London, England: A new Emergency Authorisation (EA) for the use of the Syngenta insecticide, Acelepryn, has been approved to target leatherjackets for the 2021 season.

The EA permits use of Acelepryn on affected greens, tees and fairways, along with horse race courses, training gallops and airfields. This season in the United Kingdom and Ireland, the treatment period for leatherjackets is permitted until November 29.

“The extended application period does allow a longer window of treatment to target larvae activity from later hatching crane fly at the most appropriate timing,” said ICL Technical Manager Henry Bechelet, who applied for the Emergency Authorisation on behalf of the industry.

New Syngenta research has been investigating the optimum application timing in challenging situations, particularly where larvae activity may be occurring later in the season. It has also looked at the role of integrated measures to mitigate against leatherjacket damage, including adapting aeration and renovation strategies. 

Leatherjackets cause damage to turf through feeding on roots and leaves – typically resulting in pock-marked and uneven surfaces, which can be severe in localised patches, Bechelet pointed out.

Racecourses and horse gallops are especially prone to surface instability where root damage is caused by soil pests.

Furthermore, extensive damage can occur in all turf surfaces when badgers, birds and other foragers root through turf in search of leatherjackets. Flocks of birds attracted to feed on larvae are of particular concern on airfields.

Leatherjackets are the larvae of crane fly (daddy longs legs). Adults typically emerge from July in the United Kingdom, although hatching may be extended into the autumn depending on weather conditions.

“The extension of use to the end of November could prove extremely useful to target later emerging leatherjackets,” he added.

The new leatherjacket EA supplements the chafer grub specific authorisation announced earlier this year.

The best results have been achieved with applications when young leatherjackets, at the first and second instar stages, are actively feeding near the soil surface, according to Glenn Kirby, Technical Manager at Syngenta, an Executive Member of the Asian Golf Industry Federation.

“It’s important to apply at higher water volumes, using the white O8 XC Nozzle to target the spray through to the soil surface,” advised Kirby. “Irrigation where possible will help to move the spray into the target zone.”     

The authorised label permits application at the rate of 0.6 litres per hectare, applied in 500-1000 l/ha water. Only one application per year is permitted on any given area.

Greenkeepers and turf managers are urged to report sightings of crane fly activity through the on-line Pest Tracker. The aim is to build a picture of pest activity across the United Kingdom and Ireland, to anticipate issues and aid application timing.