Invasion success of a widespread invasive predator may be explained by a high predatory efficacy but may be influenced by pathogen infection

Author
Fincham William N. W.
Dunn Alison M.
Brown Lee E.
Hesketh Helen
Roy Helen E.
Abstract
Invasive alien species (IAS) can drive community change through ecological interactions. Parasites and pathogens can play an important role in community function including mitigating or enhancing IAS impacts. Despite this, the degree to which pathogen pressure influences IAS impacts remains poorly understood. We quantified the predatory behaviour of the highly invasive alien harlequin ladybird (Harmonia axyridis) and two UK native species, the 7-spot (Coccinella septempunctata) and 2-spot (Adalia bipunctata) ladybirds, using comparative functional response experiments. We investigated the impacts of pathogen infection on the predatory ability of the ladybirds by exposing individuals to Beauveria bassiana, a widespread entomopathogen. Invasive H. axyridis was a more efficient predator than both the native A. bipunctata and C. septempunctata, often having higher attack and/or lower prey handling time coefficients, whereas native A. bipunctata were the least efficient predators. These differences were found in both adult and larval life-stages. Beauveria bassiana infection significantly altered the predatory efficiency of adult and larval ladybird predators. The effects of pathogenic infection differed between species and life-stage but in many cases infection resulted in a reduced predatory ability. We suggest that the interactions between IAS and pathogens are integral to determining invasion success and impact.
Year of Publication
2019
Journal
Biological Invasions
Volume
21
Issue
12
Number of Pages
3545-3560,
Date Published
2019/12/01
ISBN Number
1573-1464
URL
DOI
10.1007/s10530-019-02067-w
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