An erroneous assumption

In 1992, in Campinas, Brazil, the magazine Globo Ciência comes to report on these scientists trying to understand the locust outbreaks damaging crops in the states of Mato Grosso and Rondonia for several years. In these two photos, I'm with a Brazilian colleague, entomologist, who accompanied me in all my fieldwork in Mato Grosso between 1992 and 1996 to study the biology and ecology of the responsible species, Rhammatocerus schistocercoides, a locust described by the entomologist J.A.G. Rehn in 1906, then passed into oblivion. So much so that following the first outbreaks in 1984, it was difficult to recognize the species and to name it.

I arrived in Campinas at the end of the summer of 1992 to work in the center of Satellite Monitoring of EMBRAPA (Brazilian Corporation of Agricultural Research). This center was responsible for the development of geo-information for territorial management and a sustainable agriculture. We hoped, with satellite Landsat images, map the habitats of this pest locust and analyze the relationships with the development of agriculture in these regions of the new agricultural frontiers in Brazil. Indeed, on the pioneer fronts on the southern edge of the Amazon, from the 70s, new areas were developed and planted with rice, sugarcane, soybean... Very quickly locust outbreaks came compromising crops. The assumption at the time was that the expansion of mechanized farming had changed the natural balance and was the cause of these outbreaks. According to this hypothesis, the intensive deforestation carried out in the cerrado to create croplands and pasturelands would have created new biotopes suitable for locusts, or an upset in the ecological balance would have considerably reduced natural locust predators and promoted the outbreaks. So, new farmers got just what they deserved!

With Brazilian colleagues, I was able to show that this was not the case, far from it. I studied the ecology of this locust species. I also explored relentlessly the areas concerned, especially in the Chapada dos Parecis. I interviewed many old people: missionaries Jesuits and Salesians, indian Parecis and Nambiquaras, gold miners, old farmers, 'seringueros' (rubber tappers), breeders... all the pioneers of the colonization of Mato Grosso who attended the region in the first half of the 20th century. I also looked for evidence in the old literature relating the exploration of Mato Grosso (E. Roquette-Pinto, Marshal Candido M. da Silva Rondon...). It was such a fascinating study! Surely one of the best moments in my career. I was able to build up a set of facts showing that outbreaks of this locust species, in the cerrado, at the southern border of the Amazon rainforest, had always existed. The evidences obtained from publications or orally clearly indicated that locust outbreaks in this region are a long-standing phenomenon, both in terms of their extent and nature. This locust species has always been so plentiful that they are daily eaten by the Indians Nambiquaras who are very fond of it, as reported by Claude Levi-Strauss in Tristes Tropiques. They are also part of the creation myths of the world for the indian Parecis.

Therefore, theories on the origins of these outbreaks were drastically revised. Especially those that blames the accelerated agricultural development that has occurred in these regions since the 70s. In fact, the new farmers had settled in the territory of locusts! I was quite proud of the result.

Lecoq M., Pierozzi Jr. I., 1995. Rhammatocerus schistocercoides locust outbreaks in Mato Grosso (Brazil): a long-standing phenomenon. The International Journal of Sustainable Development and World Ecology, 2: 45-53.

Lecoq M., Pierozzi Jr. I., 1995. Le criquet du Mato Grosso : l’agriculture est-elle responsable ? Tropicultura, 13 (1) : 32-33.