Decline in native ladybirds in response to the arrival of the harlequin ladybird Harmonia axyridis

Changes in UK ladybird species assemblages were assessed during the invasion phase of the alien harlequin ladybird. Harlequins increased from 0.1% (year 1) to 40% (year 3) of total ladybirds sampled, whilst native aphidophagous ladybirds declined from 84% to 41%. Competition and intraguild predation particularly impacted the 2-spot ladybird