Ectosymbionts of aari: a promising solution for mass rearing phytoseiidae?

Symbiotic interactions between microorganisms and arthropods are known to be beneficial for many arthropod hosts. While endosymbionts are known to enhance host nutrition or to induce varies reproductive phenotypes, ectosymbionts, bacteria or fungi living in/upon the tegument of the host, are known for their effectiveness in providing protection or immunity, i.e. protecting the host against pathogenic microbials. Despite their importance in host survival, ectosymbionts have been overlooked. Over the past decades, most observations of arthropods required the use of destructive techniques in such a way that microorganisms living on the tegument were accidentally eliminated. With the advent of new microscopical and molecular techniques it is now possible to study ectosymbionts in situ. Recently, new interactions have been documented, most involving insects. Most if not all free-living mites transport bacteria and fungi on their tegument; the identity of these associations is still awaiting research. The Phytoseiidae are the most important mites in agriculture because of their capability and reliability as predators of pests of vegetables and crops. Several species are mass-reared and extensively applied as biological control agents. Their worldwide commercial use is under constant threat by emerging diseases, impoverishing mass rearing and weakening their predatory effectiveness. Any attempt to increase our knowledge on the biology of interactions between Phytoseiidae mites with their natural microflora will help to improve and strengthen their massive industrial production and enhance their rapid adaptation to new environments. This proposal aims to study the ectosymbiont-phytoseiidae interactions, using microscopy and molecular genetics combined with an ecological approach. Objectives and Timeline: 1-Test to prove beneficial effect of ectosymbionts (Year 1) 2-Ectosymbionts biodiversity and their host location. Molecular IDs of ectosymbionts from wildtypes and Certis Phytoseiidae (Years 1-2) 3-Replacement: Compare competitive replacement with forced replacement of ectosymbionts (Year 2) 4-Replacement and Mass Rearing. Compare Phytoseiidae with Certis and with wildtype ectosymbionts (Year 3) 5-Replacement and Competitiveness for fitness after release. Compare Phytoseiidae with Certis and with wildtype ectosymbionts (Years 3-4) This proposal is the genuine product of the interaction between academy and industry. The industrial partner is BCP Certis, a leading company for crop protection and pest control, and has initially approached the academic partner at Reading. The demand for food is escalating resulting in a wide expansion of crop production. Crop pests are thriving and there is an increasing demand for new controls. When possible the use of pesticides is being replaced by biological control. BCP Certis provides the beneficial agents to satisfy crop producers in Europe. BCP Certis seeks to find new remedies for mite disease to increase their massive production and enhance predatory fitness according to an ever increasing demand of their products. The supervisor at the University of Reading, M. Alejandra Perotti is one of a handful of acarologists in the UK with unique expertise in biology of predatory mites and symbiosis. The student will work with wildtype Phytoseiidae from the UK, South America and Spain. Microscopy and molecular analyses of ectosymbionts will be performed at Reading using state-of-the-art facilities at the BioCenter (for molecular work) and Center of Advance Microscopy (Electron microscopes). Objectives 1-2-3 will be carried out at the Acarology Lab in the School of Biological Sciences (SBS). BCP Certis has ample experience in massive rearing of commercial species currently producing 3 major predators; the student will perform objectives 4-5 at their experimental green houses.