In early areas (Cornwall and parts of Kent, Suffolk and Norfolk) where the pest is already active, growers should have already begun treatment.
The next areas predicted to become active (ie when 10% of insects have emerged or laid eggs) are Nottingham and Lancashire (20th April) followed, about a week later, by York and Scotland, according to data collected by Plantsystems Ltd.
The start of egg laying is predicted to be between 26th of April and 7th of May depending on locality.
This information was published in the ADAS Veg Notes. For further information, go to the ADAS website.