UK and EU SWD Research Projects. Living Document. Updated: July 2016

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1 UK and EU SWD Research Projects Living Document Updated: July 2016 Introduction One remit of the UK industry SWD Working Group is to monitor recent and current research work being conducted on SWD both in the UK and mainland Europe and keep the industry and research scientists informed as the portfolio of work evolves. This living document has been prepared to summarise the work that the SWD Working Group is currently aware of. The document will be up-dated periodically as new information comes to light. 1. EU Funded Project: DROSKII Project Title: Damage potential of Drosophila suzukii and development of risk management and control measures (DROSKII) WP5: Actions for containment and control of D. suzukii by environmentallyfriendly measures This project was completed in The UK partner within the project was Fera. Scientists at Fera worked on Work Package 5 of the project entitled: A transnational attempt for insight on the damage potential of SWD and the development of risk management and control measures. The Fera scientists who worked on the project included Andrew G S Cuthbertson, Debbie Collins and Howard Bell Key information about the work at Fera Control products selected for investigation Bioassays were performed using formulated insecticide products registered in the UK. The biological agents investigated are all commercially available within the UK. The products tested were: Chemicals: Coragen (chlorantraniliprole not currently approved for use on soft fruit crops in the UK), Movento (spirotetramat not currently approved for use on soft fruit crops in the UK during the year of fruiting), Calypso (thiacloprid), Conserve (spinosad), Pyrethrum 5EC (pyrethrins), Decis Protech (deltamethrin), Neem oil (not currently approved for use on any edible crops in the UK), Tri-Tek (petroleum oil based product, still awaiting UK registration) and a new experimental product (coded: TA2674). 1

2 Biologicals: 2 entomopathogenic fungi: Mycotal (Lecanicillium muscarium currently approved on protected crops of cane fruit, currants, gooseberry and bilberry in the UK), Naturalis (Beauveria bassiana currently approved on protected edible crops in the UK); 3 entomopathogenic nematodes (Steinernema carpocapsae, S. feltiae, S. kraussei - all approved for use on edible crops in the UK). Investigating the dose rate of Coragen (chlorantraniliprole) and TA2674 proved that reducing the dose rate down to a ¼ of the recommended field rate still provided good control of D. suzukii for both chemicals compared to the water control. Investigating impact of entomopathogenic nematodes and fungi on Drosophila suzukii emergence Impact of direct application of products on adult D. suzukii: Spinosad, Coragen and TA2674 were applied directly at standard rates against equal numbers of male and female adult D. suzukii using a Potter Spray tower. Following treatment adult flies were maintained at 25 C and supplied with standard Drosophila medium as a food/moisture source. Mortality was assessed following 24 and 48 hrs. Direct application of all the green products caused higher mortality than the water control. Beauveria bassiana caused significantly more mortality. However, these would not seem efficient in controlling D. suzukii numbers as the next generation of larvae were already coming through in the feeding media 1 week after application. Direct application of Neem onto adult D. suzukii did not cause immediate mortality. However, following 1 week incubation at 25 o C flies succumbed to death and fungi was observed growing on the flies. Neem is known to have chitin disrupting effects and so may have allowed naturally occurring fungi to flourish. Potential for oviposition deterrents for fruit protection to be used: To investigate potential oviposit deterrents, blueberries were first dipped in standard dose rates of Spinosad, Coragen and TA2674. They were then allowed to air dry for 2 hrs. Equal numbers of male and female adult D. suzukii were then introduced to the berries contained within plastic deli-pots. All were maintained in a CE cabinet at 25 C. Mortality of adult flies was assessed over 48 hrs. Berries were maintained at 25 C for a further 10 days before dissection and inspection for presence of larvae/pupae was undertaken. No adult flies developed from any of the three chemical treatments. Larvae, pupae and adults developed in the control berries as expected. 2

3 Conclusions Drosophila suzukii presents a real challenge to the UK horticultural industry. Containment and/or eradication of this pest will prove difficult. From our trials, Spinosad along with chlorantraniliprole (Coragen) and the experimental product TA2674 have shown excellent potential as control agents of D. suzukii when used either as a pre or post-dipping treatment. None of the products tested provided complete mortality following direct application. They all worked better following dipping. The biological agents (fungi and nematodes) caused reductions in population numbers of D. suzukii but are unlikely to control/eradicate populations. However, they will be more easily incorporated into existing invertebrate control programmes compared to conventional crop protection products. Further information and a summary report on DROSKII can be found here. 2. PhD project funded by BBSRC LINK with Oxitec Project Title: Development of an environmental friendly genetic control technology in SWD This work is being undertaken at Institution Oxford University, Department of Zoology. The PhD student is Julia Kidd and the scientists leading the project include Supervisor Dr S Shimeld and Co-supervisor Dr L Alphey Project details The principle employed in this project rely on a process call SIT (sterile insect technique). SIT is a species-specific and environmentally friendly method of pest control. It relies upon the mass rearing, sterilisation and release of large numbers of sterile male insects into the wild. They mate with wild females, leading to a drop in the number of progeny in the next generation. If enough sterile males are released for a sufficient time, the population will collapse. SIT relies on irradiation to sterilise the target pest species but this can have a negative impact on the released insects performance. This and other problems associated with current SIT programmes could be overcome by the use of recombinant DNA methods. Oxitec Ltd is the world leader in developing such approaches and has developed a technique called RIDL (Release of Insects carrying a Dominant Lethal), which uses transgenic technology to overcome limitations of SIT. This project seeks to build on this success in other pest species by developing strains for eventual D. suzukii control in the field. The student will commence with insect transformation for generation and characterisation of RIDL strains of D. suzukii. The student will implement a phased series of incremental tests from laboratory and simulated field conditions to semi-field conditions. 3

4 Important quantifiable properties include nature and position of single insertion events, fluorescence assessment, transgene penetrance and expression pattern, the conditionality of expression, the fecundity of females, egg-to-adult survival rate and flight ability of adults. Mating ability of the RIDL males will be particularly addressed in comparison to both the wild-type background of the strains and to wild males collected from infested fruit. At the same time, rearing experiments will facilitate optimisation of protocols, with a view to developing capacity for future expansion to mass-rearing of D. suzukii. This project started in January 2014 and student Julia Kidd attended the initial meeting of the DROPSA EU funded project along with Martha Koukidou of Oxitec. 3. UK Industry Funded Project at East Malling Research in conjunction with The James Hutton Institute: Project Title: Understanding and developing methods for managing SWD in the UK This is a four year project being funded by both Defra and several fruit industry partners including the AHDB, British Summer Fruits, The East Malling Trust, The Worshipful Company of Fruiterers and CPM Retail. The work, which began in 2013 is being led by Professor Jerry Cross at NIAB EMR. There are five objectives to the project. Objective1: To determine the distribution and seasonal population dynamics of all life stages of SWD in different cropping situations and especially under polytunnel crops on fruit farms in the UK, and investigate its wild hosts and overwintering. This objective is funded by Defra in Year 1. Objective 2: To develop economically and environmentally sustainable treatment and disposal strategies for soft and stone fruit waste to eliminate it as a source of SWD infestation and attraction on fruit farms. Objective 3: To develop and evaluate sampling and attraction methods for quantifying SWD infestations in different soft and stone fruits. Objective 4: To develop a synthetic lure and attract and kill technology for SWD for incorporation into IPM programmes. Objective 5: To obtain evidence for the effectiveness of different plant protection products including biopesticides and for developing an insecticide resistance management strategy for SWD. The complete series of annual reports from this project are available for viewing by clicking here. 4

5 4. DROPSA project (EU funded) Project Title: Strategies to develop effective, innovative and practical approaches to protect major European fruit crops from pests and pathogens This is a European funded project and the UK components of work will be managed by Fera, Imperial College and Oxitec and will focus on spotted wing drosophila. The project began in January The overall project includes the following scientific objectives. Those in red will be conducted by the UK partners. Obective 1: Pathways of introduction of fruit pests and pathogens To determine the means through which quarantine pests and diseases are introduced into the EU and spread across the European fruit sector. Component objectives of this WP are to: Investigate the pathways of introduction of D. suzukii, and the pathogens Pseudomonas syringae pv. actinidiae, Xanthomonas fragariae and X. arboricola pv. pruni into Europe. Evaluate the pathway risk to introduce new pests with fruit movements into Europe. Develop and test methods for qualitative and quantitative commodity pathway risk analysis systems for fruit pests and pathogens. Develop preventive strategies/recommendations against the introduction of other dangerous fruit pests and pathogens. Objective 2: Biology and Ecology of Drosophila suzukii To identify the key mechanisms within the biology and ecology of D. suzukii for the development of sustainable control methods in WP4 and WP6. The component objectives are: To assess the life cycle and environmental requirements of D. suzukii under various climatic conditions. To assess actual and potential host range and study spatial ecology in various environments. To identify natural enemies and other mortality factors. To identify attractive compounds for adult flies. To study the natural dispersion and spread capacity of adult flies. 5

6 Objective 3: Effective and innovative solutions to control Drosophila suzukii To develop effective and innovative solutions to control Drosophila suzukii based on biological data produced in WP 2, transfer of best practices and adaptation of innovative technologies for inclusion in IPM strategies in WP6. The component objectives are: To develop monitoring, mass-trapping, lure & infect methods using semiochemicalbased technologies. To develop protocols based on molecular markers (e.g. LAMP technology) for on-site detection of D. suzukii in traps or plant material (DLO, FERA). To evaluate natural enemies identified in WP2 for the biological control of D. suzukii. To test for effective control utilising existing chemical compounds for inclusion in IPM. To develop sterile insect techniques to reduce D. suzukii populations. To evaluate the potential of new mode of action compounds as alternative solutions in D. suzukii control. Objective 4: Practical solutions for control To develop innovative, practical, preventative and integrated control solutions for quarantine fruit pests and diseases, utilising current control strategies and those developed in WP 2, 3, 4 and 5, with an emphasis on the prevention of D. suzukii and diseases that infect crops. Integrated strategies (IPM) for the major economic fruit crops in Europe will be combined, concentrating on kiwifruit, strawberry, peach, cherry and grapes. This will involve ex-ante economic assessments from WP 7 and the pathways and impact analyses developed in WP1. Component objectives are: To develop decision support (DSS) and forecasting systems. To develop cultural management strategies. To optimise IPM strategies under commercial field conditions. 6

7 5. AHDB Funded Studentship Project Title: Searching for Viral Pathogens for SWD This studentship project is being led by the University of Edinburgh University in conjunction with NIAB EMR. The work began in autumn Project details This project will identify, isolate, and characterise viruses suitable for control of SWD. Because SWD is closely related to the laboratory model D. melanogaster, this work will capitalise on our knowledge of melanogaster genetics, immunity, and parasitology. This will require: Objective 1: Detection of novel viruses using a high-throughput metagenomic approach. Scientists have used this approach successfully to identify multiple new viruses from D. melanogaster, including a DNA Nudivirus. Objective 2: The isolation of viruses capable of infecting SWD, either from SWD or from amongst viral sequences we have identified in other Drosophila (including the Nudivirus). Objective 3: The characterisation of viral pathology in SWD, for example: dosage curves, rates of mortality, transmission and variation for resistance. Progress to date To date, cutting edge genetic techniques have been used to sequence the genetic material of all pathogens infecting D. suzukii. Through the Edinburgh University lab s expertise in the study of Drosophila viruses, a selection of viruses present in wild D. suzukii have been identified. Some viruses discovered appear to be very closely related to the viruses found in D. melanogaster. Others however, seem to be unique to D. suzukii and new to science. Through a technique called serial passage the project has confirmed that an extract containing only the viruses of a large pool of wild flies has a lethal effect on D. suzukii in the lab. The work is currently in the process of identifying which viruses cause these lethal effects and isolating pure viral isolates for further experimentation. Further sequencing is now underway for another large sample of flies caught in

8 6. AHDB Funded Research Project SF 153 Project Title: Selection of strains of predatory mites that can survive applications of insecticides required for SWD control Project background and details Predatory mites are widely used in soft fruit production to control a range of damaging pests, such as spider mites and thrips. For success the range of crop protection products used in the crop needs to be carefully chosen to allow survival of sufficient predators. However, some of the most successful crop protection products recommended for use against SWD include the synthetic pyrethroids and spinosad. Predatory mites are not resistant to these compounds, so their use to control SWD is likely to disrupt biocontrol of other pests. If predatory mites could be selected for resistance to these insecticides their use could be integrated into the programme for control of SWD. This project, which is being managed by David Buss at East Malling Research, aims therefore to identify suitable predatory mite species, with respect to their prey range, and to develop resistant populations suitable for bio control. Progress to date Amblyseius andersoni was selected as the initial subject as it gives good control of spider mites and is considered a native species for authorisation for any subsequent use on non-glasshouse crops. Commercially available A. andersoni were obtained and assessed for their susceptibility to spinosad (Tracer) and lambda-cyhalothrin (Hallmark). They were found to be highly susceptible to lambda-cyhalothrin, but less so to spinosad and so selection commenced with spinosad. A population of selected mites was obtained and results indicated that tolerance to spinosad had increased. Another predatory mite species, Neoseiulus cucumeris, again a widely used native species, was treated in the same way to derive a population of spinosad tolerant mites. Later research focused on developing a method to increase the selected populations to derive large numbers for future work. This work is ongoing. 8

9 7. Defra Funded Research Project Project Title: Exploration of winter and spring habitat preferences of Drosophila suzukii: a new approach to control a new invasive pest. Background and aim of the project This project is being led by NIAB EMR. The aim of this project is to investigate the winter and spring habitat preferences of Drosophila suzukii in its winter form. The responses of D. suzukii winter morphs to known attractants and volatiles from favoured host plants will also be investigated to identify compounds that might be used to increase further the attractiveness of current lures to the winter morphs. The outputs will provide data on the feasibility of developing a winter/spring mass trapping approach as a new tool in the management of this pest. This could reduce D. suzukii populations entering crops from their overwintering sites, thus delaying or alleviating the onset of fruit attack, especially in cherry orchards. 9

10 8. AHDB Funded Studentship Project Title: Enhancing control of the soft- and stone- fruit pest Drosophila suzukii (Spotted Wing Drosophila) by exploiting its activity patterns in the field. This studentship project is being led by the University of Southampton in conjunction with NIAB EMR. The work began in autumn Project details This project will identify the daily and seasonal behaviour rhythms of Drosophila suzukii (spotted wing drosophila, SWD) in order to exploit its behaviour for future pest control in UK fruit crops. It will determine the environmental factors that affect behaviour and how these interact with pesticide efficacy and trapping. The project will be a novel and exciting new collaboration between the University of Southampton and East Malling Research. The student will gain skills in crop husbandry, chronophysiology, ecology, pest management, and data analyses and interpretation. D. suzukii is currently a seriously damaging pest of soft- and stone- fruit crops. In 2014 fruit picking in some crops had to cease as the pest became too abundant in the fruits. To achieve more efficient management of this newly invasive pest it will be useful to predict the daily and seasonal fluctuations in behaviour to target strategies for more effective control. The proposed project will test daily patterns of activity, feeding and egg laying under spring, mid-summer and autumn conditions simulated in the laboratory. Further laboratory experiments will identify the contribution of light, temperature, humidity and internal timekeeping mechanisms to these observed rhythms. Parallel field trapping experiments will verify D. suzukii behaviour patterns in vulnerable crops and in wild areas where D. suzukii is known to overwinter. Once these parameters are understood the student will examine the vulnerability of the various stages to pesticide applications and how pesticides interact with field temperatures and D. suzukii behaviour, throughout the day, in their efficacy. Finally, grower recommendations regarding the likely activity and control of D. suzukii based on time of year, time of day, and weather conditions will be made. 10