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Leatherjacket Q&A: Summary

MA = Minshad Ansari: Bionema CEO and leading biopesticide technology developer

PC = Peter Corbett: Business Development Manager at Rigby Taylor and industry expert

MT = Mark Tucker: Head Greenkeeper at Neath Golf Course

Leatherjackets have been a real problem in turf sectors following a mild winter, with many golf courses experiencing heavy infestations across the UK. The problem is two-fold; leatherjackets feast on the roots of grass leaving large bare patches on the surface, while passing wildlife will tear up the turf for a quick snack which can be very costly to repair. It was for this reason, we got together three experts in their respective fields to discuss the leatherjacket problem faced around the UK – and answer some of your questions to help you get ahead. Take a read.

Q1: After a mild winter, what challenges have sectors involved in turf management faced?

PC: Having come from a very wet autumn, and then no rain for 6 weeks, turf has experienced extreme conditions. Climate change is creating challenges when managing turf surfaces, and coupled with Covid-19, it has been difficult for companies.

MT: Leatherjacket larvae this time last year was ridiculous, 150+ per square metre. We decided to try nematodes last year with success on our approaches. This year, our greens have suffered; larvae are 80+ per square metre. These areas were not treated with nematodes.

Q2: I have seen a lot of leatherjackets early in the morning on the surface of my greens moving around. Why is this happening?

MA: Leatherjackets are becoming active in the spring season, so when the weather becomes warmer, they become more active. Why it’s happening is due to a high population; too many larvae under the soil come to the surface for feeding.

PC: Understanding the life cycle and how pests behave and how they modify their behaviour is a key part to dealing with pests. If we don’t understand how a pest is behaving, we don’t know how to treat them. High, dense populations of pests like leatherjacket will behave differently to optimal lower populations.

Q3: How can people identify that they have a problem before the damage is done?

MA: Crucial question; sampling is the way forward. Turf professionals should be checking the turf and soil samples in spring and autumn, when they will find the larvae underneath. The best way to monitor is by sampling, taking a soil plug or core, as there are no traps available for larvae yet so monitoring larval population is paramount.

PC: There should be threshold levels set by industry standards so that people are aware of what needs treating and that can be used to help golf courses, for example, monitor their pests.

MA: There are different thresholds established by a few people based on limited information, but larval population should not be exceeding >30 per square metre, higher than that leads to fast increase in population. Keep the population below the threshold to reduce the turf infestation.

MT: The biggest problem was in 2019. Due to the weather, roots were compromised and the turf suffered worse.

PC:  If the turf isn’t under stress, then the turf can cope with more pests. Essentially, it comes down to good management practises and keeping the turf healthy.

MA: Setting a threshold for leatherjacket does help with turf improvement and a healthy turf can fight against pests and disease or can tolerate low populations.

Q4: Follow-up to Q3 – When should people be sampling their turf through the year?

MA: I would recommend people keep records and sample their turf every couple of months and keep records of these results. Rigorous soil sampling and pest identification will help to design a control programme if needed.

PC: The greenkeepers are key. They know when things are right, and things are wrong. There are things we can do to help but we cannot replace your observational skills, and this means keeping records. Keeping records is crucial, and active data capture is a critical point going forward for any solution we are trying to achieve.

MA: When I visited Neath Golf Club, their records were impeccable, and they had a good idea where the problems were. Sometimes the dilemma is finding a population and thinking they are ok but understanding the threshold per square metre is essential.

Q5: Sheets have helped drive leatherjackets to the surface, but this isn’t practical for when we reopen. Is there any way of driving leatherjackets to the surface without using sheets?

MA: Early in the morning, after 4 am, leatherjackets tend to come to greens and as soon as the sun heats the grass they start going back, however, a few of them left on the grass can be eaten by birds, causing further turf damage. There is no attractant available in the market for larvae or adults! So, what you want to do is drive the nematodes down to the leatherjackets – this can be done using a biocompatible wetting agent, which we at Bionema have developed for fast action.

Q 6: Are pest problems linked to the health of my turf?

PC: Generally, if turf is under stress, then whatever is attacking it, you will find the symptoms of the disease or pest will be worse. The further we can go in getting the agronomy right, keeping the crop healthy and keeping the nutrient levels and water levels right, the better the turf can support itself.

Q7: What controls are out there for leatherjacket and how easy are they to use?

