KESS II Funded PhD Studentship: Optimising the impact of semiochemicals for thrips monitoring and control

*This scholarships is part funded by the Welsh Government’s European Social Fund (ESF) convergence programme for West Wales and the Valleys.*

Swansea University is a UK top 30 institution for research excellence (Research Excellence Framework 2014), and has been named Welsh University of the Year 2017 by The Times and Sunday Times Good University Guide.

The Western flower thrips (WFT), Frankliniella occidentalis, is a major pest of crops worldwide causing estimated losses of US$ 1 billion per annum. WFT cause damage through feeding and by vectoring plant virus diseases. WFT reproduce rapidly resulting in pesticides having to be applied frequently to keep the population under control. Not surprisingly, WFTs rapidly develop resistance to chemical pesticides. Organic growers make routine introductions of predators (e.g. Amblyseius cucumeris, Amblyseius swirskii, Orius laevigatus) to control this pest but their use is inadequate when thrips populations are already high. The thrips’ small size and cryptic nature enables it to escape detection allowing a rapid build-up of populations. Early detectionwould allow timely intervention with more environmentally friendly control methods.

WFT are currently monitored using blue and yellow sticky traps to which they are strongly attracted. Several thrips attractants (pheromones, kairomones) have been identified which could be used with the sticky traps to provide a much improved “early warning” monitoring system. Such tools could also be used: (1) to locate routes of entry into protected crop systems and areas where the pest was flourishing, i.e. “hot spots”, allowing timely and appropriate control measures to be implemented, and (2) to excite thrips and increase their exposure to control agents whether they be biopesticides (e.g. soaps, entomopathogenic fungi), arthropod predators or conventional insecticides.

Understanding thrips’ responses to attractants in growing crops is critical if the use of these products is to be optimized. Already variability has been reported between different populations of thrips as regards their olfactory perception and olfactory behaviour to methyl isonicotinate. WFT from Spain appeared to be less responsive to this chemical than populations from other parts of the world. Other workers have reported that mixing odours of host and non-host plants may disrupt their olfactory orientation. For example, geraniol is attractive to WFT when applied to its host Chrysanthemum but not the non-host Sinningia. Other factors may also influence the level of response such as the release rate of the active which would be dependent upon temperature, airflow and dispenser type. There is also the possibility of thrips becoming habituated to the compound.

The current project focuses on optimising the use of selected attractants: (1) through the use of appropriately designed, inexpensive dispensers to optimise release rates and reduce product costs, (2) preparing blends that act synergistically, reducing application rates and costs, (3) deploying them in crops to enhance the efficacy of control agents (e.g. predators, soaps or insecticides), and (4) ensuring they are robust and function in different crop types and regions. Work will be carried out in the Departments of Biosciences (under Prof Tariq Butt) and Chemistry (under Dr Joel Loveridge) in Swansea University, in collaboration with Agrisense, a company which designs, develops and manufactures bio-rational trapping products for home and garden use throughout the world.

Scholarships are collaborative awards with external partners including SME’s and micro companies, as well as public and third sector organisations. The scholarship provides 3 years of funding with a 6 month period to complete the thesis. The achievement of a postgraduate skills development award, PSDA, is compulsory for each KESS II scholar and is based on a 60 credit award.

Eligibility:

Candidates should have a 2.1 or above in their undergraduate degree in biosciences or chemistry or a related subject. They should also be eligible for UK/EU Fees.