Drilus beetle larvae (Coleoptera: Elateridae) are specialized predators of land snails. Here, we describe various aspects of the predator-prey interactions between multiple Drilus species attacking multiple Albinaria (Gastropoda: Clausiliidae) species in Greece. We observe that Drilus species may be facultative or obligate Albinaria-specialists. We map geographically varying predation rates in Crete, where on average 24% of empty shells carry fatal Drilus bore holes. We also provide first-hand observations and video-footage of prey entry and exit strategies of the Drilus larvae, and evaluate the potential mutual evolutionary impacts. We find limited evidence for an effect of shell features and snail behavioral traits on inter- and intra-specifically differing predation rates. We also find that Drilus predators adjust their predation behavior based on specific shell traits of the prey. In conclusion, we suggest that, with these baseline data, this interesting predator-prey system will be available for further, detailed more evolutionary ecology studies.

Centre for Ecological and Evolutionary Studies Rijksuniversiteit Groningen Groningen The Netherlands; Department of Animal Ecology and Tropical Biology University of Würzburg Würzburg Germany

Department of Biology University of Patras Rio Greece

Department of Zoology Palacky University Olomouc Czech Republic

Focus Group Character Evolution Naturalis Biodiversity Center Leiden The Netherlands

Focus Group Character Evolution Naturalis Biodiversity Center Leiden The Netherlands; Centre for Ecological and Evolutionary Studies Rijksuniversiteit Groningen Groningen The Netherlands; Institute Biology Leiden Leiden University Leiden The Netherlands

St Antonius Hospital Nieuwegein The Netherlands; Institute Biology Leiden Leiden University Leiden The Netherlands

Zoologisches Institut der Universität University of Göttingen Göttingen Germany

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