Band movement and thermoregulation in Schistocerca cancellata

International audienceHighlights:• Temperature and vegetation effects are keys to control marching locust bands.• A band of south American locust in Argentina displayed thermoregulation behaviours.• Gut contents at different times of the day showed continuous feeding activity.• Walking speed and travelled distances of the band decreased with vegetation density.• Marching and thermoregulation are similar for south American and desert locust.Abstract:At high density, juvenile locusts create marching hopper bands. Understanding the roles of temperature and vegetation on the movement of these bands shall allow to better forecast and control them. Following a hopper band in North Argentina in November 2019, we explored the thermoregulation behaviours of the South American locust, Schistocerca cancellata. Gut-content samples informed about the feeding status at different time of the day. Hoppers' body temperature was above cold air temperature in the mornings during basking and group-basking activities and before the onset of marching behaviour. Marching by walking or hopping was dominant at body temperatures close to 40°C. Jumping, stilting, shading and perching on plants were seen as thermoregulatory behaviours to avoid ground temperatures above 50°C. Feeding was observed throughout the day with continuous high gut contents despite an intermittent pattern of feeding-resting-marching. Speed and daily travelled distance of the front of the hopper band was depending on the type of encountered vegetation. Daily behavioural patterns, thermoregulatory behaviours, walking speed and daily travelled distances of S. cancellata were similar to the ones observed for the Desert locust, S. gregaria, in Africa. High air temperatures recorded during the observation times could explain the continuous feeding patterns. These species may have evolved behaviours of alternating consuming a bit and marching as a migration strategy to avoid staying where no food is available after the havoc left behind large hopper bands. Recommendations made for the control of Desert locust hopper bands can be extended to South American locust ones

A Review of the Biology, Ecology, and Management of the South American Locust, Schistocerca cancellata (Serville, 1838), and Future Prospects

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.EEA ManfrediFil: Trumper, Eduardo V. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi; ArgentinaFil: Cease, A.J. Arizona State University. School of Sustainability; Estados UnidosFil: Cigliano, M.M. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Universidad Nacional de La Plata. Centro de Estudios Parasitológicos y de Vectores; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Copa Bazán, F.C. Universidad Autónoma Gabriel René Moreno. Instituto de Investigaciones Agrícolas El Vallecito; BoliviaFil: Lange, C.E. Universidad Nacional de La Plata. Centro de Estudios Parasitológicos y de Vectores; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Medina, H.E. Servicio Nacional de Sanidad y Calidad Agroalimentaria (SENASA); ArgentinaFil: Overson, R.P. Arizona State University. School of Sustainability; Estados UnidosFil: Therville, C. Arizona State University. School of Sustainability; Estados UnidosFil: Pocco, M.E. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Entomología; Argentina. Universidad Nacional de La Plata. Centro de Estudios Parasitológicos y de Vectores; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Piou, C. Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD). Unité Mixte de Recherche Centre de Biologie pour la Gestion des Populations; FranciaFil: Zagaglia, G. Servicio Nacional de Sanidad y Calidad Agroalimentaria (SENASA). Sede Salta; ArgentinaFil: Hunter, D. Locust and Grasshopper Control; Australi