MA: For leatherjackets, there are no other biological controls apart from beneficial nematodes in the UK. These have been commercialised and sold to different sectors. The biggest problem in turf and amenity is application; when we sort this out, we will have better control.

The problem is just putting the nematodes in the tank and spraying it. When they land on the grass, they try to penetrate the turf thatch which is a big obstacle and exposure to UV light for more can be very harmful to the nematodes.

Soil aeration and soil being wet is imperative, and I promise that by doing this, it will really help you get great results.

Q8: How did you get on with using the nematodes at Neath Golf Course?

MT: I was very sceptical initially, as nematodes have had a bad press. When Minshad came to see us last year, we decided to give it a go, when larvae were up to over 180 per square metre.

We applied the first nematodes in late April, and with the knowledge Minshad gave us, was so simple. Two weeks later we applied again – it’s just so simple but must be done correctly. Moisture is crucially important. A second application in September helped to reduce leatherjackets further.

PC: There is no doubt that if a nematode gets in contact with the leatherjacket, it will work. This is the same issue for chemicals too, water is critical.

Q9: I’ve mainly used chemicals, but many are becoming unavailable. Are biological methods as effective?

PC: It’s not straight forward. Up to now, conventional products have been effective for most pest species. But for good scientific and ecological reasons a number are now not available or will become unavailable. A new product coming into the market will be very difficult to come through the registration process, whereas biological products are a lot easier; naturally occurring nematodes are better.

Nematodes have been around for a long time; generally, not as effective as conventional products. BUT this comes to how you are using them, and what you are comparing it to.

MA: The pest problems experienced in the horticulture sector, with fruits and vegetables, are driving biological products. The turf industry is still a bit reluctant to go down this path, but with the chemicals they used to use, many banned in 2016, there is now a solution in biological products.  We, as a company, are trying to help educate Greenkeepers about how and when to use the nematodes. When something is alive, there are requirements for storage and transportation… but, the effort is worth it. You don’t need to use the same amount in the following years as nematodes can reproduce on killed larvae up to 50,000-100,000. Other products could have a detrimental effect on nematodes or other microbial products. It’s important to understand that the combination of nematodes and other products could have alternative aims.

Q10: If applying your nematodes, how can we measure them in the soil? And can these be cultured in with a compost tea brew before application?

MA: Yes, there can be other nematodes in the same field. Taking a soil sample and baiting with Galleria larvae or any other insect larvae can be done; if a nematode is present in the soil, the killed larvae will turn yellow or red. Yes, nematodes can be mixed with tea compost or chemicals, but their compatibility should be checked before.

Q11: One the one hand, chemicals are being phased out due to their impact on the environment and, in part, insect populations. On the other, people need to manage their land for their businesses and to make a living. How can these opposing stances be brought together?

MA: Integrated pest management (or integrated turf management) where turf practitioners are being advised not to just use a single product. In horticulture, this has been used for a while – introducing an insect before the chemical. When managed properly and being aware of how these products interact, you can judge the application time to ensure minimal negative interactions for an effective control programme. In turf, there are mainly bioinsecticides and bio fungicides. Despite a slightly higher cost, they can offer long-term control if used correctly.

PC: From a chemical background, I can’t dispute the science. However, essentially if we want to control something, we will have to kill it. Going forwards, we want to ensure the methods we use don’t have other negative effects on the environment. While greenkeepers need to manage their land, they need to take a wider approach now and individual ‘one-size-fits-all’ products simply aren’t going to be there. So, integrating turf management approaches will be key going forward to produce a healthy turf for the end-user.

Q12: Mark, how much attention is paid to beneficial insects and environmental concerns when planning turf management on your golf course?

MT: It’s huge and it has changed. When golfed boomed in the late 90’s, the approach was get out and spray with anything to get a good surface, but the mindset of greenkeepers has changed considerably over the last 10 years. There is more interest in science and greenskeepers are understanding the issues a lot more. Looking at BTME, science is probably 30% of management courses. With chemicals being taken away from us, we have to be open minded and look at alternatives that are sustainable and biologicals are the way forward.

PC: The key is learning how to use the products in the right way, which is a challenge considering the complex ecosystem we are dealing with. The industry also needs to conduct trials to benefit everyone in the future.

MT: In the old days you would go and chuck 40% nitrogen fertiliser on and see immediate great results, but these days it is more about building up a healthy soil and looking at soil biology. Stick to your plan, stick to your goals, and this can be hard if you don’t get immediate results – but trust the science that you will see the results.

