Insects, agriculture and environmental change

Insects, agriculture and environmental change

How do insect populations and communities respond to environmental change, and what are the functional consequences?

Insects have important effects on agricultural production and sustainability as pests, pollinators and nutrient cyclers. Populations of many insect species are declining, while others are increasing, leading to shifts in the structure and composition of farmland insect communities. This project will investigate how different drivers of environmental change (including pesticide use and climate change) affect insect populations and communities, and the ecosystem services and disservices that they mediate.

Aims of the Project

Focusing on functionally important insect taxa, the student will:

1. Explore the response of sets of interacting species to altered temperatures and pesticide exposure, acting alone and in combination

2. Compare community-level responses to environmental change to those predicted on the basis of functional traits and the physiology and demography of component species

3. Quantify the consequences of altered insect communities for agro-ecosystem functions, services and disservices

Project Description

Insects have major effects on agricultural production as pollinators and pests of crops, and through their effects on nutrient cycling and soil fertility. There is growing evidence that populations of some insect species are declining, while others increase, with potentially far-reaching consequences for agricultural production and sustainability. Changes in farmland management, pesticide use and climate change have all been implicated in affecting insect populations and communities, but the relative importance of these factors, how they interact, and the mechanisms through which they act remain poorly understood. Furthermore, the functional consequences of changing insect communities for agricultural production are poorly understood, despite their relevance to agricultural policy (for example, in informing the design of agri-environment schemes).

The DPhil student will explore the independent and interacting effects of habitat change, pesticide use and climate change on functionally-important insect taxa within UK agro-ecosystems. Within the overall theme, there is flexibility to focus on particular approaches and study systems depending on the interests of the student. Potential focal taxa are functionally-important dung beetles (nutrient cyclers in pastures), hoverflies (crop pollinators) and aphids (crop pests). The student will carry out small-scale experiments, manipulating temperatures and exposure to pesticides alone and in combination, and measuring the consequences for the performance of individuals, populations and communities. The resulting data will be used to assess the likely functional consequences of changes to the composition of insect communities, and to model the biodiversity and ecosystem-service consequences of alternative agricultural intensification and climate change scenarios.

Methods to be used

Field sampling of insects, laboratory assays of thermal tolerance and the effects of pesticides, mesocosm experiments using multiple interacting species

Specialised skills required

Practical experience of entomological field and/or laboratory work would be an advantage

This project will be carried out in collaboration with the John Oldacre Trust

If you are interested in this project please contact owen.lewis@zoo.ox.ac.uk