Aphid Outbreak Leaves 30 Million Lettuces Unharvested As Losses Exceed £10 Million

An estimated 30 million lettuce heads went unharvested in September as severe aphid infestations caused losses exceeding £10 million, according to the British Leafy Salads Association (BLSA).

Some businesses were left with up to 85% of production unmarketable, the association told Farmers Guardian, following a second consecutive season of record infestations.

Growers reported between 300,000 and 400,000 currant-lettuce aphids (*Nasonovia ribisnigri*) per hectare during August and September. Commercially significant volumes of lettuce and baby leaf were affected.

Warm, dry summer conditions favoured the pest across England’s main growing regions, including East Anglia, the Midlands, the North West, Central South and South East. Populations peaked in late June and again in August and September.

The losses represent a substantial blow, although the BLSA has stressed the importance of distinguishing the late-season outbreak from production across the whole year. Speaking to Fruitnet in September, association spokesperson Dieter Lloyd said UK growers produce more than half a billion lettuce heads during a season running from May to September.

He emphasised that British lettuce had been available throughout the summer, with the most severe pressure concentrated towards the season’s end. Crisphead, romaine and iceberg lettuces were expected to be among the worst affected. Lloyd said developing solutions would require sustained collaboration between the industry’s different stakeholders.

The BLSA is coordinating work with growers, breeders, researchers and policymakers. Growers have invested £200,000 across 2025 and 2026, alongside land, time and resources, in monitoring, research and field trials.

Priorities include improving crop protection practices, testing control methods and developing more resilient crops. The association is also engaging regulators and policymakers to secure coordinated support for UK leafy salad production.