PC: Again, helping educate the greenkeepers is important going forward. Letting end users as golfers be more aware, we need to educate them to let them know that there are certain things are outside your control – dealing with a huge natural ecosystem and limited natural tools to play with.

Q13: What integrated pest methods are available and how can we involve those who will use this?

MA: Integrated pest management is quite old, and factors in cultural, physical, chemical and biological considerations – and monitoring for pests and diseases.  Monitoring pests and disease aren’t happening at most golf courses now, as chemical methods were quite effective. As these have gone and large pest populations are booming, we need to monitor as this is paramount and part of integration.

It is very much education, and based on my experience, at the moment companies are based more on sales than education. This will help integrate different products in the same soil. I’m not aware of any other company in the sector providing free education and training products like we do at Bionema, as we make it a priority to educate to give a better knowledge of how we can be a part of integrated pest management solution.

Q14: Golf course patches are getting torn up and repairs are becoming very expensive. What can I do?

PC: Identify the problem; the level of problem can range from badger to pheasants, so identify what is causing the problem and then look at what methods can be used to mitigate the problem. I guess it is a predator, such as a badger, looking for a meal – grubs or larvae. Of course, managing a badger is a different issue to managing crows and rooks which can peck at turf.

MT: Remove the food source and you will stop them digging what they are trying to dig for.

Q15: Can nematodes damage turf?

MA: Yes. There are many different types of nematode, one of which is the plant parasitic nematode which causes very serious turf damage, 20-80% economic damage has been reported. These plant parasitic nematodes are very difficult to control but there are one or two bionematicide products are available. Maintaining healthy turf can be a good idea to reduce stress.

PC: The services are there for sampling and analysis, which Rigby Taylor alongside other companies can offer. When you find the problem, you can find the solution. Within nematode genera, there are a huge number of nematode species. If you take the mass of all the nematodes on the earth surface, it is greater than any other group.

MA: Plant-parasite nematodes feed from inside and outside the root, but when they enter inside – very difficult to control. The plant will get stressed and start to show symptoms. Soil sampling again comes here again.

Q16: Leatherjackets all but went away last year after using nematodes, do I need to continue to reapply nematodes more the once?

MA: Its normal that after you apply a product, like nematodes, you want to see an immediate effect. Its very much depends on the start point, if population is very high or above the threshold then you need two application per year and continue for 3 years to reduce the population to below the threshold.  In year one, you will see 50-60% control, second year 80%, third year over 90%.

Q17: Looking forward, what are the biggest challenges to turf management?

PC: Number of challenges, across the spectrum. One of the biggest concerns is eutrophication – the amount of nutrients entering water courses from chemicals applied on land. The industry will have to work on the utilisation of the CORRECT nutrients. While in most sectors like agriculture, earthworms are very beneficial. For turf, this a huge challenge going forward. Also, managing increasing pest populations spotting these in advance – such as leatherjacket and chafer grubs – will be a challenge. Finally, the level of disease within the greens as the tool set that we have is reduced.

MA: This is a huge question with wide scope. Keeping an eye out for new pests and diseases which impact turf will be important. Also, the removal of chemical pesticides has created a vacuum in the industry for pest control and learning the new measures. Hats off to all greenkeepers, as they do a tremendous job!

Q18: During lockdown, do you manage turf differently?

MT: Yes, a lot of less staff on the course. We are leaving the grass a bit longer on the greens and tees as we don’t have to prepare the surfaces for playing; we are managing stress levels on the course, so we don’t need to worry about that but working within the current guidelines. It’s just about keeping the stress off the course.

A note for our listeners:

MA: The pest problem is increasing so we must wake up now; my message to greenkeepers is to do soil sampling and check the population before it’s become too serious – keep the leatherjackets population below 30 per square meter.

PC: Look out and assess the areas where the issue is, identify pest population levels and make records then asses the issue against the threshold. If you need to do something about it, make sure you do so before the next generation emerges.

Q19: How can people access more information?

MA: Find out more on our Bionema website, we have free training on our website and what we can do to help you. Follow our twitter account, @Bionema, feel free to ask us a question or DM us. Bionema released White Paper to Turf and Spore, first in the industry. Not a large document, very fine information and very informative guide for turf professionals.

PC: Understanding the science is the most helpful and looking at the experts and what they are telling you is the crucial part; understanding and education.

MT: Anyone can email me for the grassroots perspective of nematode application at Neath Golf Club. Follow us on twitter @NeathGolfClub.

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