12 February 2016

Revealing the secrets of insect predator vs their aphid prey relationships in agricultural landscapes

Exclusion cagesThe Game & Wildlife Conservation Trust (GWCT) has contributed to a new report showing that simplification of agricultural landscapes can reduce natural pest control.

Over the past 20 years there have been many studies showing that changing the landscape of farmland to crop monocultures can reduce the abundance and diversity of aphids’ natural enemies. The effect on pest control however, remained poorly understood even though this is the key information needed by farmers. The latest study has changed this, however. By collecting data from 10 separate studies of aphids (greenfly) in which exclusion cages were used, the team led by Adrien Rusch at the French National Institute for Agricultural Research (INRA), analysed how the level of pest control was related to the increasing simplification of the surrounding land.

John Holland, Head of Farmland Ecology at the GWCT, explained how important the study is: “Our new study provides solid evidence that natural pest control is lower in landscapes dominated by agriculture. By understanding this, we can work with farmers to help them create new habitats to support more natural predators, such as beetles, spiders, hoverflies and parasitic wasps.”

Improving natural pest control has many environmental benefits, particularly whilst the pressure to reduce insecticide use is increasing. This pressure is coming from different sources, including European legislation to use pesticides more sustainably, concerns over effects to non-target speciesand increasing levels of resistance in pests.

The two-year study took place over Europe and North America, showing that the average level of pest control was 46% lower in homogeneous landscapes dominated by cultivated land, as compared with more complex landscapes. Preserving and restoring semi-natural habitats is a fundamental first step to maintain and enhance pest control services provided by predatory arthropods to agriculture.

For further information, please contact Dr John Holland on: email: jholland@gwct.org.uk or tel: 01425 01651035

Rusch A et al. 2016. Agricultural landscape simplification reduces natural pest control: A quantitative synthesis. Agriculture, Ecosystems and Environment. 221: 198–204.

Download the paper here free up until 26th March 2016.


Notes to editors

The Game & Wildlife Conservation Trust – providing research-led conservation for a thriving countryside. The GWCT is an independent wildlife conservation charity which has carried out scientific research into Britain’s game and wildlife since the 1930s. We advise farmers and landowners on improving wildlife habitats. We employ 22 post-doctoral scientists and 50 other research staff with expertise in areas such as birds, insects, mammals, farming, fish and statistics. We undertake our own research as well as projects funded by contract and grant-aid from Government and private bodies. The Trust is also responsible for a number of Government Biodiversity Action Plan species and is lead partner for grey partridge and joint lead partner for brown hare and black grouse.

For information, contact:
Eleanor Williams
Telephone: 07592 025476
Email: press@gwct.org.uk