Effects of global environmental changes on parasitoid-host food webs and biological control

•Food-web approaches quantify changes to community-wide interactions.•For biocontrol, webs quantify attack rates, non-target impacts, use of alternative hosts, etc.•An increasing number of studies are finding effects of environmental changes on parsitoid–host networks.•Changes to biomass at different trophic levels, web complexity and interaction evenness have all been shown.