There is now good evidence that insect populations are declining worldwide in both agricultural and protected natural landscapes, at about a rate of 1-2% per year. This doesn’t sound much, but maintained over decades it has already led to a serious loss of both insect biodiversity and biomass. It’s likely that there are multiple causes, including intensive agriculture, especially pesticides, as well as artificial light at night. Insects form the base of many ecological food chains and insect declines are likely to lead to a general loss of biodiversity.

Professor Stuart Reynolds (University of Bath) discusses evidence that insectivorous birds are already in trouble, and examines what can be done about the problem.