It is the most harmful locust of South America. It was the most serious agricultural pest of Argentina during the first half of the XX century. Almost no crops escaped damages caused by the locust swarms. Fifteen thousand tons of locusts were stored in Entre Rios province only during 1934-5. By 1936, 60.000 km of metal barriers were available for guiding nymphs to collecting pits where they were burned by some of the 200.000 burners of the Acridological Service. Seven thousand men were involved in control activities during 1947-8, and 12.000 tons of insecticides were used. Since 1954, the invasion of agricultural lands has been avoided by a preventive approach of nymph control, restricting the pest mostly to the outbreak area in Catamarca and La Rioja (Gaston, 1969; COPR 1982).However, that the locust persist as a threat was observed in 1988, when preventive measures were relaxed and a much larger control operation against swarms was needed (Hunter & Cosenzo, 1990), and again in 2015-2016 when swarms and bands of nymphs occurred in Santiago del Estero.
The ilustrated distribution corresponds, with the exception of Chile (where the locust remains in solitary phase), to the maximun historical invasion area (Waloff & Padgley, 1986).The recession area (wich coincides with the “acridiogenous area” of Barrera and Turk, 1983), although smaller, still covers a large area (900.000 km2) that reaches from southeast Bolivia and western Paraguay to northwest Mendoza. The outbreak area is much smaller, extending from central-southeastern Catamarca and La Rioja, eastern San Juan, northwestern San Luis and Cordoba, and southwestern Santiago del Estero.
Polyphagous, many wild and cultivated plants