The leatherjacket and chafer fine turf threat at
Barton-on-Sea Golf Club and nationwide
Insect pests of fine turf have been problematic in the UK for many years. However, until recently, controlling their behaviour and the subsequent behaviour of birds and mammals feeding on them, has been reasonably straightforward to achieve.
Although there were warnings of likely changes to pesticide legislation in recent years, industry practice continued as normal. It was common for greenkeeping teams to treat prone and valuable areas with insecticides, such as chlorpyriphos and imidacloprid, at the appropriate time of year.
Both products were very effective insecticides. A single application would ordinarily eliminate any problems a greenkeeper was likely to see - from grass and root feeding insect grubs - for up to twelve months.
However, now both active ingredients have been recently withdrawn from use, in amenity turf, the impact leatherjacket and chafer grubs have on fine turf has been steadily growing.
Leatherjackets are the grubs/larvae of the crane fly or ‘daddy long legs’.
Adults emerge in August and September.
Females do not move far from emergence and mating occurs quickly, with eggs being laid within 32 hours of emergence.
Up to 400 eggs are laid, with six or fewer eggs being laid at one spot.
Eggs are dark brown and are laid into the soil at the base of grass stems.
Eggs hatch around 14 days later and larvae start to feed.
Leatherjackets feed on roots but can often be found on the surface on damp evenings feeding on leaves.
The leatherjackets are grey/brown to green/grey in colour, legless maggots with no distinct head capsule.
The first stage larvae are around 0.3cm long growing to 1cm after approximately one month (around November in the UK) and reaching 2.5–4cm after the feeding period in spring.
Larvae then move down the soil profile in the summer to pupate. The pupae wriggle up the soil profile with the help of backward pointing spines and push themselves partly above the surface for the adult to emerge.
Damage can range from no visible symptoms to complete sward destruction. Most turfgrass will harbour a low number of leatherjackets and show no adverse effects.
The amount of damage is related to the number of leatherjackets present and the condition of the grass. In golf turf, a threshold of 16 leatherjackets m2 has been proposed for insecticidal application.
Other factors to be considered include:
Turfgrass that is already under stress will be more severely damaged by leatherjackets.
Shallow rooted grass plants find it more difficult to recover from attack.
During the winter, when turf is only growing slowly (or not at all), leatherjackets may still be actively feeding.
Turf may have difficulty in recovering in a period when growth is low or has ceased.
The activity of birds searching for the grubs also disrupts the turf surface with tufts of grass left loose and holes opened in the sward.
Badgers may also cause damage to the turf surface searching for leatherjackets.
Chafers or white grubs are the larvae of the chafer beetle, of which there are several different types.
The garden chafer is the most abundant species.
The adult is around 9mm long with brown wing cases and a bottle green head.
The larvae grow to around 18mm.
It has a one-year lifecycle.
Adults are traditionally found in late May or June. However, this depends on spring temperatures.
Adults emerge over a period of approximately 10 days, flying between 10.00am and 12.00am in sunny conditions.
Males may swarm looking for emerging females.
Females mate as soon as they emerge and burrow back into the soil to lay eggs.
The eggs are laid in groups of two to six eggs (a total of 10–50 are laid) about 1 cm below the soil surface. This often results in a localised build-up of the chafer population.
The female then emerges again and feeds on trees and shrubs before flying to another site to lay more eggs.
The eggs hatch four to five weeks later and the larvae begin to feed on roots.
The grubs grow through three instars.
The third instar digs deeper into the soil to hibernate. As no more feeding will occur between hibernation and pupation, garden chafer larvae do not cause grass damage in the spring.
The grubs pupate (pupae can be found in April) and adults emerge the following summer.
Cockchafer and summer chafer have two to three-year lifecycles, respectively. Therefore, larvae of these species may cause damage in spring as soil temperatures increase and larvae resume feeding.
Damage to the turf can occur directly as a result of high numbers of grubs feeding on root stock and turf. Or it can come as a result of birds and mammals hunting for the grubs as a food source. It is not difficult to imagine the damage that can be caused to fine turf areas in these circumstances and the images below illustrate some of the turf scenarios seen this spring.
Efforts continue to be made by clubs and their advisors to make the golfing population aware of the changes in product availability and the likely impact this could have on golf course conditioning.
