In the first half of the twentieth century, the South American Locust (SAL), Schistocerca cancellata (Serville, 1838), was a major pest of agriculture in Argentina, Bolivia, Paraguay, Uruguay, and Brazil. From 1954–2014, a preventive management program appeared to limit SAL populations, with only small- to moderate-scale treatments required, limited to outbreak areas in northwest Argentina. However, the lack of major locust outbreaks led to a gradual reduction in resources, and in 2015, the sudden appearance of swarms marked the beginning of a substantial upsurge, with many swarms reported initially in Argentina in 2015, followed by expansion into neighboring countries over the next few years. The upsurge required a rapid allocation of resources for management of SAL and a detailed examination of the improvements needed for the successful management of this species. This paper provides a review of SAL biology, management history, and perspectives on navigating a plague period after a 60-year recession.

Bt crops exert high selective pressure on target pests. To mitigate resistance evolution the High-Dose/Refuge strategy (HDRS) requires: a) toxin expression in plant sufficiently high to render resistance alleles recessive; b) low initial frequency of the resistance allele; c) spatial refuges of non Bt crops. Gene pyramiding, the combination of two or more toxins in a transgenic plant, is proposed to reinforce the HDRS under the assumption of toxins having different binding sites to reduce the likelihood of cross-resistance. A recent review supports the strengths of the HDRS in delaying evolution of resistance. Failure to comply one or more of the requirements of the HDRS explains the few cases of confirmed field-evolved resistance. In San Luis, Argentina, significant damage by Diatraea saccharalis was detected in some Bt maize hybrids. Hypotheses to explain these high levels of crop damage, include low level of refuge compliance, dominance of a resistance allele, and low toxin expression. The low level of refuge adoption triggers discussions about the opportunity of promoting seed mixture refuges. A case by case approach is advocated to tailor IRM strategies according to the specific knowledge about the ecology of each pest.