Importance of human capital, field knowledge and experience to improve pest locust management.

Background: A poorly organised risk management system may dysfunction when used. The consequences can be dramatic for those supposed to be protected. Since the 1960s, preventive control strategies, with field officers as living memory, have been developed to monitor locusts.

On the relative role of climate change and management in the current desert locust outbreak in East Africa.

While large-scale monitoring, early detection and control can greatly reduce desert locust invasions, global change is most likely to affect conditions that promote the transition from solitary to gregarious populations. Although climate change scenarios point to an increase in aridity and further desertification in vast areas of Africa, some regions that have been at the origin of past outbreaks are likely to see a reversed trend (i.e.

The limitations of locust preventive management faced with spatial uncertainty: exploration with a multi-agent model.

Background: The spatial structure of locust outbreaks is a major aspect of preventive management that relies on where survey teams have to be sent if they are to react in time to any upsurge. The concentration of areas propitious to outbreaks has been documented for many species. Areas where preventive management fails to collect information because of insecurity or remoteness constitute other limits.

Locust and Grasshopper Management.

Locusts and grasshoppers (Orthoptera: Acridoidea) are among the most dangerous agricultural pests. Their control is critical to food security worldwide and often requires governmental or international involvement. Although locust and grasshopper outbreaks are now better controlled and often shorter in duration and reduced in extent, large outbreaks, often promoted by climate change, continue to occur in many parts of the world.

Improving preventive locust management: insights from a multi-agent model.

Background: Preventive management of locust plagues works in some cases but still fails frequently. The role of funding institution awareness was suggested as a potential facilitating factor for cyclic locust plagues. We designed a multi-agent system to represent the events of locust plague development and a management system with three levels: funding institution, national control unit and field teams.

Climate-driven geographic distribution of the desert locust during recession periods: Subspecies' niche differentiation and relative risks under scenarios of climate change.

The desert locust is an agricultural pest that is able to switch from a harmless solitarious stage, during recession periods, to swarms of gregarious individuals that disperse long distances and affect areas from western Africa to India during outbreak periods. Large outbreaks have been recorded through centuries, and the Food and Agriculture Organization keeps a long-term, large-scale monitoring survey database in the area. However, there is also a much less known subspecies that occupies a limited area in Southern Africa.

Demographic processes shaping genetic variation of the solitarious phase of the desert locust.

Between plagues, the solitarious desert locust (Schistocerca gregaria) is generally thought to exist as small populations, which are particularly prone to extinction events in arid regions of Africa and Asia. Given the high genetic structuring observed in one geographical area (the Eritrean coast) by former authors, a metapopulation dynamics model involving repeated extinction and colonization events was favoured. In this study, we assessed the validity of a demographic scenario involving temporary populations of the solitarious phase of the desert locust by analysing large-scale population genetic data.

Phase polyphenism and preventative locust management.

The ecology of phase polyphenism plays a major role in locust swarm formation. We describe how recent advances in the understanding of phase polyphenism can be combined with existing management approaches as part of a preventative Desert locust management strategy. We start with a brief overview of phase polyphenism with particular emphasis on the role that resource distribution patterns play in the process of locust phase change.

Outbreaks, gene flow and effective population size in the migratory locust, Locusta migratoria: a regional-scale comparative survey.

The potential effect of population outbreaks on within and between genetic variation of populations in pest species has rarely been assessed. In this study, we compare patterns of genetic variation in different sets of historically frequently outbreaking and rarely outbreaking populations of an agricultural pest of major importance, the migratory locust, Locusta migratoria. We analyse genetic variation within and between 24 populations at 14 microsatellites in Western Europe, where only ancient and low-intensity outbreaks have been reported (non-outbreaking populations), and in Madagascar and Northern China, where frequent and intense outbreak events have been recorded over the last century (outbreaking populations).

Genetic variation for parental effects on the propensity to gregarise in Locusta migratoria.

Background: Environmental parental effects can have important ecological and evolutionary consequences, yet little is known about genetic variation among populations in the plastic responses of offspring phenotypes to parental environmental conditions. This type of variation may lead to rapid phenotypic divergence among populations and facilitate speciation. With respect to density-dependent phenotypic plasticity, locust species (Orthoptera: family Acrididae), exhibit spectacular developmental and behavioural shifts in response to population density, called phase change.