PhD STUDY OPPORTUNITY
Modeling to aid release strategy and cost benefit decisions for Sterile Insect Technique 

The Problem
A necessary prerequisite for any Sterile Insect Technique (SIT) programme is a proper understanding of the physiological and behavioural aspects of the specific target insect in an SIT approach, as well as its cost benefit. The use of mathematical and simulation models for studying these interactions provides simulated answers, based on sound research findings, which can direct longer term research efforts. However, many of these have not been user-friendly, even though they have proved useful in progressing research on controlling Eldana saccharina  in an Area Wide Integrated Pest Management (AW-IPM) approach. This project will address this and will continue to reveal and provide direction to research opportunities, foremost of which is a cost-benefit analysis, linked to a combination of control options within an AW-IPM framework.

The Project (Due to commence January 2012)
Proposed further modelling work to build on past achievements include:
The current spatial model assumes diffusive migration of insects based on movement from high to low density areas. A possible refinement is to incorporate migration based on random insect movements, rather than deterministic diffusive movement. A possible heterogeneity in spatial movement based on the age of sugarcane fields is suspected, which can be incorporated into the current model by assuming variable diffusion coefficients, or to attach certain probabilities of movement to certain fields in the random migration model. Also, the current model does not distinguish between male and female migration, or between migration before or after mating. This might have an effect on the release ratios calculated by the current model.
The current model calculates the probabilities of matings based on proportion of sterile and fertile males and females. The effect of lek mating has not been investigated.
 Interaction with the host crop has been incorporated in the model, but only to a limited extent. The CANEGRO model needs to be incorporated more thoroughly. The current model correctly shows average infestation level increases over time, but seasonal larval peaks are not included.
The current model only considers the effect of SIT on E. saccharina infestation. SIT will be applied as part of an AW-IPM programme, which includes habitat management and biological control. The different control programmes need to be incorporated into one model to investigate their combined effect. This might impact largely on required release ratios, which may decrease SIT costs. It may also indicate better release timings, and best timing of other control measures.

The Candidate
The ideal candidate should hold an MSc degree in Mathematics, Mathematical Modelling, Statistics or Logistics, and be enthusiastic about ecological modelling. Entomological knowledge is advantageous. This is a team-orientated project and the ability to get on with others is essential.

The Position

The successful candidate will be based in the Department of Logistics, Stellenbosch University but provided with a competitive bursary and dynamic, well-resourced back-up from SASRI. Candidates who have secured or applied for NRF funding are strongly encouraged to apply.

The Contact
A resumé and covering letter, outlining why the candidate is suited to the position, should be sent  as soon as possible, but not later than 30 November 2011 to:
 Prof J. van Vuuren, Department of Logistics, Stellenbosch University. (vuuren@sun.ac.za)  OR
 Prof D.E. Conlong, SASRI, Private Bag X02, Mt Edgecombe, 4300. KZN. (des.conlong@sugar.org.za).