Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Plant parasitic nematodes are microscopic worms in soil that feed on plant roots, stunt their growth and make root systems much less efficient at withdrawing nutrients and water from soil. The yields of nematode-infected crop plants are reduced and annual losses world wide are estimated to cost US$100b, despite control measures. In the UK the major nematode pest, potato cyst nematodes, causes £50m of yield losses each year to the potato crop. Nematodes usually do not cause characteristic symptoms in plants and the general stunting of infected crops is often attributed to other causes; nematodes are frequently referred to as the hidden enemy. In intensive cropping systems growers depend on host resistance and chemicals (nematicides) to manage nematode pests. Nematicides are some of the most toxic products used in crop protection and their use has been banned in several European countries because of environmental concerns and public pressures to reduce dependence on agro-chemicals. There is an urgent need to develop other control methods to replace current nematicides. This research proposal builds on recent work at Rothamsted Research that has demonstrated that root-knot nematodes, which include the most important nematode pests in world agriculture, may use indole acetic acid and other plant-derived indole compounds to locate and invade host-plant roots in soil. We will confirm this observation and identify the most active compounds. We will also investigate how these compounds cause changes in nematode behaviour and guide them to infection sites. The output of this project will provide nematode targets for chemical or genetic intervention. Interfering with host recognition processes, offers great promise for the design of efficient, specific, safe and environmentally friendly management tactics to limit plant damage due to major groups of nematode pests, including the potato cyst nematodes.

With increasing recognition of the importance of insects, there are growing concerns that insect biodiversity has declined globally, with serious consequences for ecosystem function and services. Yet, gaps in knowledge limit progress in understanding the magnitude and direction of change. Information about insect trends is fragmented, and time-series data are restricted and unrepresentative, both taxonomically and spatially. Moreover, causal links between insect trends and anthropogenic pressures are not well-established. It is, therefore, difficult to evaluate stories about "insectageddon", to understand the ecosystem consequences, to devise mitigation strategies, or predict future trends. To address the shortfalls, we will bring together diverse sources of information, such as meta-analyses, correlative relationships and expert judgement. GLiTRS will collate these diverse lines of evidence on how insect biodiversity has changed in response to anthropogenic pressures, how responses vary according to functional traits, over space, and across biodiversity metrics (e.g. species abundance, occupancy, richness and biomass), and how insect trends drive further changes (e.g. mediated by interaction networks). We will integrate these lines of evidence into a Threat-Response model describing trends in insect biodiversity across the globe. The model will be represented in the form of a series of probabilistic statements (a Bayesian belief network) describing relationships between insect biodiversity and anthropogenic pressures. By challenging this "Threat-Response model" to predict trends for taxa and places where high-quality time series data exist, we will identify insect groups and regions for which indirect data sources are a) sufficient for predicting recent trends, b) inadequate, or c) too uncertain. Knowledge about the predictability of threat-response relationships will allow projections - with uncertainty estimates - of how insect biodiversity has changed globally, across all major taxa, functional groups and biomes. This global perspective on recent trends will provide the basis for an exploration of the consequences of insect decline for a range of ecosystem functions and services, as well as how biodiversity and ecosystem properties might be affected by plausible scenarios of future environmental change. GLiTRS is an ambitious and innovative research program: two features are particularly ground-breaking. First, the collation of multiple forms of evidence will permit a truly global perspective on insect declines that is unachievable using conventional approaches. Second, by validating "prior knowledge" (from evidence synthesis) with recent trends, we will assess the degree to which insect declines are predictable, and at what scales.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.