For the publicLadybird, ladybird: unravelling the story of an alien invader

The alien harlequin ladybird, Harmonia axyridis
The alien harlequin ladybird
Harmonia axyridis

This project was presented at the 2009 Royal Society Summer Science Exhibition.

Links: Poster | Comic | Video | Photographs | Royal Society page
Scientists: Judith Pell, Jason Baverstock and Trish Wells

Indigenous natural enemies deliver an important pest management service within agro-ecosystems. The structure and diversity of the natural enemy community, and its resulting impact on pest population densities, are influenced by interactions between the natural enemies themselves, the pests and the environment. We predict that, in the long term, maintaining diversity in natural enemy guilds ensures stable pest suppression under variable environmental conditions. The alien harlequin ladybird, Harmonia axyridis, a polyphagous predator favouring aphids, invaded the UK in 2004.

It is already known to be a significant intra-guild predator of other ladybirds with the potential to reduce the diversity and abundance of our native natural enemy communities and disrupt the ecosystem services they provide. The objective of this project is to quantify the strength of inter-enemy interactions in the presence and absence of H. axyridis at increasing spatial scales and habitat complexity from Petri dish studies to mesocosms and field observations. The potential for natural enemy co-existence in the presence of H. axyridis and aphid suppression by single and multi-species natural enemy assemblages will be evaluated.

This project is a Ph.D. studentship sponsored by the Biotechnology and Biological Sciences Research Council.
Click here for more information


Intraguild predation by the Harlequin Ladybird by Patricia M. Wells, Jason Baverstock, Michael E. N. Majerus, Helen E. Roy and Judith K. Pell. This is a 16MB Adobe Acrobat PDF file.


Ladybird, ladybird: unravelling the story of an alien invader. This is a 13MB Adobe Acrobat PDF file.

Click here to download the comic



Larva in defensive posture
Larva in defensive posture

Pupal stage

Eating an aphid
Eating an aphid