Sempliance puts Box Tree Moth on the back foot
Expert Centre blog
Sempliance puts Box Tree Moth on the back foot

 

Box Tree Moth (Cydalima perspectalis) has become one of the most damaging pests in the UK ornamentals sector. Since establishing in Britain, it has spread aggressively, with Buxus plantings in nurseries, garden centres, and amenity landscapes all at risk. The pest is now firmly embedded in the UK pest calendar, capable of producing multiple generations per season and causing severe, often irreversible defoliation. With this in mind, Syngenta has proactively been implementing trials across Europe, using Sempliance (chlorantraniliprole), to mitigate these ever increasing challenges. 

 

What the trials show

Replicated field trials conducted on Buxus sempervirens in the Netherlands and Italy across 2022 and 2023 consistently demonstrated strong control of Cydalima perspectalis with Sempliance.

 

Netherlands 2022  

Crop: Buxus sempervirens, Target: Cydalima perspectalis, 4 replications, 1,000 l/ha water volume, infestation: 10–20 eggs per plot, 6th May

All Sempliance treatments delivered good control of Box Tree Moth larvae, with a two-application programme giving the best overall result. Adjuvants had limited additional effect, reflecting the high baseline efficacy of Sempliance alone. Used in alternation with Bacillus thuringiensis subsp. aizawai (BT), Sempliance continued to perform well, confirming its fit within IPM alternation programmes.

 

Netherlands 2023

Crop: Buxus sempervirens, 4 replications, 1,000 l/ha, infestation: 28th April

In the 2023 trial, all Sempliance treatments again achieved strong control of Box Tree Moth, with results at 20 days after application (20 DAA) confirming consistent performance across all programmes. Where Sempliance was used in alternation with BT, good control was maintained throughout, with both BT and azadirachtin identified as sound alternation partners within an IPM programme. Additional points to confirm are that feeding damage stops within a maximum of three days following a single application, with residual activity maintained beyond two weeks and protection still evident at four weeks post-application.

 

Italy - Pistoia, Tuscany 

Crop: Buxus microphylla 'Faulkner', Target: Cydalima perspectalis, GEP trial, CRO: Sagea, open field, applications window: 12th June – 24th July

Trials conducted in Pistoia, Tuscany, showed that a single Sempliance application provided effective control of the second generation of Box Tree Moth and measurably reduced pressure from the third. A two-application programme delivered superior, sustained protection across both generations, with Sempliance programmes - both conventional and IPM - outperforming the standard reference programme in all comparisons.

 

Expert view

"Box Tree Moth is now firmly established as one of the most serious pest threats we see in European ornamentals, and the UK is no exception," says Marcel Hubers, Ornamentals Technical Manager for Europe at Syngenta. "The trial results across the Netherlands and Italy are very consistent - Sempliance gives strong, reliable control across generations, and the residual activity means growers have real protection in between spray timings. The fit with IPM programmes using BT as an alternation partner is also important for UK growers who are working within integrated programmes. This is a product backed by solid data, and we are confident in what it will deliver."

Sempliance puts Box Tree Moth on the back foot

 

Application guidance

  • Apply at first signs of egg lay or early larval emergence - targeting L1/L2 larval stages gives the best results
  1. Use a water volume of 1,000 litres per hectare to achieve thorough canopy coverage on Buxus
  2. A two-application programme targeting separate generations gives the strongest season-long control
  3. In IPM programmes, alternate with **BT (Bacillus thuringiensis subsp. aizawai) or azadirachtin** between Sempliance applications
  4. Rotate with products from a different IRAC group across successive generations to support Insecticide Resistance Management (IRM)
  5. Adjuvants are not required for efficacy against Box Tree Moth, though they can improve uptake in dense canopies

 

A well-timed addition for UK growers

Box Tree Moth is not going away. As the pest continues to extend its range and growers face repeated pressure season after season, the need for a reliable, long-lasting insecticide option has never been greater. Sempliance - the only diamide-based product approved for outdoor ornamentals in the UK - brings a well-proven European performance record to British growers for the first time. With consistent trial results across multiple countries and seasons, strong IPM compatibility, and the flexibility of a long residual activity, it is a timely and well-evidenced addition to the UK ornamentals toolbox.

 

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