Ladybird, Ladybird: unravelling the story of an alien invader

Published: 1 July 2009 at 14:22

Scientists join forces to protect over 1000 ladybird species which are at risk

Scientists from Anglia Ruskin University, University of Cambridge and Centre for Ecology & Hydrology (CEH) have been collaborating to monitor the spread and impact of the invasive harlequin ladybird, Harmonia axyridis, since its arrival in Britain in 2004.  Now they have the opportunity to explain their work at the prestigious Royal Society Summer Exhibition – the science show of the year – taking place from Tuesday 30 June to Saturday 4 July 2009 (see for details).

Using stringent and imaginative experiments, the research team, together with further collaborators at Rothamsted Research and Hull University, are exploring their prediction that over 1000 species in Britain are at risk from the harlequin, and how it might be controlled.

“Invasive alien species are one of the greatest threats to global biodiversity”

says 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.”

The harlequin is a voracious predator and while it mainly feeds on pest insects such as aphids (greenfly), it is also known to feed on other insects, including various ladybird species. 

There is therefore great concern over negative impacts on native ladybirds. Anglia Ruskin has had a major role in the project since the start, with Dr Helen Roy (now Centre for Ecology and Hydrology) and the late Professor Mike Majerus (University of Cambridge) founding the Harlequin Ladybird Survey.  

Now Peter Brown, Dr Alison Thomas and Styliana Philippou, all from the Department of Life Sciences at Anglia Ruskin, and Dr Ware, are working on a project to determine and quantify predation levels on native ladybirds in the wild, using genetic techniques. The Polymerase Chain Reaction (PCR) is a method for making many copies of a specific DNA sequence and allows the scientists to detect and identify what has been eaten by a harlequin ladybird, by analysing prey DNA present in the harlequin’s gut contents.

As Alison Thomas, lead scientist on this project, explains:

"This technique has great potential to identify what the harlequin ladybird is eating in the field."

Peter Brown, who is completing his PhD on the spread of the harlequin and its effects on native ladybirds, says:

“The harlequin is one of the fastest spreading insects in Europe and seems to be having a seriously negative effect on native ladybirds.  His data shows that generalist species such as the 2-spot, 7-spot and 14-spot ladybirds are faring worst.”

In the words of exhibit organiser Helen Roy:

“Anglia Ruskin University is contributing hugely to the success of this exhibition thanks to the enthusiasm of Pete Brown and Alison Thomas. They have driven this project since the outset and will continue to dedicate their time to it until our native ladybirds are finally protected from this aggressive invader.”

The exhibition is taking place at the Royal Society, 6-9 Carlton House Terrace, London, SW1Y 5AG. On the exhibition stand, you can learn how to distinguish harlequins from our native species, see harlequins behaving badly, get up close to them under the microscope, find out how scientists are trying to control the invasion and how you can help by catching the invasive bug.

For further information see and