Predator-Prey Interactions between Shell-Boring Beetle Larvae and Rock-Dwelling Land Snails

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 intraspecifically 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

Data Predation Crete

This file provides information on the Cretan Albinaria collection samples used for producing the map of Drilus predation pressure. The samples without taxon identifiers were studied by Francisco W. Welter-Schultes and derived from the Haus der Natur, Cismar. The other samples were studied by Ruth F. Castillo Cajas and derived from the collection of Naturalis Biodiversity Center, Leiden

Data from: Predator-prey interactions between shell-boring beetle larvae and rock-dwelling land snails

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

Data Collection Codes

Collection details pertaining to the Albinaria samples, some containing Drilus laevae or adult, that were used in this stud

Appendix_PLOS ONE (herzien)- Voucher numbers - RMNH

This file contains all information relating to the Drilus specimens (adults, larvae, and exuviae) obtained from snail shells in the course of this study. Voucher numbers refer to the official collections in which the specimens were deposited

Greek <i>Albinaria</i> snails and their <i>Drilus</i> predators.

<p>A, <i>Albinaria hippolyti</i> from Crete (photo: V. Wiese). B and C, the clausilium, shown in the shell aperture after removal of the left lateral shell wall (B shows a less-obstructing, N-type clausilium, C shows a more obstructing, G-type clausilium). D and E, a male and a female, respectively, of a yet undescribed <i>Drilus</i> species from Crete (scale: 2 mm). F, a full-grown larva of <i>Drilus</i> “L” from the Peloponnese (same scale as D and E). G, an estivating <i>A. discolor</i> from the Peloponnese, with a <i>Drilus</i> exit bore hole. H, a <i>Drilus</i> “L” exiting from its prey, an <i>A. menelaus</i> from the Peloponnese.</p

A, five <i>Drilus</i> species from the Peloponnese have different specificities for <i>Albinaria</i> as prey, and concomitant propensities to bore holes in the shell (calculated as the number of bore holes divided by the total number of prey).

<p>B, difference (<i>P</i><0.05, Fisher's exact test) in prey specificity between <i>Drilus</i> “D” (more <i>Albinaria</i>-specific) and “E” (less <i>Albinaria</i> specific) in two localities where both species occur syntopically (these data are not included in fig. 3A). C, differences in <i>Drilus</i> predation rate (dark portion of the bar) between solitarily (“sol”) and group-wise (“agg”) estivating snails of <i>A. caerulea</i> in four 5 m² plots in the islands of Paros, Naxos, and Thira (voucher numbers RMNH.MOL.84354-84363, RMNH.MOL.85192, and RMNH.MOL.85193). An aggregate was defined as a cluster of >20 snails, with distances of <2 cm separating them. A snail was considered solitary if it was >20 cm distance from a conspecific (significance tested with Chi-square test). D, positions of entrance holes in shells of species with an N-type clausilium compared with those in shells of species with a G-type clausilium, shown for the entire eastern Peloponnese as well as for the site Monemvasia, where both clausilium types occur microsympatrically. (<i>P</i>-values are derived from Fisher's exact test.)</p

Map of Crete and surrounding islands, showing contours of regionally varying <i>Drilus</i> predation rates (given as percentages attacked shells per sample) in <i>Albinaria</i>, derived from bore-hole frequencies in 1,160 museum samples from Naturalis Biodiversity Center, Leiden, The Netherlands, Haus der Natur, Cismar, Germany, and Natural History Museum, Budapest, Hungary.

<p>Maps were drawn using inverse kriging distance calculation in R v.2.15.2 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0100366#pone.0100366-R1" target="_blank">[23]</a>, with packages gstat <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0100366#pone.0100366-Pebesma1" target="_blank">[24]</a>, maptools (R v.0.8-27), rgdal (R v.0.8-12) and rgeos (R v.0.3-2).</p

Still from Video S1, showing a <i>Drilus</i> “L” larva (in the lab) creating an exit bore-hole from within a prey <i>Albinaria meleaus</i>, followed by the lengthy procedure by which the larva emerges from the shell.

<p>Still from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0100366#pone.0100366.s008" target="_blank">Video S1</a>, showing a <i>Drilus</i> “L” larva (in the lab) creating an exit bore-hole from within a prey <i>Albinaria meleaus</i>, followed by the lengthy procedure by which the larva emerges from the shell.</p

Greek <i>Albinaria</i> snails and their <i>Drilus</i> predators.

<p>A, <i>Albinaria hippolyti</i> from Crete (photo: V. Wiese). B and C, the clausilium, shown in the shell aperture after removal of the left lateral shell wall (B shows a less-obstructing, N-type clausilium, C shows a more obstructing, G-type clausilium). D and E, a male and a female, respectively, of a yet undescribed <i>Drilus</i> species from Crete (scale: 2 mm). F, a full-grown larva of <i>Drilus</i> “L” from the Peloponnese (same scale as D and E). G, an estivating <i>A. discolor</i> from the Peloponnese, with a <i>Drilus</i> exit bore hole. H, a <i>Drilus</i> “L” exiting from its prey, an <i>A. menelaus</i> from the Peloponnese.</p