Mechanisms underlying phase change (swarm formation and break-up) in desert locusts

Applications from self-funded students are invited for a project that will focus on adaptive changes in neuronal function that are associated with locusts’ transitions to and from swarming behaviour (’phase change’ or ’density-dependent phase polyphenism’). The analyses will be multidisciplinary, providing in-depth training in quantitative behavioural measurements, electrophysiology, neurochemistry and genetics.

A central question in Biology is to determine how animals adapt to their changing environment - which they must do if they are to survive. The ability to do this, often referred to as ’plasticity’, is reflected at all levels of organisation from genetic, through cellular and organ function, to morphology and behaviour. Desert locusts (Schistocerca gregaria) show one of the most dramatic examples of such plasticity, which encompasses differences in behaviour, physiology, nervous system function, morphology and life history. This so-called ’phase change’ is driven by fluctuations in population density brought about by changes in the environment. At low population densities, locusts occur in the Solitarious Phase. These animals are cryptic in both appearance and behaviour. They walk slowly and infrequently, fly predominately at night, and avoid contact with other locusts. When population size increases or food is in short supply, solitarious locusts are forced together, and this causes them to transform into their Gregarious Phase. Gregarious locusts have bright warning colours as juveniles, walk a lot and with a rapid upright posture, fly during the day and, most importantly, are attracted to other locusts. This propensity means that they aggregate into vast swarms that can cause widespread devastation to crops. During phase change, behaviour is modified rapidly, within a few hours, whereas morphological changes take weeks or even several generations to arise. We rear both solitarious and gregarious locusts in the laboratory and can induce phase change experimentally, which makes them excellent models with which to analyse neuronal, behavioural and morphological plasticity.

The focus of the project will be tailored to the skills and interests of the successful candidate, but could address some of the following questions:
How does the neurohormone serotonin (which is a key element of the phase change pathway) regulate behaviour?
What is the molecular basis for differences in daily patterns of activity in solitarious and gregarious locusts?
How do differences in the visual systems of swarming and non-swarming locusts drive different behaviours?
How do phase-specific and species-specific differences in visual responses affect interactions of solitarious and gregarious locusts with predators in the field?

For an appropriate student, there may be opportunities to set up effective working links and training exchanges with field workers in affected countries.

Enthusiastic, hard-working students who wish to work in a multidisciplinary environment on an exciting project are encouraged to apply.

This post will remain open until filled. Informal enquiries are encouraged prior to formal application (contact Dr Tom Matheson, [Email Address Removed]). Some background to our work is provided on our web pages:

http://www2.le.ac.uk/departments/biology/people/matheson

Formal applications can be made online or by post: http://www2.le.ac.uk/study/research/phd/biology

We are an equal opportunities employer and particularly welcome applications for Ph.D. places from women, minority ethnic and other under-represented groups.