Before starting a word on IPDM (Integrated Pest and Disease Management) points to bear in mind:

Priority of control in IPDM is as follows and in relation to chafer grub control:

  1. Cultural – reduce thatch on fairways, tees, greens and other areas. Reduce nearby harbouring vegetation.
  2. Biological – attempt use of nematode control of chafer grubs using Buy Nemasys-G Chafer Grub Killer - Nematodes Direct, SportNem H, Chafer Grub Killer Nematodes - Heterorhabditis bacteriophora - Dragonflietc, and also use traps e.g. Chafer Beetle Trap - Nematodes Direct Chafer Grub - Biological Pest Control - Other ( to capture adults during breeding season. This may be the fastest route to control at present.
  3. Physical – intensive microtining of greens with 5-6mm solid tines may physically injury a proportion of the grubs and lead to some deaths.
  4. Chemical – the last choice always – and when infestation becomes bad the only choice and in the case of Chafer grubs Acelerpryn is the only product available for use on strict controls.

About Chafers

  • Chafers – are larvae of beetles that feed on roots causing stress to turf and cause loss of surface stability, but the main problem is often predators attacking the turf to reach the chafer grubs.
  • They prefer more thatch and fibre/organic matter as are local tree and shrub proximity – so organic matter control is important as is site vegetation management.
  • 4 species of chafer grub – only impacted in 1st and 2nd instar stage of grub.
  • Most reports of greenkeeping problems in May and June.
  • Garden Chafer – green head – 1 year life cycle.
  • Summer Chafer – brown furry head – 2 year life cycle – must treat them in first year of grub life cycle likely impact 50% kill with acelerpryn of 1st year juveniles therefore two years treatment needed.
  • Cock Chafer – large black shiny head, largest – 3 year life cycle likely only 30% kill of first year juveniles by acelerpryn so three years treatment necessary to limit numbers.
  • Welsh Chafer and Brown Chafer are among other species – widespread distribution.
  • Soil Pest Identification | Syngenta Turf & Landscape

The following notes are provided for guidance only and to give a brief overview of the use of Acerlerpryn and to discuss IPDM measures that should also be considered:

  • Licence is only 120 days – emergency use only
  • Approved rate 0.6L/ha bottle size is 0.6L
  • Bottle will be with American label with UK instructions provided.
  • Mode of action: Acelerpryn paralyses insect and it decomposes in situ. Takes time to work into soil and 3-4 weeks to reach the chafer grubs at maximal levels.  90% control achieved.
  • Timing is therefore to apply before damage occurs. Apply during / just prior to decent rain (especially on fairways).
  • Stays in soil for up to two months so good residual presence.
  • See Greencast website for further identification assistance – great pictures (details below)
  • Supply available until 4.8.2021
  • Use by 31.8.2021
  • Use on golf tees and greens and fairways, horse gallops and race courses, airfields.
  • Only one application per year whether for leatherjackets or chafer grubs!
  • Can only use on 10% of golf course area – data will need to be specified of treatment areas
  • Maximum of 10% of fairway area in patches – data will need to be specified of treatment areas
  • Cannot be used on grazed areas
  • Stewardship information will be required to be submitted to ICL/supplier which will be supplied to the HSE in an Excel spreadsheet.
  • Sales / Recommendations only by BASIS qualified sales and agronomists
  • Separate stewardship form will be required for leatherjackets when approval comes through for this but currently only for Chafer grubs.
  • When information has been submitted ICL will approve the use and sale with the conditions supplied alongside a reference number to be put on the dealer’s order form for checking with supplier.
  • Note: Crane fly larvae – leatherjackets – approval not yet given for use on leather jackets. Don’t succumb to temptation to use for leatherjackets.
  • The emphasis on correct and proper use is therefore significant and considerable so it is essential to follow the process and legislation to the letter.


  • Apply preventatively at the right time when rain is imminent.
  • Use Pest Tracker to help build a picture of likely problems.
  • Mow before application and after application return clippings as much as possible.
  • Application at 0.6L/ha apply minimum 600L of water, ideally 1000L. Use Syngenta XC or suitable air induction nozzle, minimum of 08 nozzles. Pressure as low as possible ideally 2-3 bar, and no more than 4 Bar.
  • Need minimal drift therefore larger droplets and lots of water volume. Water volume is mostly impacted by nozzle ouput – choose the right nozzle (see nozzle charts) – use white nozzle of the right size) speed 5-6kph (3.1-3.7mph) and 2-3 bar pressure should generate water volumes required.  Use Greencast Turf App to help calibration. Don’t use red nozzle or purple nozzle.
  • Need 3-6 mm or rain minimum after application or use irrigation.
  • Wetting agents use doesn’t show any benefit unless very hydrophobic. Ideally sort this problem before use but Qualibra is tank mix compatible.
  • Return clippings after use.

Further information is available on Greencast regarding Acelerpryn and in this video link

Acelepryn Chafer Grub Emergency Authorisation May - August 2021 | Training on Vimeo

Acelepryn Emergency Authorisation for chafer grubs | Syngenta Turf & Landscape

GreenCast Tools | Syngenta Turf & Landscape

Turf Pest Tracker | Syngenta Turf & Landscape

Remember that product will only be available with a fully completed stewardship form!

Sports Turf Consulting Ltd is an independent agronomy support business and is not affiliated with ICL or other suppliers listed here.  The information offered here is for guidance and support and direct sales relationships with suppliers is required to source Acelerpryn and complete the stewardship clearance.  Many distributors will be offering Acelerpryn as part of their product portfolio – however, to access product it must be recommended by a BASIS certified technical representative or Agronomist.

Sports Turf Consulting Ltd Agronomy Support – we are happy to support clients with applications to purchase Acelerpryn by being a witness to the presence and will provide my BASIS number on request if needed provided I have seen Chafer Grubs on site or evidence of their presence is submitted which is verifiable (e.g. video showing location and excavation of grubs without editing breaks).

We are particularly keen to ensure clients understand their responsibility under IPDM to generate systems to limit pests using the 4 set process outlined at the start.  Whilst Acelerpryn is a welcome addition to our armoury it is not a quick fix taking probably weeks to gain control to a good level.  Faced with a serious immediate threat our opinion is that fastest results may be achieved with Chafer parasitic nematode control if used correctly.  Apply these in low light in the evening to wet surfaces in line with recommendations and water in or apply before rainfall.

Noel MacKenzie B.Sc.(Hons), BASIS, RIPTA, MRSB, MCIHORT.  7th May 2021