Biodiversity of Parasitoid Networks and the Impact on Aphid Biocontrol
Prof N Birch
Dr G Begg
Dr R Hopkins
No more applications being accepted
Competition Funded PhD Project (European/UK Students Only)
Overview/Background The biodiversity of naturally occurring organisms can promote important ecological functions leading to greater sustainability in crop production systems. Conservation biocontrol (CBC), a strategy of Integrated Pest Management (IPM), seeks to contribute to the regulation of crop pests by conserving the abundance and diversity of their naturally occurring predator and parasitoid enemies. The introduction of semi-natural vegetation or other beneficial habitats is an effective way to conserve natural enemies. However, the knock-on effect of this on pest regulation is, at best, unreliable. The reasons for this are unclear. At its simplest it may not be because it is difficult to target the most effective natural enemies but more complex, indirect reasons. These are likely to arise given biodiversity’s tendency to increase trophic complexity, leading to phenomena like prey-switching, intra-guild predation, and hyper-parasitism, all of which may interfere with the ability of natural enemies to attack pest populations. Synchronisation between pests and their natural enemies is also a key factor in successful CBC strategies. Therefore, it is important that the apparent limitations of this approach are addressed so that effective strategies may be developed.
Aim/Scope This project will focus on aphid parasitoids and their hyper-parasitoids Using morphological and molecular taxonomic and population genetic approaches, the project will identify and quantify the aphid-parasitoid-hyperparasitoid assemblages and food-webs found in semi-natural habitats, and on raspberry and potato crops, using one key aphid pest (see below) as the ‘link species’ between these ecosystems. Using this approach, field experiments will be conducted to assess the influence of semi-natural habitats on the aphids and parasitoids of adjacent perennial and annual crops, including changes in the food webs that may either promote or limit aphid biocontrol. In addition, the link between aphid and parasitoid assemblages on raspberry and potato crops will be considered as protected raspberry crops now provide (due to recent crop management changes in raspberry) a potential but previously unstudied source of the potato aphid, Macrosiphum euphorbiae, and any parasitoids they may harbor. The aphid based food webs on raspberry and potato are likely to differ; understanding these differences over multiple seasons will be key to developing future strategies for both crops and reduce pesticide use, thus further enhancing on-farm biodiversity.
The studentship is funded under the James Hutton Institute/University Joint PhD programme, in this case with the University of Greenwich. Applicants should have a first-class honours degree in a relevant subject or a 2.1 honours degree plus Masters (or equivalent).Shortlisted candidates will be interviewed in Jan/Feb 2018. A more detailed plan of the studentship is available to candidates upon application. Funding is available for European applications, but Worldwide applicants who possess suitable self-funding are also invited to apply