Biological control of mosquitoes globally has been highly variable in outcomes and desperately needs a fresh approach. Here, utilising native invertebrate predators of mosquitoes, this project will measure and harness variation in predatory efficiencies among individuals within populations, thus enhancing biocontrol whilst avoiding the use of ecologically damaging alien control agents. Behavioural, ecological and genetic techniques will form our blended approach to biocontrol research. We will operationalize the outcomes with roll-out of biocontrol training and education.
Biodiversity holds the keys to the management of pests and disease vectors across environments, yet much potential is unrealised. The development of biocontrol using predators of mosquitoes to tackle nuisance biting and disease transmission in humans and animals (eg malaria, zika, West Nile, Rift Valley) has typically examined variation in predatory efficiency among species of alien predators1. Unfortunately, this approach has often led to the use of highly invasive alien control agents that subsequently cause unpredictable and deleterious impacts on non-target organisms. The tendency to focus on larger vertebrate control agents such as fish stems from their high per capita impacts on mosquito larvae in controlled situations. Yet these larger predators are inevitably less abundant, less tolerant of environmental extremes, have slower population turnover, poorer dispersal and represent only a tiny proportion of community biomass compared to smaller invertebrate predators. Thus, small invertebrate predators represent genuinely untapped potential for cheap, easy to manage and effective mosquito biocontrol2,3. Optimisation of biocontrol agents is often further achieved by selecting for desired traits among species/populations of putative control agents. What has been entirely ignored, however, is the potential to harness variation in the predatory efficiency among individuals within populations of native predators. The evidence of extremely wide variation in the predatory efficiency of individuals comes from our examination of the per capita feeding rates or ‘functional responses’ of such predators4. Further, we have shown that highly efficient predatory individuals remain so over time4. Thus, there is huge potential to exploit the predatory efficiency of individuals in mosquito biocontrol and ensure subsequent generations continue exerting high predatory pressure on vector populations in the field. We will thus screen a range of native European and African invertebrate species (eg beetles, shrimp, copepods) using this methodology, and proceed to test five core hypotheses:
- Hypothesis 1 (H1): There is significant variation in predatory efficiency among otherwise morphologically identical individual predators within species/populations;
- Hypothesis 2 (H2): Highly efficient predators within populations maintain this high predatory efficiency over time;
- Hypothesis 3 (H3): Individuals showing high predatory efficiency produce offspring with the same predatory characteristics;
- Hypothesis 4 (H4): Individuals showing high predatory efficiency exhibit altered transcriptomic profiles and perturbation of key biological pathways;
- Hypothesis 5 (H5): Individuals with high predatory efficiency will have altered genomic loci that contribute to variation in expression levels of mRNA and modified proteins.
We will initially quantify distributions of individual mosquito predator efficiencies (H1), followed by tests of individual predator consistency over time (H2). Further, for those species for which we establish initial selection lines for predatory efficiency, deriving functional responses will allow us to identify heritability patterns in subsequent generations (H3). Transcriptomic differences between individuals with differing predator efficiencies will be assessed using RNAseq (H4). Spearman correlation analyses and deep machine learning approaches, for example, Logic Forest will be conducted to investigate the relationship between the gene expression signatures and phenotypic measures (especially functional response parameters) linked to increased predator efficiency. The genomic impact will be assessed via high throughput RNA sequencing to assess gene expression of relevant functional isoforms (H5). We will apply computational algorithms that predict the impact of nucleotide or amino acid substitutions on protein structure, expression and function to assess the genetic variants uncovered. This cyclical methodology will allow us to exploit variation among individuals within populations and identify those species with the highest and most consistently heritable functional responses for controlled field trials.
