Harlequin ladybird invasion could endanger 1000 native UK species

Harlequin succinea - Credit the late Professor Mike Majerus of Cambridge University.

Unravelling the story of an alien invader
June 2009. Scientists presenting at the Royal Society Summer Science Exhibition, which opened on 30th June will say that the harlequin ladybird is likely to threaten over 1000 native species in Britain.

Spread across the country in just 4 yearsThe harlequin has spread from Essex to Orkney in only four years and is now one of the fastest spreading non-native insects in Europe and the most invasive ladybird on Earth. Scientists from across the UK have been working to monitor its spread and impact. They are also seeking inventive methods of control, some of which will be presented at the Exhibition.

Harlequin caused severe declines in the USA

Project leader, Dr Helen Roy from the Centre for Ecology & Hydrology said: "We believe that the negative impacts of the harlequin on Britain will be far reaching and disruptive, with the potential to affect over 1000 of our native species. In the United States, where the harlequin arrived over 20 years ago, it has been associated with severe declines in native species."

Harlequin survey

The researchers' first step has been to understand how the harlequin has spread. The public has played a key role in monitoring the invasion through the Harlequin Ladybird Survey (www.harlequin-survey.org), which was launched in 2005, and has now received over 30,000 online records.

Invasive alien species - Major threat to biodiversity

"Invasive alien species are one of the greatest threats to global biodiversity," says co-investigator Dr Remy Ware from the University of Cambridge. "Using data from the Harlequin and UK Ladybird Surveys, we have a unique opportunity to study the early establishment, spread and adaptation of an invasive species."

Natural, native enemies

The research team are now exploring how the few native enemies that do exist could be used to control the harlequin invasion. One of the most promising ideas is using a sexually transmitted mite, which makes some ladybirds infertile. If the transmission of these mites could be encouraged, the harlequin population could become greatly reduced. Other possible control options are through fungal disease, male-killing bacteria, a parasitic wasp and two species of parasitic fly.

The scientists will be on hand at the exhibition, which runs from 30 June to 4 July, to talk visitors through their research. On the exhibition stand, visitors can learn how to distinguish harlequins from native species, get up close and personal with harlequins under the microscope, and find out how scientists are trying to control the invasion.

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