Chemical ecology of Cacosceles newmannii (Coleoptera: Cerambycidae: Prioninae) and its field application
Cacosceles newmannii is indigenous to Southern Africa. The species is thought to develop in white milkwood trees (Sideroxylon spp.), where it is not of economic concern, and has been collected from Eucalyptus plantations. An outbreak has recently (2016) been detected in sugarcane in Ntumeni (KZN) where it caused severe crop damage, resulting in significant economic loss.
This species’ host shift onto sugarcane poses an economic risk to the sugar industry. It is thus critical to understand the factors influencing this host plant change, be they biotic or abiotic; key behaviours (e.g. feeding and damage rates) and population abundance, and to assess the further risk of invasion into adjacent sugarcane growing areas.
Is multi-pronged. The first, is based on the chemical ecology of mating behaviour and potential lure development. Literature shows that adults of several species within the Prioninae respond to prionic acid, which is the sex pheromone of these species. Effluvia will be collected from adult females and physiological and behavioural responses to effluvia and synthetic prionic acid will be tested using electroantennographic (EAG) experiments and olfactometer bioassays. Effluvia from adult females will be analysed to determine the similarity of its pheromone to other species in the Prioninae. Similarly, known plant kairomones and entrainments of potential host plants will be similarly tested. Putative attractants will be explored for the possibility of making a species-specific lure for this pest species.
The second involves field detection of immature stages. Larvae and pupae are found in or below the stools of sugarcane. Their detection may be made easier by using aerial surveillance using drones/aerial or satellite imagery to identify/prioritize areas within infected fields which could then be field scouted. Depending on the false positive rate such technologies may facilitate monitoring for these life stages.
A third focal point will characterize the molecular diversity of populations in sugarcane fields, in comparison with those from forestry plantations and from historical collections. Phylogenetic analyses will determine the relationship of this species with other Cerambycidae, especially African species.
The ideal candidate should hold an MSc degree in Insect Chemical Ecology/Entomology or another relevant field, be enthusiastic about chemical ecology laboratory work, be especially diligent in the performance of bioassays, and able to apply the analyses to in-field situations. This is a team-orientated project and the ability to work effectively in a team environment is essential, as is a generous disposition.
This four year project (2018-2021) will be based at the Forestry and Agricultural Biotechnology Institute (FABI) at the University of Pretoria, with field sites in Entumeni, KZN. It includes collaboration from SASRI and Stellenbosch University. The successful candidate will be provided with a competitive bursary and a dynamic, well-resourced and friendly working environment. Though not an essential requirement, candidates seeking to secure NRF funding are encouraged to apply.
A résumé and cover letter indicating why the candidate feels he/she is the best person for the position should be sent by 30th November 2017, or as soon as possible after that to Prof Bernard Slippers, FABI, University of Pretoria ([email protected] ; www.fabinet.up.ac.za/bslippers ).