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Locusts are major intermittent threats to food security and the ecological factors determining where and when these occur remain poorly understood. For many herbivores, obtaining adequate protein from plants is a key challenge. We tested how the dietary protein : non-structural carbohydrate ratio (p : c) affects the developmental and physiological performance of 4th-5th instar nymphs of the South American locust, Schistocerca cancellata, which has recently resurged in Argentina, Bolivia and Paraguay. Field marching locusts preferred to feed on high carbohydrate foods. Field-collected juveniles transferred to the laboratory selected artificial diets or local plants with low p : c. On single artificial diets, survival rate increased as foods became more carbohydrate-biased. On single local plants, growth only occurred on the plant with the lowest p : c. Most local plants had p : c ratios substantially higher than optimal, demonstrating that field marching locusts must search for adequate carbohydrate or their survival and growth will be carbohydrate-limited. Total body lipids increased as dietary p : c decreased on both artificial and plant diets, and the low lipid contents of field-collected nymphs suggest that obtaining adequate carbohydrate may pose a strong limitation on migration for S. cancellata . Anthropogenic influences such as conversions of forests to pastures, may increase carbohydrate availability and promote outbreaks and migration of some locusts.

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.

The sugarcane weevil, Acrotomopus atropunctellus (Boheman) (Coleoptera: Curculionidae) is an increasingly important sugarcane pest in Argentina. Its emergence period overlaps with early stages of sugarcane phenology. This research assessed the preference of A. atropunctellus for shoot size and the effect of damage on shoot survival. Acrotomopus atropunctellus preferred to feed on large- and mediumsized shoots, regardless of sex. However, older plants were resistant to injury. Also, the number of punctures produced by females was 1.6 times greater than that produced by males. Avoiding late planting or harvest dates could be a useful tactic for mitigating A. atropunctellus incidence in sugarcane crops.

Different biological parameters of the stink bugs, Nezara viridula L. and Piezodorus guildinii Westwood (Hemiptera: Pentatomidae), are affected by the developmental stage of the soybean (Glycine max Merrill) pods they feed on. These effects of the soybean on the stink bugs could represent a selection pressure leading to the ability of these species to discriminate the phenological stage of soybean pods, and, therefore, to exhibit feeding preferences. We designed three studies: (1) Distant detection of soybean pods through an olfactometer; (2) Free choice tests to evaluate preferences for soybean pods of different developmental stages; (3) No choice tests to study effects of soybean pod development on feeding time and number of probes. Stink bugs showed no differential response to olfactometer arms with or without soybean pods, suggesting an inability to detect soybean volatiles. Free choice tests showed no species effects on pods selection, but significant differences among fifth instar nymphs, adult male, and adult females. Fifth instar nymphs fed more frequently on soybean pods of advanced development stages compared to female adults, despite previous evidence showing poor development of stink bugs fed pods of the same stage. No choice tests showed significant effects of stink bug species, stink bug stage and sex, and soybean pod phenology. N. viridula expressed shorter feeding times and higher numbers of probes than P. guildinii. The highest numbers of probes of both species were observed when they were fed soybean pods in early phenological stages. When placed in direct contact with food, fifth instar nymphs prefered to feed on more developed pods, despite these pods being suboptimal food items. These results suggest that for the ecological time framework of soybean-stink bugs coexistence, around thirty-five years in Argentina, the selection pressure was not enough for stink bugs to evolve food preferences that match their performance on soybean pods of different development stages.

Locusts and other migratory grasshoppers are transboundary pests. Monitoring and control, therefore, involve a complex system made up of social, ecological, and technological factors. Researchers and those involved in active management are calling for more integration between these siloed but often interrelated sectors. In this paper, we bring together 38 coauthors from six continents and 34 unique organizations, representing much of the social-ecological-technological system (SETS) related to grasshopper and locust management and research around the globe, to introduce current topics of interest and review recent advancements. Together, the paper explores the relationships, strengths, and weaknesses of the organizations responsible for the management of major locust-affected regions. The authors cover topics spanning humanities, social science, and the history of locust biological research and offer insights and approaches for the future of collaborative sustainable locust management. These perspectives will help support sustainable locust management, which still faces immense challenges such as fluctuations in funding, focus, isolated agendas, trust, communication, transparency, pesticide use, and environmental and human health standards. Arizona State University launched the Global Locust Initiative (GLI) in 2018 as a response to some of these challenges. The GLI welcomes individuals with interests in locusts and grasshoppers, transboundary pests, integrated pest management, landscape-level processes, food security, and/or cross-sectoral initiatives.

Locusts and other migratory grasshoppers are transboundary pests. Monitoring and control, therefore, involve a complex system made up of social, ecological, and technological factors. Researchers and those involved in active management are calling for more integration between these siloed but often interrelated sectors. In this paper, we bring together 38 coauthors from six continents and 34 unique organizations, representing much of the social -ecological -technological system (SETS) related to grasshopper and locust management and research around the globe, to introduce current topics of interest and review recent advancements. Together, the paper explores the relationships, strengths, and weaknesses of the organizations responsible for the management of major locust -affected regions. The authors cover topics spanning humanities, social science, and the history of locust biological research and offer insights and approaches for the future of collaborative sustainable locust management. These perspectives will help support sustainable locust management, which still faces immense challenges such as fluctuations in funding, focus, isolated agendas, trust, communication, transparency, pesticide use, and environmental and human health standards. Arizona State University launched the Global Locust Initiative (GLI) in 2018 as a response to some of these challenges. The GLI welcomes individuals with interests in locusts and grasshoppers, transboundary pests, integrated pest management, landscape -level processes, food security, and/or cross-sectoral initiatives.

Nowadays, travel surveys provide rich information about urban mobility and commuting patterns. But, at the same time, they have drawbacks: they are static pictures of a dynamic phenomena, are expensive to make, and take prolonged periods of time to finish. However, the availability of mobile usage data (Call Detail Records) makes the study of urban mobility possible at levels not known before. This has been done in the past with good results--mobile data makes possible to find and understand aggregated mobility patterns. In this paper, we propose to analyze mobile data at individual level by estimating daily journeys, and use those journeys to build Origin-Destiny matrices to understand urban flow. We evaluate this approach with large anonymized CDRs from Santiago, Chile, and find that our method has a high correlation (\\(\\rho = 0.89\\)) with the current travel survey, and that it captures external anomalies in daily travel patterns, making our method suitable for inclusion into urban computing applications.