Aphid protective symbionts as unseen drivers of population and community dynamics and the impact for biological control


Agroecology | aphid endosymbionts | biocontrol | multispecies interactionsAgroecology | aphid endosymbionts | biocontrol | multispecies interactions

Aphids are important agricultural pests that feed on plants and transmit devastating plant viruses. Biological control methods are increasingly being used to combat insect pests, either by introducing natural enemies that consume aphids into the environment or managing the surrounding environment to support higher numbers of natural enemies. Our research investigates effects of aphid-suppressing soil bacteria, parasitoid wasps, entomopathogenic fungi, and floral resources for reducing aphid populations on crop plants.

Almost all aphids host an obligate primary bacterial symbiont and many host non-obligate secondary bacterial symbionts. These secondary symbionts can confer wide benefits to the aphid including resistance to natural enemies and abiotic stress, but at a cost to aphid reproductive output. Thus, aphid symbionts can impact aphid population growth, dynamics, and reduce the effectiveness of biological control efforts. Most aphid-symbiont research has been on the model pea aphid, but species-specific outcomes mean the results are often difficult to extrapolate to other aphids. The cereal aphid has been relatively widely studied and tends to host more symbionts than many other studied aphid species, providing a useful system to study aphid symbiont communities.

This project will develop a set of aphid-symbiont lines that can be used in controlled experiments to determine costs and benefits of hosting endosymbionts. We will investigate effects of a variety of natural enemies, and use community mesocosms to examine effects of natural enemy diversity on aphid-symbiont dynamics to compare to field observations. The student will be trained in experimental design and controlled experimental setup, as well as basic microbiology, plant growth, insect handling, and molecular analyses. Data handling and statistical analysis for experimental work will be performed using R statistics. The ideal student will have knowledge of plant-insect interactions and a keen interest in running multi-species insect-focused experiments.


Notes and details of how to apply are available here: https://accedtp.ac.uk/acce-dtp-phd-opportunities-at-university-of-liverpool/.

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Open to students worldwide

Funding information

Funded studentship

NERC ACCE DTP in Ecology and Evolution, programme starts October 2023.
UKRI provide the following funding for 3.5 years:
• Stipend (2022/23 UKRI rate £17,668)
• Tuition Fees at UK fee rate (2022/23 rate £4,596)
• Research support and training grant (RTSG)
Note - UKRI funding only covers UK (Home) fees (£4,596 at 2022/23 rate). A limited number of international fee bursaries will be awarded on a competitive basis. However, if selected International and EU fee rate candidates may need to cover the remaining amount of tuition fees by securing additional funding. International fees for 2022/23 entry were £25,950 (full time) per annum.




Zytynska SE, Tighiouart K, Frago E. (2021) Benefits and costs of hosting facultative symbionts in plant-sucking insects: A meta-analysis. Molecular Ecology 30: 2483-2494
Smee MR, Raines SA, Ferrari J. (2021) Genetic identity and genotype × genotype interactions between symbionts outweigh species level effects in an insect microbiome. The ISME Journal, 15, 2537–2546
Zytynska SE & Meyer ST (2019) Effects of biodiversity in agricultural landscapes on the protective microbiome of insects - a review. Entomologia Experimentalis et Applicata, 167, 2-13.