Locust swarms affecting millions of people across Africa and Asia are controlled with insecticides causing mass mortality, raising welfare questions at the intersection of human food security and insect sentience.
The locust welfare question presents a genuine moral complexity: the food security of millions of people directly depends on controlling swarms that, if left unmanaged, cause famine. Whatever the probability of individual locust sentience, the arithmetic of tens of billions of individuals dying from insecticide application is significant. Biological controls using Metarhizium fungus cause slower death with unknown welfare implications but greater species selectivity. The precautionary principle suggests that within food security constraints, the least harmful effective control should be used.