Emergency authorisation to use Coragen on 2025 sugar beet crop granted 

With some areas already seeing beet moth activity, British Sugar and NFU Sugar, supported by early findings from the BBRO and European data supplied by FMC, submitted an emergency authorisation request for the option of Coragen application for effective control of the pest in this year’s crop.

This emergency authorisation for use started on 4th July 2025 and will end on 30th September 2025.

NFU Sugar and British Sugar are reminding growers that they must record:

· the date and locations of treatment,

· the number of treated hectares,

· percentage of crop affected by beet moth, and

· fate of the sugar beet tops.

Beet tops must not be fed/grazed by any livestock.

British Sugar will contact all growers after the emergency authorisation expiry date to collect information on the use of Coragen in the 2025 crop.

Concerns about beet moth

BBRO confirmed that there are increasing concerns regarding beet moth this year, with the hot, dry weather being conducive for its reproduction and spread.

Unlike other species, the beet moth caterpillars tend to mine into the stems and crown, causing damage to the hearts of the beets. In some areas, the beet moth appears to have been flying since late April and could potentially carry on until October if the weather remains conducive for their flight.

This adds to the pressure of determining the best time to apply sprays. Potentially the best timing is at egg hatch, with the threshold for treatment in several other European countries being when 10% of plants show damage to the heart leaves, BBRO experts said.

They added: “We are continuing pheromone monitoring and have an ongoing project to better understand the beet moth life cycle at Warwick University, as the exact time of egg-laying and hatching is not currently known.

“Drought-stressed canopies will be at higher risk for beet moth infestation as the crown will be more exposed for moths to lay their eggs and caterpillars to burrow into.”

BBRO confirmed that Coragen can be applied up to the 30th September 2025 and has a harvest interval of 21 days.

It is important to note that the Coragen label states it must not be applied to any crop suffering from stress, for example, as a result of drought or disease attack. Some pyrethroids, such as those containing the active cypermethrin, are also available with label approval for caterpillars, however, these actives will have wider impacts on beneficial insects.

To aid actives reaching the target caterpillars, high water volumes are required to penetrate the canopy, BBRO experts concluded.

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