Risk of migration: not all gregarious locust nymphs reach appropriate refuges.

Sedentary animals choose appropriate refuges against predators, while migratory ones may not necessarily do so. In ectotherms, refuge selection is critical during low temperatures, because they cannot actively evade predators. To understand how migratory ectotherms alter their defensive behaviors depending on refuge quality in cold temperatures, we evaluated migratory gregarious desert locust nymphs (Schistocerca gregaria) in the Sahara Desert, where daily thermal constraints occur.

Thermoregulatory behavior of lekking male desert locusts, Schistocerca gregaria, in the Sahara Desert.

Most terrestrial animals are constrained by extreme heat conditions such as midday desert environments, while a few terrestrial ectothermic insects are active in such ecological niches. Sexually mature males of the desert locust (Schistocerca gregaria) in the Sahara Desert remain on the open ground, despite the ground temperatures exceeding their lethal limit, to form leks and to mate incoming gravid females during the daytime. Lekking male locusts apparently suffer from extreme heat stress and greatly fluctuating thermal conditions.

Egg size-dependent embryonic development in the desert locust, Schistocerca gregaria.

Phenotypic plasticity in body size is a product of modification of the developmental pathway. Although hatchlings of the desert locust, Schistocerca gregaria, show egg size-dependent plasticity in body size, it remains unclear how embryogenesis during egg development regulates final embryonic body size. To determine the developmental pathway causing body size variation at hatching, we examined egg and embryonic development at the early, middle, and late egg developmental stages in S.

Allocation of more reproductive resource to egg size rather than clutch size of gregarious desert locust (Schistocerca gregaria) through increasing oogenesis period and oosorption rate.

The desert locust, Schistocerca gregaria, shows a density-dependent reproductive trade-off by laying fewer but larger eggs in crowded conditions (gregarious phase) than in isolated conditions (solitarious phase). However, the physiological mechanisms controlling reproductive resource allocation remain unclear. We examined how egg production processes, including ovulation timing (i.

Band movement and thermoregulation in Schistocerca cancellata.

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.

Density-dependent mating behaviors reduce male mating harassment in locusts.

Male mating harassment may occur when females and males do not have the same mating objectives. Communal animals need to manage the costs of male mating harassment. Here, we demonstrate how desert locusts in dense populations reduce such conflicts through behaviors.

A general model of the thermal constraints on the world's most destructive locust, Schistocerca gregaria.

All terrestrial ectotherms are constrained to some degree by their thermal environment and the extent to which they can behaviorally buffer variable thermal conditions. New biophysical modeling methods (NicheMapR) allow the calculation of the body temperature of thermoregulating animals anywhere in the world from first principles, but require detailed observational data for parameterization and testing. Here we describe the thermoregulatory biology of marching bands of the desert locust, Schistocerca gregaria, in the Sahara Desert of Mauritania where extreme heat and strong diurnal fluctuations are a major constraint on activity and physiological processes.

The desert locust, Schistocerca gregaria, plastically manipulates egg size by regulating both egg numbers and production rate according to population density.

Egg-size adjustment is one of the important plastic life-history traits for animals living in heterogeneous environments. The adaptive investment hypothesis predicts that mothers should increase progeny size according to certain cues predicting adverse future conditions of their offspring. However, reproductive resources are limited, and females have to simultaneously reduce egg number to allocate more resources to increase size.

Aggregation Site Choice by Gregarious Nymphs of the Desert Locust, , in the Sahara Desert of Mauritania.

Animals often aggregate at certain sites during vulnerable periods such as night-roosting as an anti-predatory strategy. Some migratory gregarious animals must regularly find new night-roosting sites, but how they synchronously choose such sites is poorly understood. We examined how gregarious nymphs of the desert locust, Forskål (Orthoptera: Acrididae), aggregate at certain plants for night-roosting in the Sahara Desert.

Daily microhabitat shifting of solitarious-phase Desert locust adults: implications for meaningful population monitoring.

The Desert locust Schistocerca gregaria is a major world pest that causes substantial agricultural and economic damage. Effective pest control relies on effective monitoring, which requires knowledge of locust microhabitat selection. Yet little is known about microhabitat selection of solitarious adult locusts in the field.