title: Cryptic diversity, high host specificity and reproductive synchronization in army ant-associated Vatesus beetles.
abstract: Army ants and their arthropod symbionts represent one of the most species-rich animal associations on Earth, and constitute a fascinating example of diverse host-symbiont interaction networks. However, despite decades of research, our knowledge of army ant symbionts remains fragmentary due to taxonomic ambiguity and the inability to study army ants in the laboratory. Here, we present an integrative approach that allows us to reliably determine species boundaries, assess biodiversity, match different developmental stages and sexes, and to study the life cycles of army ant symbionts. This approach is based on a combination of community sampling, DNA barcoding, morphology and physiology. As a test case, we applied this approach to the staphylinid beetle genus Vatesus and its different Eciton army ant host species at La Selva Biological Station, Costa Rica. DNA barcoding led to the discovery of cryptic biodiversity and, in combination with extensive community sampling, revealed strict host partitioning with no overlap in host range. Using DNA barcoding, we were also able to match the larval stages of all focal Vatesus species. In combination with studies of female reproductive physiology, this allowed us to reconstruct almost the complete life cycles of the different beetle species. We show that Vatesus beetles are highly adapted to the symbiosis with army ants, in that their reproduction and larval development are synchronized with the stereotypical reproductive and behavioural cycles of their host colonies. Our approach can now be used to study army ant-symbiont communities more broadly, and to obtain novel insights into co-evolutionary and ecological dynamics in species-rich host-symbiont systems.
authors.affiliation: Laboratory of Social Evolution and Behavior, The Rockefeller University, New York, NY, 10065, USA.
authors.forename: Christoph
authors.initials: C
authors.lastname: von Beeren
authors.affiliation: The Kyushu University Museum, Fukuoka, 812-8581, Japan.
authors.forename: Munetoshi
authors.initials: M
authors.lastname: Maruyama
authors.affiliation: Laboratory of Social Evolution and Behavior, The Rockefeller University, New York, NY, 10065, USA.
authors.forename: Daniel J C
authors.initials: DJ
authors.lastname: Kronauer
mesh_terms: D000818:Animals; D001000:Ants; D044822:Biodiversity; D002467:Cell Nucleus / Q000235:genetics; D001517:Coleoptera / Q000145:classification / Q000235:genetics / Q000502:physiology*; D003364:Costa Rica; D058893:DNA Barcoding, Taxonomic; D004272:DNA, Mitochondrial / Q000235:genetics; D005260:Female; D007814:Larva; D008297:Male; D012098:Reproduction; D055703:Reproductive Physiological Phenomena; D013559:Symbiosis
chemical_list: D004272:DNA, Mitochondrial
keywords: DNA barcoding; cryptic species; host specificity; myrmecophiles; social parasitism; symbiosis