The operationalization of this project will involve engagement with local stakeholders (eg Public Health Agency (PHA), Department of Agriculture, Environment and Rural Affairs (DAERA), Agri-Food and Biosciences Institute (AFBI), NGOs (eg RSPB), health professionals, farmers, vets, community groups) to rapidly disseminate ‘inoculation packs’ of native biocontrol agents to communities for immediate use in drinking and other small anthropogenic water sources; plus provide farmers, schools and other community organisations with education packs of universally-interpretable (ie pictures and flow charts) information on the identification, maintenance and propagation of control agents in the locality. Knowledge exchange and identification/training may be rolled out in other global centres, for example CABI Kenya.
This truly interdisciplinary project will be run under the QUB supervision of the highly experienced Prof Jaimie Dick (behaviour, ecology, invasive species, biocontrol) and Prof Gary Hardiman (genomics, bioinformatics, systems biology) and new start at Aberdeen Dr Thomas Bodey (species interactions, individual specialisation, applied ecology) and with advice from European and Southern African partners (eg Dr Ross Cuthbert, Humboldt Fellow, Kiel and Prof Olaf Weyl, South African Institute for Aquatic Biodiversity). Further, we will specifically collaborate with partners at AFBI, through Dr Archie Murchie (Integrated Pest Management; agreed collaboration), who have interests in surveillance of mosquitoes for West Nile and Zika virus and vector biocontrol. Prof Dick has established a mosquito rearing facility and biosecure laboratory at Queen’s Marine Laboratory (QML) that has seen some 35 publications in biocontrol since 2017, with UK, Indian and South African researchers; Prof Hardiman has 30 years of experience in the areas of computational biology and environmental genomics; Dr Bodey has extensive experience in wildlife management and recently completed a Marie Sklowdoska-Curie Global Fellowship examining the importance of trait variation in invasive species. Full training will be given to the student, however, a background in behaviour/ecology, statistics and with appreciation of genomics will be desirable; the student will also benefit from the extensive QUB/QML/Aberdeen labs/field sites, post-doc and PhD mentoring (including existing QUADRAT students) and bespoke instruction from external advisors and partners.
COVID STATEMENT: this research is ostensibly international, but may be conducted under restrictions in UK laboratories/field sites and hopefully abroad when COVID restrictions allow.
Funding and eligibility information available here.
Jaimie TA Dick
|Profile: Jaimie TA Dick|
Institution: Queen's University, Belfast
Department/School: School of Biological Sciences
|Profile: Thomas Bodey|
Institution: University of Aberdeen
Department/School: School of Biological Sciences
|Profile: Gary Hardiman|
Institution: Queen's University, Belfast
Department/School: School of Biological Sciences
Dr Ross Cuthbert, Humboldt Research Fellow, University of Kiel
Dr Dan Barrios-O’Neill, Leverhulme Research Fellow, University of Exeter
Prof Olaf Weyl, Chief Scientist and DST/NRF Research Chair in Inland Fisheries and Freshwater Ecology, SAIAB
Dr Archie Murchie, AFBI
- Bukhari, T., Takken, W. & Koenraadt, C. J. M. (2013). Biological tools for control of larval stages of malaria vectors: a review. Biocontrol Sci. Technol. 23: 987-1023.
- Shaalan, E. A.-S. & Canyon, D. V. (2009). Aquatic insect predators and mosquito control. Trop. Biomed. 26, 223-261.
- Cuthbert, R.N., Callaghan, A., Sentis, A., Dalal, A. & Dick, J.T.A. (2020). Additive multiple predator effects can reduce mosquito populations. Ecological Entomology, 45: 243-250.
- Alexander, M.E., Dick, J.T.A. & O’Connor, N.E. (2015). Predation in the marine intertidal amphipod Echinogammarus marinus Leach: implications of inter- and intra-individual variation. Journal of Experimental Marine Biology and Ecology, 462: 50-54.
