This is the final version. Available from Brill Academic Publishers via the DOI in this record. During the eighteenth century, the discovery of sexual reproduction in insect species prompted the demise of spontaneous generation and new developments in natural history, theology, and political economy. The sexual lives of insects prompted debates on whether insects were governed by desire, free will, and even marital tendency. Fuelled by the democratisation of microscopy, early modern entomology took a new turn and breadth: the study of insects and of their sexual lives provided unexpected new insights into human sexuality, reproduction, and Malthusian fears of overpopulation. This article surveys the intellectual culture of entomology and na...