How Sempliance works: a new tool for caterpillar control in UK ornamentals
Fast-acting, long-lasting, and built for IPM
With Sempliance now available to UK growers, we wanted to give a clear picture of what this new insecticide actually does, how it works, and why it's a welcome addition to the toolkit.
What is Sempliance?
Sempliance is an insecticide from Syngenta containing chlorantraniliprole, an active ingredient from the anthranilic diamide class of chemistry (IRAC Group 28). It is approved for use on ornamental plants grown in pots greater than 10cm in diameter, targeting a broad range of caterpillar species - including those that have become increasingly problematic on UK nurseries in recent years.
A unique mode of action
What sets Sempliance apart from many conventional insecticides is how it works. Chlorantraniliprole targets the ryanodine receptors in insect muscle cells, disrupting the regulation of calcium ions and causing uncontrolled muscle activation. In practice, this means that caterpillars feeding on treated plant material quickly become paralysed - they stop feeding almost immediately, before dying shortly after. This is significant for growers because the feeding damage stops fast and you don't have to wait for the pest to complete its life cycle or for populations to decrease over time. The crop is protected from the moment the product takes effect.
Long-lasting residual activity
One of the most practically useful features of Sempliance is its residual activity. Unlike contact-only products that break down quickly and require frequent reapplication, Sempliance maintains effective activity for an extended period after application. For growers managing large volumes of stock, this means fewer spray rounds, less disruption, and better overall efficiency in the crop protection programme.
Ovi-larvicidal activity: breaking the cycle
Sempliance also has ovi-larvicidal activity - meaning it is effective against both eggs and young larvae. This is particularly valuable when pest pressure is building or when new generations are beginning to establish. By disrupting the pest life cycle at multiple stages, Sempliance helps prevent infestations from taking hold in the first place, rather than simply reacting once damage is already visible.
Designed for IPM programmes
With resistance management a priority for the whole industry, the fact that Sempliance offers a different mode of action to many existing caterpillar products makes it a genuinely useful rotational partner. Its selectivity profile - effective against caterpillars without the broad-spectrum impact of some older chemistries - also makes it a practical fit within programmes that include biological control agents. Strong performance in IPM trials supports its use as part of a structured, responsible approach to pest management and Sempliance is not just a standalone solution, it is a very capable one.
--- Always read the label before use. Sempliance is approved for use on ornamental plants grown in pots greater than 10cm in diameter in Great Britain and Northern Ireland.