Professor Hall's particular interest is the identification and synthesis of natural products involved in the interaction of organisms with each other and with their surroundings. Examples are pheromones of insects, which control many aspects of their behaviour such as mating, feeding and egg-laying and are amongst the most biologically-active compounds known. Other examples are the odours of plants, animals and humans which attract or repel insects and other plant chemicals which affect the behaviour of pests or diseases. Replicating these compounds synthetically requires use of a range of analytical techniques, in order to define their precise chemical structure, and a wide repertoire of synthesis strategies.

While Professor Hall's research group has particular expertise in chemical analysis and synthesis, one of its key strengths is the ability to interact with biologists in the laboratory and field, and with growers and commercial companies. In this way it can ensure the results of its research are taken forward into the field to help manage pests and diseases in an environmentally acceptable, sustainable manner.

Improving Integrated Pest Management in Soft Fruit Crops (2019-2022)

Funding: AHDB SF174
Partners: NIAB EMR, RSK ADAS, Harper Adams University, James Hutton Institute, Russell IPM, BioBest

This project is the latest phase in a rolling programme of research on improving IPM in soft fruit crops funded by the AHDB.  This phase has a number of objectives and those involving NRI include the following.

• In previous phases, NRI and NIAB EMR have developed an approach to control of capsid bugs on strawberry using a repellent in the crop and an attractant outside (Fountain et al. 2021). In this phase, the approach will be adapted for use on raspberry.
• NRI will also be involved in work with ADAS, NIAB EMR and Russell IPM to develop a similar “push-pull” approach to control of western flower thrips, raspberry cane midge and blackberry leaf midge on soft fruit crops using attractants and repellents developed in previous projects.
• NRI and NIAB-EMR have previously developed attractants for hoverflies and in this project these will be tested to help maintain populations of hoverflies in the crop after they have been released for control of early-season aphids on strawberry.

Development and Implementation of Season-Long Control Strategies for Drosophila suzukii in Soft and Tree Fruit (2019-2022)

Funding: AHDB SF145
Partners: NIAB EMR, James Hutton Institute, MicroBiotech

Spotted wing Drosophila, Drosophila, suzukii (SWD), is an invasive pest that has been the most damaging pest on soft fruit, top fruit and grapes since its arrival in the UK in 2013. This project is the latest phase in a rolling programme of research on control of SWD funded by the AHDB.  In this phase, NRI will be particularly involved in exploitation of a powerful repellent for SWD discovered by PhD student, Christina Conroy.  This will be tested in large-scale trials on cherry and raspberry. NRI also provides lures for traps used in season-long monitoring of SWD populations in England and Scotland.

Auto-Dissemination of Entomopathogenic Fungi for Sustainable Control of Spotted Wing Drosophila, An Invasive Pest Threatening the Prosperity of the UK Horticulture Industry (2018-2022)

Funding: Innovate UK 104607
Partners: NIAB EMR, Russell IPM, Berry Gardens Ltd

Spotted wing drosophila, Drosophila suzukii (SWD) is an invasive pest in the UK, and is currently the most important and damaging insect pest in horticultural crops. This project aims to develop a novel device to attract the flies and then infect them with an entomopathogenic fungus which is highly specific against SWD.  The flies can pass the fungus to other flies before dying, greatly enhancing the efficiency of the device. NRI will be particularly involved in developing the attractant to be used in the device.  A lure based on fermentation volatiles has been developed which is now marketed by Russell IPM under the name “SWD DryLure”.

Exploitation of Interspecific Signals to Deter Oviposition by Spotted Wing Drosophila (2019-2022)

Funding: BBSCR IPA (BB/S005994/1)
Partners: NIAB EMR, Berry Gardens, University of Southampton

Spotted wing drosophila, Drosophila suzukii (SWD) is an invasive pest in the UK, and is currently the most important and damaging insect pest in horticultural crops. In previous work, scientists from NIAB EMR working at the University of Southampton showed that SWD was deterred from laying eggs on plates that had previously had D. melanogaster adults mating and laying eggs on them. This project aims to determine the cause of this deterrence which might be developed to deter egg laying by SWD on crops.
It is considered likely that the origin of this deterrence is chemical. NRI is responsible for isolating and identifying candidate chemicals for laboratory and field bioassays at NIAB EMR.