Experimental assessment of predatory efficiencies will utilise advances in ‘functional response’ experimental methods and analyses, which assess key behavioural parameters such as predator attack rates, handling times and maximum feeding rates. New metrics to compare biocontrol agents, such as the Relative Control Metric, developed at QUB by Dick et al, will be used by the student in a comparative assessment of biocontrol agent efficacy. Within this context, understanding the consistency of individual behavioural traits across contexts is also essential, and training in their assessment within an experimental context, and subsequent statistical quantification, will also be provided. For example, JWatcher software will be used for animal behaviour video analyses. These experimental and statistical methods will be supplemented with novel graphics (eg bi- and tri-plots) that Dick at QUB and others have developed recently to display biocontrol agent behaviour and impacts on target prey and their populations. RNAseq will be exploited to compare predatory efficiencies. Gene Ontology term enrichment and pathway topology (PT)-approaches will be used to assess biological impacts. The variants will be analyzed using computational tools that assess if the variant has an effect on protein function. The numbers of variants that cause frame shift terminations, are deleterious, and represent transitions and transversions will be examined. Tools include: i) SIFT (ii) PROVEAN iii) PolyPhen (iv) LRT and (v) phyloP. The student will thus employ a complementary range of research methods to answer key questions from genes to behaviour and population-level impact of putative biocontrol agents of global significance.
Expected Training Provision
Specific training will be in Functional Response and Relative Control Potential metric experimental design, data acquisition, data management, statistical analyses and modelling, plus presentational graphics; multiple packages for these will be used, but in particular ‘R’ statistical/ graphics packages will be employed and training provided. Training will be on-going at QML in the maintenance, husbandry, breeding and security of mosquitoes and their predators, such as copepods, Gammarids and dytiscid beetles. Training in behavioural analyses from video recordings using JWalker will be provided at QUB and UoA. Bioinformatics training in the analysis of RNAseq data, in particular sequence read alignment and QC, differential expression analysis using DEseq2 and systems level analysis will be provided at QUB. Generic training activities associated with QUADRAT will be facilitated, such as field courses and statistical methods, and other bespoke training provide in eg mosquito surveillance in the wild (Dr Archie Murchie, AFBI), biocontrol agent discovery and assessment (Dr Ross Cuthbert), and community engagement and education (Prof Olaf Weyl). Thus, focussed training in all the research methods for this particular project will be provided, plus generic training to improve employability of the student will be ongoing in line with the spirit of the QUADRAT Charter. Other generic training will be in oral and poster conference delivery, report and manuscript preparation, and public/stakeholder engagement through eg maximising social media activity.
Disease transmission and nuisance biting by mosquitoes costs £billions to global economies annually, and severely impacts human/animal health and well-being across almost every region of the world. These threats are increasing with climate change induced range expansions and new invasions by mosquitoes (eg tiger mosquito in Europe). In the UK, there are 34 species of mosquito already, with invasive species that are dangerous disease vectors likely to arrive soon. Thus, research that is directed into developing environmentally friendly methods of mosquito biocontrol has potential to positively impact economies, animal and human health and welfare, replace more costly, damaging and risky strategies (eg chemical control, gene drive technologies) and thus contribute significantly to several UN Sustainable Development Goals (UNSDG). Importantly this project is concerned with examining the efficiency and effectiveness of native species as biocontrol agents. Previous attempts at mosquito biocontrol have frequently used introduced species which have, in turn, turned out to be relatively ineffective at control while also becoming problematic as invasive species in their own right (eg mosquitofish Gambusia). This project will therefore also contribute to efforts within the UNSDG and Aichi Biodiversity Targets to reduce the pathways and rate of introduction of invasive species, further contributing to the preservation of biodiversity. The explicit incorporation into this studentship of education and information dissemination of the research results to frontline areas, such as farming and local communities, means this research could have immense impact on society. The research on mosquito biocontrol will also benefit other vector/animal/human/disease systems, such as midges and associated disease (eg bluetongue), control of pestiferous slugs (eg with marsh flies) and thus provide an exemplar for other projects and research on major disease vectors and their impacts requiring advances in biocontrol research and implementation.
