Using an Antarctic fungus as a wintertime biopesticide

Lead Research Organisation: CAB International
Department Name: International Development (UK)


The problem:
The black vine weevil (BVW) is causing havoc for UK soft fruit growers, with estimated losses for strawberry and blueberry alone of £10 million per annum. Its larvae overwinter in the soil and cause tremendous damage to plant roots, ultimately killing the plant. The damage is so bad in strawberries that new plants are now planted yearly. With the decline in available chemical pesticides, the range of suitable products for BVW control is becoming a cause for concern.

The large pine weevil (PW) is the most serious pest of conifer restoration in the UK and Ireland and is a priority pest of the Forestry Commission. In the absence of control measures some 50% of young trees could be lost across the UK. Figures in 2005 put the potential loss to the British forestry industry at £12 million per year (Torr et al. 2005 Forestry applications, in: Nematodes as biological control agents, CABI Publishing, Wallingford, pp. 281-293). Adult PW overwinter in leaf litter and the upper soil layers and this is the life-stage that a winter-time biopesticide would target.

How are we addressing the problem?
CABI, a not-for-profit research organisation that promotes sustainable agriculture worldwide, and BAS, a polar research institute that applies its expertise globally wherever it can add value, have found a potential answer to protecting British soft fruits and forests by developing a new biopesticide, based on a fungus sourced from the Antarctic. Previous projects have demonstrated, in the laboratory, that the fungus thrives at British winter temperatures (0-10 C) and has insect-killing activity. CABI and BAS are developing a new product to kill BVW and PW while they overwinter in the soil. Current commercial biopesticides for weevils (the majority of which are nematodes) work poorly at temperatures below 10 C, hence over the winter months when these pests are relatively immobile, and therefore at a 'perfect' time to be hit, there are few suitable means of doing so. This project plans to apply the Antarctic fungus to soils in late autumn when soil temperatures start to decline. The fungus will then start to grow as other natural microorganisms will be dormant. It is envisaged that as the fungus grows through the soil it will encounter BVW/PW and kill them. In spring, when native microorganisms exit dormancy, we expect the Antarctic fungus to be outcompeted. In this project soils from around the UK will be collected by AlphaBioControl Ltd, a commercial company promoting the use of sustainable crop protection products. CABI will then examine if the Antarctic fungus can kill BVW and PW in the soils collected. CABI will also determine if the fungus harms earthworms. BAS, who collected the fungus from Antarctica, will carry out ecological studies to determine how the fungus will grow and interact with other microorganisms in UK soils under different temperatures. The outputs of this project will be necessary for obtaining regulatory approval and to provide sufficient evidence to enable the project team, together with a commercial partner such as AlphaBioControl Ltd, to apply for Innovate UK or other industry-led funding for further commercialisation.

Benefit to end-users:
Biopesticide producers will benefit from the opportunity to bring a new product to market which fills a gap in temperate agri-, horti- and silviculture. Producers of soft fruit will benefit by reduced damage to plants. In particular, strawberry growers may not need to re-plant annually, saving labour and material costs, and here will be benefits from a reduced need for emergency chemical intervention. Forestry will benefit as they will have another option to control PW; indeed possibly the only option by 2020, as the chemical pesticides presently in use are being phased out. Furthermore, forestry will not need to restock as many young trees on a yearly basis, if our product is successful.

Planned Impact

The project is building a biological portfolio of a potential novel, cold-active, pest control organism for use in the British winter-time. The key targets within the time frame of the present project are BVW, which causes significant damage to soft fruit plants during late winter and early spring in the UK, and PW, which causes considerable damage in forestry. The project is all about strengthening the portfolio of the Antarctic organism, to facilitate, in the longer-term, its commercialisation and registration as a biological control product.
The project team had submitted a proposal for an 18-month, more ambitious, feasibility study to Innovate UK under the call "Agri-Tech Catalyst Early Stage Feasibility Round 2; Challenge Area: Crop: Pest Control". While the feedback was positive, it raised concerns that the risks were still too substantial to be appropriate for Innovate UK funding; further proof of ecological safety and efficacy was required first. Taking on board the reviewers' comments, the main objective for the project proposed here is to develop a validated efficacious fungal isolate, active at cold temperatures, that has no impact on non-target earthworms and no/negligible impact on native UK soil microbiota, together with foundation data on mass production and a strong exploitation plan for the science generated. Success in achieving the main objective will enable a commercial crop protection company, in collaboration with the project team, to initiate a programme of up-scaling the product development with the long term objective of bringing to market a winter-time pest control product.

Pest control products that are active at colder temperatures would open up a market for the control of a wide range of overwintering insect pests. The project's ultimate aim is to reduce crop losses in UK agriculture, horticulture and silviculture and to reduce the use of chemical pesticides. Reducing yield loss will be of financial benefit to both grower and consumer; reducing chemical inputs will be cleaner and safer for all (for grower, user, consumer and the environment). The innovation of this project will also benefit the wider R&D community working in both crop protection and soil ecology. The project group will present a paper at the 2016 Society of Invertebrate Pathology conference in France (24-28 July), an annual conference which is well attended by both academic peers and industry involved in crop protection. CABI is a member of the International Biocontrol Manufacturers Association (IBMA), an association with some 200 members representing the biocontrol industry in Europe, and regularly attends the IBMA-UK meetings. CABI will use this as an opportunity to inform and update the association on project progress, as and when appropriate. BAS will complete the construction of an Innovation Centre during the lifetime of this project; the progress of the project (subject to confidentiality requirements) will be presented to relevant audiences visiting and using the innovation centre through talks in networking meetings and slides on display screens, giving a wider impact on stakeholders of Antarctic biodiversity from policy, industry, academia and the public.


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Description We investigated the capacity of a fungus from the Antarctic to kill some UK insect pests at cooler temperatures (10°C and 5°C). Our targets were the Black vine weevil and the Large pine weevil, economically important pests of soft fruit and forestry, respectively. Despite repeated attempts to kill the target insect with the fungus, using a variety of strategies, we failed to achieve suitable level to justify moving to a second phase of development (10-15% kill). The fungus was tested at cooler temperatures (5 and 10°C) as per the project remit and used various application strategies, e.g. direct application to the back of the insect and a soil drench. The fungus was also tested against a key non-target, the earthworm, to check for potential side-effects on a beneficial. Tests assessed inoculation onto filter paper and also as a drench in soil, at a range of fungal concentrations. There was no earthworm kill from the soil drench however there was significant earthworm kill at the highest concentration on the filter paper test.
The project assessed the effects of temperature cycles on the growth of the fungus and, whether an application of this non-native fungus could influence the native UK soil fungi. In summary there was no consistent evidence that the test fungus influenced the abundance of native fungi; there were increases and decreases in levels which were potentially related to soil conditions. Finally we investigated the mass-production of our test fungus and established guidelines on shaker speed and duration for optimal liquid culturing of the fungus - if/when anyone was interested in further development or this isolate
Exploitation Route What we were hoping for was good kill of at least one of our target pests at 10°C and also, ideally, at 5°C. However, we failed to get anything near the levels of kill needed to push on with this project into a second phase. We also failed to categorically rule out a lethal effect on beneficial earthworms - which isn't good.
Sectors Agriculture, Food and Drink