ALT “Ambivalent Insects” as Tools and Targets Lisa Onaga and Luísa Reis-Castro Abstract The binary categories of harm and benefit have often shaped how historians frame discussions of insects. Scientists also leverage the binary framing of insects as tools and targets to carry out their work, especially in the development of biological technologies for pest control. This essay emphasizes how binaries function in scientific practice. Two case studies spanning from the twentieth century to the recent past illustrate the shift away from chemicals in pest management and, in doing so, show the instability of binary categories over the longue durée. Noticing “ambivalent insects” affords a way to widen narrative options and identify new opportunities for investigating insect histories.