The primary supervisor at QUB/QML will be Prof Jaimie Dick, Prof of Invasion Ecology, Director of Queen’s Marine Laboratory, and developer of functional response and Relative Control Potential metrics as applied to mosquito biocontrol; the QUB second supervisor will be Prof Gary Hardiman, whose genomics and bioinformatics experience complements the whole organism biology of Prof Dick; and the University of Aberdeen supervisor will be Dr Thomas Bodey. This truly interdisciplinary project will blend behaviour, ecology, invasive species, biocontrol, genomics, bioinformatics, systems biology, species interactions, individual specialization and applied ecology. In addition, as per local QUB rules, the student will be appointed a mentor from the QUB academic staff and be closely monitored through Three Month Review, Differentiation (months 9-12) and Annual Progress Review. Further external supervision and advice will be provided from European and Southern African partners (eg Dr Ross Cuthbert, Humboldt Fellow, Kiel and Prof Olaf Weyl, South African Institute for Aquatic Biodiversity). Further, we will specifically collaborate with partners at AFBI, through Dr Archie Murchie (Integrated Pest Management; agreed collaboration), who have interests in surveillance of mosquitoes for West Nile and Zika virus and vector biocontrol. Prof Dick has established a mosquito rearing facility and biosecure laboratory at Queen’s Marine Laboratory (QML) that has seen some 35 publications in biocontrol since 2017, with UK, Indian and South African researchers; Prof Hardiman has 30 years of experience in the areas of computational biology and environmental genomics; Dr Bodey has extensive experience in wildlife management and recently completed a Marie Sklowdoska-Curie Global Fellowship examining the importance of trait variation in invasive species. Full training will be given to the student, however, a background in behaviour/ecology, statistics and with appreciation of genomics will be desirable; the student will also benefit from the extensive QUB/ QML/ Aberdeen labs and field sites, post-doctoral and PhD mentoring and other peer-to-peer support (including from existing QUADRAT student cohorts) and bespoke instruction from external advisors and partners. All research team members from the lead institutions will meet regularly online to assess progress and objectives. Weekly meetings, for example, within the context of academic research groups, will also offer a forum for regular updates and present a forum for troubleshooting. All supervisors will be involved in the drafting of manuscripts and thesis preparation and, based on this contribution, will be co-authors on manuscripts arising from this studentship. Further, the student will be introduced to the extensive academic and other organisations networks developed by the supervisors.
This 42 month studentship will start with a thorough literature review and data mining exercise directed by Dick, Hardiman and Bodey to establish both the specific research directions (eg which target species/potential biocontrol agents to pursue) and utilize existing data on such species to begin training in the behavioural and ecological analyses (functional responses, Relative Control Potential). Simultaneously, the mosquito laboratory/biosecure facility at QML will be up-scaled to provide specimens for pilot experiments and the student trained in animal husbandry, breeding and safe usage in experiments by Dick and resident technicians (Exley, Healey). Surveys for local invertebrate predators in Ireland/Scotland will begin in Year 1 and candidate biocontrol agents selected based on pilot studies with Dick/Bodey. An introduction to and training in genomics (RNA extraction, RNAseq library preparation, RNAseq data analysis, assessment of SNV functional impacts) in Year 1 will be conducted by Hardiman. We envisage functional response experiments to be completed from mid Year 1 across Year 2/3 with Dick/Bodey, with simultaneous data from genomics, systems biology and deep learning analyses from Hardiman. Training as detailed above will ensure rapid data collection, maintenance and management, with statistical tests and modelling instruction provided by all supervisors, plus bespoke courses eg ‘R’. We envisage Year 2 and 3 yielding at least 3 potential biocontrol agents being subject to Hypotheses 1-5, with potential to pilot larger scale mesocosm and field-site trials of mosquito biocontrol agents. The collaboration with AFBI (Dr Archie Murchie) will provide field surveillance research methods and provide an environment of Integrated Pest Management. In Year 2 until end, the student will develop educational and information materials, such as infographics, to help operationalize the work. With a strong emphasis on publication and dissemination, the student will be mentored on manuscript preparation throughout plus conference delivery and networking.