title: Fungal Associates of the Xylosandrus compactus (Coleoptera: Curculionidae, Scolytinae) Are Spatially Segregated on the Insect Body.
abstract: Studies of symbioses have traditionally focused on explaining one-to-one interactions between organisms. In reality, symbioses are often much more dynamic. They can involve many interacting members, and change depending on context. In studies of the ambrosia symbiosis-the mutualism between wood borer beetles and fungi-two variables have introduced uncertainty when explaining interactions: imprecise symbiont identification, and disregard for anatomical complexity of the insects. The black twig borer, Xylosandrus compactus Eichhoff, is a globally invasive ambrosia beetle that infests >200 plant species. Despite many studies on this beetle, reports of its primary symbionts are conflicting. We sampled adult X. compactus and infested plant material in central Florida to characterize the fungal symbiont community using dilution series, beetle partitioning, and DNA-based identification. X. compactus was consistently associated with two fungal taxa, Fusarium spp. and Ambrosiella xylebori Multivariate analyses revealed that A. xylebori was strongly associated with the beetle mycangium while Fusarium spp. were associated with the abdomen and external surfaces. The Fusarium spp. carried by X. compactus are not members of the Ambrosia Fusarium Clade, and are probably not mutualists. Fungal community composition of the mycangium was less variable than external body surfaces, thus providing a more consistent fungal inoculum. This is the first report of spatial partitioning as a mechanism for maintenance of a multimember ambrosia fungus community. Our results provide an explanation for discrepancies among previous reports, and suggest that conflicting results are not due to differences in symbiont communities, but due to inconsistent and incomplete sampling.
authors.affiliation: Department of Entomology and Nematology, Institute of Food and Agricultural Sciences, University of Florida, PO Box 110410, Gainesville, FL 32611-0410 (batemanc@gmail.com; hulcr@ufl.edu).
authors.forename: Craig
authors.initials: C
authors.lastname: Bateman
authors.affiliation: Department of Biology and Ecology, Faculty of Science, University of Ostrava, Dvořákova 7, 701 03 Ostrava, Czech Republic (marton.sigut@gmail.com).
authors.forename: Martin
authors.initials: M
authors.lastname: Šigut
authors.affiliation: School of Forest Resources and Conservation, Institute of Food and Agricultural Sciences, University of Florida, PO Box 110410, Gainesville, FL 32611-0410 (skelto3@gmail.com; smithk@ufl.edu).
authors.forename: James
authors.initials: J
authors.lastname: Skelton
authors.affiliation: School of Forest Resources and Conservation, Institute of Food and Agricultural Sciences, University of Florida, PO Box 110410, Gainesville, FL 32611-0410 (skelto3@gmail.com; smithk@ufl.edu), Southern Institute of Forest Genetics, USDA Forest Service, Southern Research Station, Saucier, MS 39574 and.
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Smith
authors.affiliation: Department of Entomology and Nematology, Institute of Food and Agricultural Sciences, University of Florida, PO Box 110410, Gainesville, FL 32611-0410 (batemanc@gmail.com; hulcr@ufl.edu), School of Forest Resources and Conservation, Institute of Food and Agricultural Sciences, University of Florida, PO Box 110410, Gainesville, FL 32611-0410 (skelto3@gmail.com; smithk@ufl.edu), hulcr@ufl.edu.
authors.forename: Jiri
authors.initials: J
authors.lastname: Hulcr
mesh_terms: D000818:Animals; D001203:Ascomycota / Q000235:genetics / Q000502:physiology; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005260:Female; D005431:Florida; D005658:Fungi / Q000235:genetics / Q000502:physiology*; D005670:Fusarium / Q000235:genetics / Q000502:physiology; D017422:Sequence Analysis, DNA; D013559:Symbiosis; D048889:Weevils / Q000382:microbiology*
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal
keywords: Ambrosiella; Fusarium solani; black twig borer; mutualism; mycangium