Finding a Solution to Hylobius abietis in Forest Establishment (2020-2022)

Funding: Forest Research; Forests and Lands Scotland
Partners: Forest Research, Sentomol

The pine weevil, Hylobius abietis, is a serious pest of young pine seedlings that is a major constraint in establishing new pine plantations in Scotland and throughout Europe. The aim of the project is to develop a trap that can be used both for monitoring Hylobius and as a device for selective transfer of biocontrol agents to the beetles in a “lure-and-infect” approach. NRI is developing attractants for Hylobius based on components of the volatiles released by host plants and also potential aggregation pheromones produced by the beetles themselves.

Developing Prototype VOC Sensor-Based Products for Determining Soil Health On-Farm (2019-2022)

Funding: Innovate UK 105534
Project Partners: PES Technologies, Small Robot Company Ltd, HL Hutchinson Ltd, NIAB EMR, University of Essex

Healthy soils are vital for food production.  They also provide the largest store of terrestrial carbon, helping to mitigate climate change. Healthy soils are less prone to erosion which exacerbates the damage caused by flooding and the associated economic and human costs.  This project aims to tap into the wealth of information contained in the volatile organic compounds (VOCs) released by soil biota. These have been demonstrated to be excellent indicators of soil biota activity, but their detection and measurement currently requires laboratory-based instrumentation and skilled personnel. In previous work, PES Technologies have developed cheap electronic sensors capable of detecting these VOC’s with the potential to provide virtually real-time, in situ measurements of soil biota activity. In this project data from the sensors will be correlated with a wide range of measurements of soil health. Machine learning will be used to process the data obtained to provide a cloud-based database that can be accessed directly by sensors in the field. NRI scientists are responsible for collecting, analysing and identifying volatiles from a wide range of soil types to provide the data for validating the sensor outputs.

Identification of the Sex Pheromone of Nesidiocoris tenuis, a Damaging Pest of Commercial Tomato (2020-2021)

Funding: AHDB; BBSRC; UoG HEIF
Partners: NIAB-EMR; Thanet Earth; van Iperen BV

Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae) is a tropical mirid bug which is used as a biocontrol agent in protected crops, including tomatoes. Although N. tenuis predates important insect pests, especially whitefly, it also causes damage by feeding on tomato plants, particularly when prey populations decline. In this project the female-produced sex pheromone of N. tenuis was identified and synthesised and shown to attract male bugs. Large-scale trials of mating disruption are in progress in glasshouses in the UK and The Netherlands

Chemical Ecology of Heather Beetle (2020-2021)

Funding: UoG Seedling Fund and UK Heather Trust
Partners: UK Heather Trust; various moorland farmers

Heather Beetle, Lochmaea suturalis, is a widespread and common insect species found across Britain. The larvae and to a lesser extent the adult beetles feed on the leaves of heather plants, stripping them bare and damaging the health of the heather. Periodically, heather beetle populations expand into huge outbreaks, in which millions of beetle grubs can decimate hundreds of hectares of carefully managed heather. This project aims to demonstrate the existence of a pheromone in this species, to identify and synthesise it and to evaluate its potential for monitoring and control of the pest in laboratory and field studes.  To date production of a pheromone by male beetles has been demonstrated and a candidate chemical structure proposed.  Synthesis of this is underway to make material available for laboratory bioassays and field trapping trials.

Pheromones for Row Crop Application (PHERA) (2020-2023)

Funding: Russell IPM/EU Horizon 2020
Partners: Russell IPM (UK), BioPhero (Denmark),. BPF (Netherlands), Fraunhofer (Germany), SEDQ Healthy Crops (Spain), ISCA Europe (France), and Novagrica (Greece)

This EU H2020 project aims to exploit technologies for bio-based production of insect pheromones developed by BioPhero (Denmark) that promise to reduce the cost of these compounds and make widespread use in mating disruption economically feasible.
NRI is contracted by Russell IPM to assay pheromones produced by this technology and to determine release rates of new formulations developed for mating disruption.

Chemical Ecology of Leptoglossus occidentalis (2015-present)

Funding: University of Valladolid, Spain
Partners: University of Valladolid, Spain; University of California Riverside, USA

The Western conifer seed bug, Leptoglossus occidentalis, is an invasive pest from the US in Europe and has become a major problem in cultivation of pine nuts in Spain and Italy. In work on the chemical ecology of this pest by NRI and the University of Valladolid, Spain, male bugs were shown to produce a novel sesquiterpene that caused a strong electrophysiological response in both male and female bugs. The same compound was also shown to be produced by the related L. zonatus, a pest of various fruits and nuts in the southern US.  In collaborative work with Prof Jocelyn Millar, the structure of the sesquiterpene was identified and the synthetic compound is currently being investigated as an attractant in field trapping experiment in Spain and California.

