Locust Pests and Biological Control in Argentina during the First Half of the Twentieth Century

In the first decades of the twentieth century, the so-called “mechanical” and "chemical" means were the most frequent answer when locust swarms threatened the crops. Different governments and administrations around the globe resorted either to the use of traps, barriers, fire or to digging up eggs along with poisoned baits or insecticides to eradicate this "natural threat". The history of these means in the fight against locusts -and other agricultural pests- have received much attention from scholars, especially in the case of insecticides. This tendency, however, cast a shadow on the history of the “biological” methods. At the end of the nineteenth and beginnings of the twentieth century, this enterprise was taken up enthusiastically by entomologists and other scientists worldwide and numerous trial introductions were made in the following decades under various degrees of scientific control. This implied a global circulation not only of knowledge, technologies, peoples, and instruments but also of different kind of organisms. The new field presented the promise of a natural, pest-free future for agriculture although the results obtained were controversial, particularly for combating locusts. This perspective underlined that insect pests were a consequence of an ecological/environmental disorder and its solution entailed to restore "the balance of nature". Not just to eradicate or manage a particular "plague" but to control nature. Here I will focus on this subject through the study of different experiences on locust biological control and its narratives in Argentina during the first half of the twentieth century.