Chafers, Leatherjackets and Bird damage

 

Hi All,

 

Some of you may have noticed it’s that time of year again when we are seeing bird damage on various spots. This is being caused by grubs within the soil and the birds are feeding on these grubs.

This hasn’t been a big issue until recent years. The withdrawal of the chemicals used to control these grubs in 2016 with a use up date of 2017 has meant we are now seeing damage increase year on year. The damage sustained last year wasn’t seen by most due to the lockdowns.

Interestingly we are seeing a lot more chafer grubs now. We hadn’t seen any on the course until 2019, when Graham Hastie and I found two on the 5^th hole. Fast forward to 2022 and this has been the dominate species we have found in the fairways over last two months.

We have always had issues with Leatherjackets and have tried our best to mitigate the issues these can cause but that is changing and we as an industry are learning more about both Leatherjacket and Chafer grubs.

Chafer grubs under the 12^th fairway above at stage 2 of the life cycle

Why is this happening now?

The effective chemical options we had are now long gone. We have one new chemical which at the moment is only being issued on an emergency licence one year at a time. This means we never know if it is going to be approved for the following year.

Once an emergency licence is approved we can only spray Greens, Tees and 10% of fairways. The amount we can purchase is limited by the government, we have to fill out stewardship forms and record the application. We are also only allowed to spray for one the species in one year. Unfortunately we now have both species meaning we will need to address which one we think is going to be the prominent one for the following year as the timings of the grub’s life cycles are completely different. You can see this isn’t easy and if I am honest the effectiveness of the new chemical is about 60% compared to the old chemistry and is ten times the cost. It’s also worth noting the rates of application in the UK for the chemical is 50% of the rate in the USA.  

Leatherjackets off one green

 

Year on year the populations are growing at such a rate that damage will increase, For example one Leatherjacket can lay up to 400 eggs before they die. The drive from Government is to be so green now and the EU restriction’s which the government and the House of Lords has agreed to wont be overturned. We have already seen the Sugar beet market in the UK collapse over this issue. The irony is, we are now importing all of our sugar from countries that don’t have these restrictions! 

Leatherjacket Husks after Cranefly have left eggs inserted into green

What are we doing and what’s our options?

 

Apart from applying Acelepryn insecticide described above only on limited surfaces we will also be applying Nematodes as part of our strategy.

This is biological option but again data is limited about how effective these can be and the timing has to be perfect.

·         Soil temperatures must be 14 degrees at one point during the day and it cannot drop below 6 degrees or the Nematodes will die.

·         We need to aerate the greens prior to application

·         Water the greens before we apply, this helps the nematodes move over the surface and down the aeration holes.

·         It cannot be sprayed in direct sunlight as UV kills the nematodes

·         All the filters on the sprayer must be removed

·         It must be sprayed below 8 bar pressure on the sprayer

·         The Nematode packs must be mixed prior to adding to the sprayer. This takes five minutes per pack and 32 packs are needed

·         The greens must then be watered after application

·         Greens must be kept moist for three weeks after application

 

Both of these are our only proactive options available.

The other methods will be more reactive. You may have seen silage sheets being used at other clubs in the last year. This method requires us to cover an entire green from the afternoon, overnight and then this is taken off in the morning. This brings the LeatherJackets to the surface and as they believe they are still under ground. Once the sheet is removed it’s a race against time to either blow or cut them up before they start to head back down into the soil and this is only a few minutes.

This maybe a strategy we need to put in place and you the golfers will need to be aware that this is happening. This isn’t something we can plan too much in advance. When we start to see the damage to the surfaces we will need to react quickly. Remember the grubs survive by eating the roots of the grass plant. They can eat up to 60% of the root on each plant causing huge stress or even death of the grass species.  We will inform members by email on the day if this is needed.

A temporary hole will placed short of the green to play too but I must stress this is a last resort and we hope that this won’t be an issue we need to face but I wanted you to know this is an option we may require to reduce the populations down quickly and save the surfaces. 

Silage sheets being used for Leatherjackets control

Bird damage

Regarding the bird damage. We have been trying to encourage the birds to leave the area and are now looking at bird scarer’s, birds of prey and long term we will be looking at increasing our Starling bird boxes. The starlings eat the grubs in the same way but their beaks are so small that there is little damage.

The damaged caused looks awful but it can be repaired and luckily enough we now have the new irrigation system which will help aid recovery. We can soil and seed into these areas knowing we can now water the area. Which will help germination and speed up recovery.

Bird Damage on the 15^th

Going forward

I think our mentality for this issue will need to change from ‘zero damage’, which is now almost impossible to ‘how quick can we recover’.

This is the mentality that the Scandinavian countries have every year when they come out from the snow cover on the course.

We must continue our strategies laid out above, we need to carryout trials and stay up to date with the industry findings because I can assure you we are not the only ones in this situation and the entire industry are looking at this. Time and patience will be needed but I am sure as an industry we will get a better understanding of these species and we will overcome this. 

It is worrying and it is frustrating but it is grass and we can get recovery. Things might not always be perfect but let’s face it, we have 140 golfers a day playing on the course taking divots out of the surfaces and we get them back. This is just another thing we need to learn to recover from! 

The new irrigation system will help aid recovery of the affected areas

I hope this information gives you a little understanding of the challenges we face as an industry. Any questions please feel free to ask me when you see me.

 Regards

Matt