• Hall D.R., Harte S.J., Farman D.I., Ero M, Pokana A. (In review) Aggregation pheromone of the Guam strain of coconut rhinoceros beetle, Oryctes rhinoceros, and revision of stereochemistry, Journal of Chemical Ecology (submitted).
• Arnold, SEJ, Dudenhöffer, J, Fountain, MT, James, KL., Hall, DR, Farman, DI, Wäckers, F & Stevenson, PC. (2021) Bumble bees show an induced preference for flowers when primed with caffeinated nectar and a target floral odour. Current Biology (In press)
• Hall DR, Harte SJ, Bray, DP, Farman, DI, James R, Silva CE, Fountain MT (2021) Hero turned villain: identification of components of the sex pheromone of the tomato bug, Nesidiocoris tenuis. Journal of Chemical Ecology 47:394–405 https://doi.org/10.1007/s10886-021-01270-1
• Fountain MT, Deakin G, Farman D, Hall D, Jay C, Shaw B, Walker A. (2021) An effective “push-pull” control strategy for European tarnished plant bug, Lygus rugulipennis (Heteroptera: Miridae), in strawberry using synthetic semiochemicals. Pest Management Science  DOI: 10.1002/ps.6303
• Mozūraitis R, Hall D, Trandem N, Ralle B, Sigsgaard L, Baroffio C, Fountain M, Cross J, Wibe A, Borg-Karlson A-K (2020) Composition of strawberry floral volatiles and their effects on behavior of strawberry blossom weevil, Anthonomus rubi. J Chem Ecol 46:1069–1081 https://doi.org/10.1007/s10886-020-01221-2
• Lord JS, Lea RS, Allan FK, Byamungu M, Hall DR, Lingley J, Mramba F, Paxton E, Vale GA, Hargrove JW, Morrison LJ, Torr SJ, Auty HK. (2020) Assessing the effect of insecticide-treated cattle on tsetse abundance and trypanosome transmission at the wildlife-livestock interface in Serengeti, Tanzania. PLOS Neglected Tropical Diseases | https://doi.org/10.1371/journal.pntd.0008288 August 25 ,2020
• Sarfo JE, Campbell, CAM and Hall DR. (2020) Effect of sex pheromone blend and lure age on trap catches of cacao mirids in Ghana. Crop Protection https://doi.org/10.1016/j.cropro.2020.105344
• Kihika R, Tchouassi D, Ng'ang'a M, Hall D, Beck J, Torto B (2020) Compounds associated with infection by root-knot nematodes influence the ability of infective juveniles to recognize host plants. J Agric Food Chem  DOI: 10.1021/acs.jafc.0c03386
• Mahot H.C., Mahob R.J., Hall D.R., Arnold S.E.J., Fotso K.A., Membang, G., Ewane, N., Kemga, A., Fiaboe, K.K.M., Bilong B.C.F., Hanna R. (2020) Visual cues from different trap colours affect catches of Sahlbergella singularis (Hemiptera: Miridae) in sex pheromone traps in Cameroon coco plantations. Crop Protection:  127: 104959  https://doi.org/10.1016/j.cropro.2019.104959
• Roberts, J.M., Kundun, J., Rowley, C., Hall, D.R., Shepherd, T., McLaren, R., Johnson, S.N., Karley, A., Pope, T.W. (2019) Electrophysiological and behavioral responses of vine weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae), adults to host plant odors. Journal of Chemical Ecology 45:858-868 https://doi.org/10.1007/s10886-019-01108-x
• Arnold SEJ, Forbes SJ, Hall DR, Farman DI, Bridgemohan P, Spinelli GR, Bray DP, Perry, GB, Grey L, Belmain SR, Stevenson PC.(2019). Floral odors and the interaction between pollinating Ceratopogonid midges and cacao. Journal of Chemical Ecology 45:869-878 https://doi.org/10.1007/s10886-019-01118-9

Lead research group

• Fellow of the Royal Society of Chemistry
• Associate editor, Journal of Chemical Ecology
• Worshipful Company of Fruiterers' prize for Research and Development 2004
• University of Greenwich's prize for Research and Enterprise 2007
• Queen’s Anniversary Prize 2019.

ORCID
https://orcid.org/0000-0002-7887-466X

Research Gate
https://www.researchgate.net/profile/DAvid_Hall111