Biological treatments have a low success rate. Other avenues of progress are currently under investigation, such as newer and safer insecticides and trying to make biological control easier to implement, but these developments need to be supported scientifically and financially.
At this moment, the turf industry appears vulnerable and this means that a host venue for a major sporting event could be impacted by an insect-based problem. In the worst-case scenario, this could have notable implications for the event concerned and mean that surface quality could be compromised for some time.
Currently, more cultural practices include: more aeration, scarification and overfeeding to increase plant health and outcompete the pests.
Acidifying turf using ammonium sulphate, citric acid and chitosan all helps in the process of suppressing the problem; however, does not solve it.
Long term, industry bodies will have to come up with a solution to ensure the future of all sports turf.
Weather conditions have set new records seeing the driest spring on record, which also confirms the amount of water disturbed through the irrigation system this year. Previously in 2019, a total of 10,230 cubic meters was used over the course of the year. So far this year, 5502 cubic meters have been used with four months left of the season.
During the end of May beginning of June the course suffered several days without a fully functioning irrigation system. The irrigation pump station suffered a pressure switch failure followed by a main pump failure. This led to the greens not seeing any water for 4 nights. Two of the nights were back to back during a hot spell.
Greens and tees are coming back on track since the pump failure during the previous hot spell.
Liquid applications of Nitrogen, Potassium, Magnesium, seaweed, growth regulator and wetting agents have been applied daily.
Greens and tees have been lightly scarified to thin out and remove lateral growth. Once the current hot spell passes, greens will see a more vigorous scarification (verti-cut), plus another sand dressing in preparation for competition golf.
The current height of cut stands at 3.75 millimetres down from 4.5 millimetres, with some leeway for the Club Championships.
Hand watering is now occurring daily to areas with poor irrigation coverage.
New tees from the previous winter construction are reaching the normal height of cut. Soon they will merge with all existing tees regarding general maintenance.
Jobs ongoing: hedge work around the course either in front of tees or along pathways.
Constant attention to sprinkler heads to maximise efficiency and using the rain train on certain fairways. The rain train (travelling sprinkler) unfortunately had to come off the course during the pump station breakdown. Ragwort clearance and weeding paths. Strimming bunkers. Divots on tees. Course furniture is making a steady return in line with England Golf. This includes hazard markers, fairway markers, 150 posts, and traffic posts. In planning, on top of the above, Greens will receive a pencil tine aeration to a depth of 8 inches to relieve tension.
Finally, Amy is now slowly taking over the role of spraying technician due to only the Course Manager holding a licence. Amy is making great progress towards a test later in the year.
Since November continuous rainfall has been helpful for new turf, however not for earthworks, work has continued regardless.
December rainfall 148mm / 5.8 inches. Days closed 4, Days carrying only 11, Days with no buggies 23.
Progress with renovation work is still ahead of schedule. All 14 new bunkers are now lined, drains installed and ready for new sand. There is a total of 100 tonnes to go out which also covers a spring top up to existing bunkers for the season ahead.
John Deere from Blashford are kindly lending a six series loading tractor during the last week of January allowing new sand to go out. Also, during this week, the tractor will be used to load top-dressing to lightly sand the greens, another task that cannot be achieved without this piece of machinery.
Fence work within the course is now complete. This includes 5 Stroller white tee and 2 Needles pond. Fence work along the cliff top will commence once all tee work is complete.
Tee levelling is making good progress, 8 Needles white tee is now level and turfed.
2 Needles white tee and 7 Stroller red tee are levelled ready for turf.
5 Stroller white and red tees are close to completion ready for turf, Irrigation is also installed to the red tee.
The 5th and final tee originally selected was 2 Becton winter tee. Since placing the tee blocks onto this area, it is not as uneven as other tees across the course. Therefore, a decision was made to change the last tee to 7 Needles white and yellow summer tee due to subsidence. This will not disrupt play due to a new mat already installed on this hole.
The target is to have all 5 tees levelled and turf laid before the end of January.
New mats are in play on 3 Becton, 7 & 9 Needles. Mats outstanding to be installed are 3 & 6 Stroller, unfortunately, due to weather conditions these are on hold until the following winter.
