Adriaens, TimResearch Institute for Nature and Forest (INBO), Brussels, Belgium
Brown, Peter M. J.Animal & Environment Research Group, Department of Life Sciences, Anglia Ruskin University, Cambridge, UK
Katsanis, AngelosCABI, Delémont, Switzerland - Department of Ecology and Evolutionary Biology, University of California – Irvine, USA
Martin, Gilles SanDépartement Sciences du Vivant, Centre Wallon de Recherches Agronomiques, Unité Protection des Plantes et Ecotoxicologie, Gembloux, Belgium
Branquart, EtienneInvasive Species, UnitDépartement de l’Etude du Milieu Naturel et Agricole (DEMNA), Gembloux, Belgium
Maes, DirkResearch Institute for Nature and Forest (INBO), Brussels, Belgium
Roy, Helen E.NERC Centre for Ecology & Hydrology, Crowmarsh, Gifford, UK
Hautier, LouisDépartement Sciences du Vivant, Centre Wallon de Recherches Agronomiques, Unité Protection des Plantes et Ecotoxicologie, Gembloux, Belgium
English
Invasive alien predators are a serious threat to biodiversity worldwide. However, there is no generic method for assessing which local species are most at risk following the invasion of a new predator. The harlequin ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), is an alien in Europe and many other parts of the world where it affects other species of ladybirds through competition for food and intra-guild predation (IGP). Here, we describe a method developed to assess which European ladybird species are most at risk following the invasion of H. axyridis. The three components of the risk assessment are: the likelihood that the assessed native species encounters H. axyridis in the field, the hazard of competition for food, and the IGP hazard. Thirty native European ladybird species were assessed through data obtained from field observations, laboratory experiments and literature reviews. The species that are considered most at risk are found on deciduous trees, have immature stages which are highly vulnerable to IGP by H. axyridis, and are primarily aphidophagous. These species should be the focus of specific studies and possibly conservation actions. The risk assessment method proposed here could be applied to other alien predators which are considered a threat to native species through competition and predation.