Sciomyzidae (Diptera) is one of the best studied groups of malacophagous insects containing some of the most important enemies of slugs. Larvae of the fly Tetanocera elata are known obligate feeders on slugs both as parasitoids and predators. We tested whether predatory larvae of T. elata can feed on the protected slug species Geomalacus maculosus, for which there appear to be no published records of natural enemies. Using an infra-red video camera, we recorded the behaviour of third instar T. elata in the presence of: 1) a single specimen of G. maculosus and 2) one specimen each of G. maculosus and Deroceras reticulatum, a known slug prey of T. elata. We describe the behaviour of the larvae where they killed and consumed G. maculosus and D. reticulatum in experiments 1 and 2 respectively. Since T. elata has been suggested as a potential biocontrol agent of pestiferous slugs, the possibility of predation on the protected species G. maculosus is discussed from this perspective.

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Thanks are due to the National Parks and Wildlife Services (NPWS) (Ireland) for issuing the License to Capture/Kill Protected Wild Animals for Educational or Scientific Purposes. Dr Kate McAney provided the infrared digital camera used in this project. The research was founded by a National University of Ireland Galway College of Science Scholarship.

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Correspondence to Irene Giordani.

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Giordani, I., Hynes, T., Reich, I. et al. Tetanocera elata (Diptera: Sciomyzidae) Larvae Feed on Protected Slug Species Geomalacus maculosus (Gastropoda: Arionidae): First Record of Predation. J Insect Behav 27, 652–656 (2014).

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