One set of steps are to be removed towards the rear of 3 Becton tee.
Two sets of new steps on 8 Becton and 6 Stroller will be installed during February.
Gorse has been trimmed back on 3 Stroller to open the view of the new bunkers.
9 Stroller path has been removed and turf laid. Other smaller paths such as 4 & 6 Needles will also be removed in future winter projects.
Welcome to the Autumn greenkeeping blog; since the last time of writing the weather has improved for turf health, however most would agree not for golf. The welcome sight of rain has increased grass sward recovery, turning the course green for the first time in two years. Applications of fertiliser, both granular and liquid, have been applied to all areas of the course. Weak fairways have seen additional feeds along with over-seeding to encourage growth while there is still enough warmth before the winter period. Greens recently underwent autumn renovations which have been a success and are now recovering tremendously, heading into a cold snap.
The winter construction programme on Stroller is now well under way. Stroller 1 consists of four new bunkers, removing the previous 3 bunkers, improving the hole both maintenance wise and aesthetically. This hole is now almost ready for new turf to be laid.
Stroller 3 and 6 are currently having earth works carried out, reducing the amount of bunker area and again drastically improving the holes. Work will shortly commence on 8 Stroller re-bunkering and mounding around the green to replace the high bunkers' faces which currently sit. These high faces are impossible to maintain as sand is either blown or washed down exposing stones and poor drainage.
The new path on 6 Becton has settled in nicely, once turf begins to arrive for the Stroller construction work the path on 6 Becton will be edged with new turf. A trial is also under way to source a new winter mat for 3 Becton, then other mats around the course. The new mat will need to be sturdy under foot as well as being able to place a tee anywhere within the mat. The final result should arrive soon.
Once the major section of the construction is complete, the next task of levelling certain tees will commence, weather permitting. An update will follow.
Finally, congratulations to Amy for succeeding in being selected to attend the greenkeeping BTME 3 day conference in Harrogate early next year. There are only two places, all expenses paid, up for grabs within the southern and southwest region of the country. Well done Amy!
Now summer is arriving, with the reduction in rainfall, some may say we never saw spring. We began the year incredibly dry, almost carrying on from the singe of last summer. Ideal for winter golf, however some much-needed moisture is something we could pray for.
There are still remnants of last summer showing across the course, the team has covered all areas with high nitrogen feeds, over-seeding and top dressing. Once the rain arrives there will be plenty of sward recovery.
Phase five winter construction on Becton is now in full play with some stunning bunkers, especially the 8th hole. Certainly, one that will be challenging in the easterly winds!
Greenkeeping is now in full swing with all machinery on the course. Four new additions are arriving imminently - two petrol utility vehicles and two greens mowers. This is part of our five-year rolling plan to upgrade machinery to ensure we run as efficiently as possible.
The team is working hard as the Club Championships arrive, focusing on presentation, greens speed and topping up bunkers with sand after strong winds earlier in the year removed a fair amount.
Finally, we are in the planning stage of renovating the staff quarters; this is an internal building within the green sheds that has come to the end of its life. The team members are looking forward to the change.
It was an exciting end to last year with arguably the most interesting course development project so far as it involved our Becton loop. Changes to the famous Harry Colt design had to be subtle and fit in with the rest of the course. Guided by the club's course architect, Howard Swan, all of the construction was done in house, which kept the team busy for 6 weeks. When asked if we had enjoyed the project it was unanimous - hard work but well worth the effort.
There have been some changes in the team over the last 6 months, with Kevin leaving us after just two years to further his career at Ferndown. We recruited quickly because of the winter schedule, finding Amy Thomas looking for a move from Farnham Golf Club. Amy is ambitious, well qualified and has proved a popular member of staff...she even made the boys brush up on their housekeeping in the sheds.
Over the last couple of years, the Board being very pro-active has allowed us to increase the team to 9 full time staff with 2 part time, incorporating the clubhouse gardening into the weekly work plans. This has enabled us to increase mowing and all presentation around the course. Away from basic greenkeeping the team has achieved diverse projects that are still ongoing. A clubhouse staff outside seating area has been built by Stroller 1st tee. The range buggy has its own garage alongside the maintenance sheds, purpose built by the team. Several other projects are in the pipeline, to be reported on in the next blog.