Insect populations are declining rapidly worldwide. The welfare implications extend from individual insects to the ecosystems that all animals — including humans — depend upon.
Insect biodiversity decline presents a welfare challenge at multiple scales. At the individual level, insects experiencing habitat loss, pesticide exposure, and light pollution face stressful and potentially harmful environments — though the extent to which this constitutes welfare harm in a morally relevant sense depends on contested evidence about insect sentience. At the ecosystem level, insect decline unambiguously impairs the welfare of all the vertebrate species that depend on insect-rich habitats for food and ecological function. The cascade from insect decline to bird, bat, amphibian, and fish population collapse creates enormous aggregate welfare harm for species whose sentience is not in doubt. Insect conservation is therefore a welfare priority regardless of the stance taken on insect sentience itself.