John Holland is Head of Farmland Ecology at the Game and Wildlife Conservation Trust. John studied Horticulture at Reading in the early 1980s, then after working on a farm for a year, studied for a MSc in Integrated Pest Management at Southampton University. This involved evaluating the effectiveness of a novel insecticide for locust control in Mali. He next went to New Zealand where for his PhD he investigated why spider mite resurgence occurred following pyrethroid insecticides. He joined the Game Conservancy Trust in 1992 to work on an Integrated Farming Systems project and when that completed in 1998 became Head of Entomology. Since then he has worked on a number of other large collaborative projects that have involved investigating the ecology of insects on farmland with the aim of understanding the impacts of farming practices or to develop techniques to enhance their numbers. Much of this work has focussed on beneficial insects and those important in the diet of farmland birds. Many studies were conducted on the spatial distribution of insects on farmland in relation to within field and surrounding attributes (weed cover, soils and non-crop habitats) in order to identify the controlling factors and so aid the development of management techniques. The scale of these studies extended over time from single fields to landscapes. Alongside these a range of studies were conducted to evaluate the efficacy of different types of natural enemy. He was coordinator for the QUESSA FP7 project (2013-17) that aimed to quantify the impact of semi-natural habitats on key ecosystem services such as pest control and pollination.
He was convenor of the International Organisation of Biological Control working group “Landscape Management for Functional Biodiversity” from 2009-2017 is convenor of the Royal Entomological Society “Sustainable Agriculture Group”. He has authored or co-authored more than 120 scientific publications, including 80 in peer reviewed journals.