An Emergency Authorisation has been granted for the use of the Syngenta insecticide, Acelepryn, for the control of Chafer grubs and leatherjacket on golf course greens and tees, horse racing courses and airfields. The approval was applied for by STRI, on behalf of and with support from the amenity industry.
Chafer Grubs and leatherjackets cause damage to turf through extensive feeding on roots, which can be severe in localised patches. Furthermore, extreme damage can occur when badgers, birds and other foragers root through turf in search of the grubs.
The Emergency Authorisation permits Acelepryn use in situations where there is an acknowledged instance of economic damage and where the product has been recommended by a BASIS qualified advisor.
With the loss of available control options independent advisors, ADAS, has calculated the economic cost of Chafer Grubs alone at up to £85 million a year for golf courses in the UK, from lost income and damage repair. The report also highlighted that on the 40% of racecourses affected by the pest’s damage, lost income could amount to up to £605,000 per course.
‘”Since the withdrawal of effective insecticides, economic damage from chafer grubs and leatherjackets has been of major concern to many of us,” reported STRI Head of Research, Dr Ruth Mann. “Obtaining this Emergency Authorisation of Acelepryn enables us to manage the most damaging effects of these soil pests as part of an integrated turf management programme.”
Acelepryn UK Emergency Authorisation
The UK Emergency Authorisation for Acelepryn has been granted from 7 June to 30 September 2018, to cover the key Chafer Grub and leatherjacket treatment timing.
The Emergency Authorisation covers golf greens and tees, horse racing courses and airfields, specifically where there has been a history of pest damage or a recognised risk of damage. In all instances the use of Acelepryn must be recommended by a BASIS qualified agronomist.
The authorised label permits application at the rate of 0.6 litres per hectare, applied in 500-1000 l/ha water. Ideally Acelepryn should irrigated in after application. One application per year is permitted, with the latest time of treatment being 30 September.
Turf managers or owners who believe they have suffered economically damaging effects of Chafer grubs and leatherjackets are advised to contact their BASIS agronomist or ICL Area Manager in the first instance.
Targetting pests
Understanding the life-cycles of different target soil pests is seen as crucial in timing management options effectively, to optimise performance of Acelepryn and to minimise its use.
Chafer Grub
Three key species of Chafer affect turf in the UK – the Garden Chafer; Summer Chafer and Cockchafer (Maybug). In some areas the Welsh Chafer can be a localised problem. Whilst the adult insects differ, all are characterised by the similar white grubs that feed on turf roots and can cause extensive damage.
However, there are differences in the life-cycle of each species that has an impact on their turf effects. The Garden Chafer, for example, goes through its entire life-cycle in one season - from egg laying, through all larval stages (instars) and emergence of adults; whilst the Cockchafer larvae instars live and feed in the soil for three years to go through the same process. The adult egg laying and hatching period is also different for each specific species.
As Chafer grubs develop through successive moults, they get progressively larger which can cause greater damage to turf – as well as being far more difficult to control. Acelepryn is active on the 1st and 2nd instar stages only. Both nematodes and previous controls have always been targeted at early instar stages.
Chafers are mostly associated with light, open, sandy soils – which can make them especially prevalent on golf green constructions.
Leatherjackets
The annual life cycle of the Crane Fly (Daddy Long Legs) sees eggs, laid on bare soil in mid to late summer. Eggs quickly hatch to emerge and go through several leatherjacket larvae growth stages (instars) in the soil as they feed on organic matter and develop.
The leatherjackets are grey/brown to green/grey in colour, legless maggots with no distinct head capsule. The first stage larvae are around 0.3 cm 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.
In the UK, the peak adult Crane Fly activity would typically be seen in August to early September with Tipula paludosa and Tipula oleracea species emerging – although T. oleracea also emerge in the spring and can travel long distances over the summer months. Each adult lays up to 400 eggs, typically in small batches of five to 10 eggs across an area.
In golf turf, a threshold of 16 leatherjackets m2 has been proposed for insecticidal application. Reports have identified more than 1000 leatherjackets m2 on heavily infested turf. Turfgrass that is already under stress or shallow rooted will be more severely damaged by leatherjackets, particularly in winter when turf growth or recovery is slow.
Conditions have been particularly favourable for leatherjackets in recent years; the larvae thrive in wetter soil conditions over the summer, and then dry, settled weather when the adult flies emerge. The pest is most prevalent in wetter regions, but can be especially problematic in well irrigated sports turf surfaces.
UK Guidelines for Acelepryn use
Stewardship guidelines highlight that Acelepryn will only be supplied on BASIS recommendation, from approved agronomists that have completed training in its use.
The Guidelines indicate Acelepryn application only where pest activity has previously been identified as economically damaging, or where economic damage will occur as identified by the presence of significant numbers of egg laying adults.
Furthermore, Acelepryn application should be targeted at the thatch layer, using a water volume of at least 500 l/ha and appropriate larger orifice nozzles to aid penetration to the thatch and to avoid drift onto non-target areas. Treatments should be watered in with 3- 6 mm of irrigation as soon as possible after application.
The optimum time of application is before the start of egg-laying since the product needs time to move through the thatch layer to the zone where the grubs and larvae reside.
Turf managers or owners who believe they have suffered economically damaging effects of Chafer grubs and leatherjackets are advised to contact their BASIS agronomist or ICL Area Manager in the first instance.
Click here to download a copy of the Acelepryn Emergency Approval product label
Click here to download the Acelepryn SDS
Click here to download the Acelepryn Question & Answer Sheet