The First Record of Tortoise Beetle Damage to Sugar Beet in the UK: Is Global Warming Responsible?

Abstract

The authors thought they had experienced everything that the sugar beet crop could throw at them from a pest point of view after almost 40 years of working with the sugar beet industry. It was therefore very exciting to be confronted with a highly unusual pest this summer, so unusual that its presence in high numbers causing significant damage to a sugar beet crop in Norfolk in August 2021, is the first record of such damage in the UK. The pest was the exotic tortoise beetle, Cassida nebulosa, which the sugar beet bible, Pests, Diseases and Disorders of Sugar Beet, published by the International Institute de la Recherches Betteraves (IIRB), describes as rare, and never important in northern Europe. Indeed, this species has never, in our memory, been recorded before as a pest in sugar beet in the UK, only a very rare presence. Dewar and Cooke (2006) stated in their review of pest problems in sugar beet the UK, that crop damage by tortoise beetles never occurs in western Europe, but can be severe in warmer Mediterranean regions and in Russia.