title: Acorn consumption improves the immune response of the dung beetle Thorectes lusitanicus.
abstract: Thorectes lusitanicus, a typically coprophagous species is also actively attracted to oak acorns, consuming, burying them, and conferring ecophysiological and reproductive advantages to both the beetle and the tree. In this study, we explored the possible relation between diet shift and the health status of T. lusitanicus using a generalist entomopathogenic fungus (Metarhizium anisopliae) as a natural pathogen. To measure the health condition and immune response of beetles, we analysed the protein content in the haemolymph, prophenoloxidase (proPO) content, phenoloxidase (PO) activity and mortality of beetles with diets based on either acorns or cow dung. Protein content, proPO levels and PO levels in the haemolymph of T. lusitanicus were found to be dependent on the type of diet. Furthermore, the beetles fed with acorns developed a more effective proPO-PO system than the beetles fed with cow dung. Furthermore, a significant decrease in mortality was observed when infected individuals were submitted to an acorn-based diet. In addition to enhancing an understanding of the relevance of dietary change to the evolutionary biology of dung beetles, these results provide a more general understanding of the ecophysiological implications of differential dietary selection in the context of fitness.
authors.affiliation: IUI Centro Iberoamericano de la Biodiversidad, Universidad de Alicante, San Vicente del Raspeig, Alicante, Spain. jr.verdu@ua.es
authors.forename: José R
authors.initials: JR
authors.lastname: Verdú
authors.forename: José L
authors.initials: JL
authors.lastname: Casas
authors.forename: Vieyle
authors.initials: V
authors.lastname: Cortez
authors.forename: Belén
authors.initials: B
authors.lastname: Gallego
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Lobo
mesh_terms: D000818:Animals; D004156:Catechol Oxidase / Q000378:metabolism; D002417:Cattle; D001517:Coleoptera / Q000378:metabolism* / Q000502:physiology; D004032:Diet; D004792:Enzyme Precursors / Q000378:metabolism; D005243:Feces; D006458:Hemolymph / Q000378:metabolism; D014442:Monophenol Monooxygenase / Q000378:metabolism; D029963:Quercus
chemical_list: D004792:Enzyme Precursors; C038451:pro-phenoloxidase; D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase