Cannibalism in invasive, native and biocontrol populations of the harlequin ladybird

Tayeh, Ashraf; Estoup, Arnaud; Lombaert, Eric; Guillemaud, Thomas; Kirichenko, Natalia; Lawson-Handley, Lori; De Clercq, Patrick; Facon, Benoît

Abstract

Background
Cannibalism is widespread in both vertebrates and invertebrates but its extent is variable between and within species. Cannibalism depends on population density and nutritional conditions, and could be beneficial during colonisation of new environments. Empirical studies are needed to determine whether this trait might facilitate invasion of a new area in natural systems. We investigated whether the propensity for cannibalism in H. axyridis differs both between native and invasive populations and between invasive populations from the core and from the front of the invasive area in Western Europe. We also compared the propensity for cannibalism of these natural populations with that of laboratory-reared biocontrol populations. We measured the cannibalism rates of eggs by first instar larvae and adult females at two different individual densities of ladybirds from three types of population (invasive, native and biocontrol), in laboratory-controlled conditions.

Results
Cannibalism was significantly greater in larvae from invasive populations compared to native or biocontrol populations, but there was no difference in cannibalism rates between populations from the core or front of the invaded range. Cannibalism was significantly lower in larvae from biocontrol populations compared to wild (invasive and native) populations. No differences in cannibalism rates of adult females were found between any populations. While high population density significantly increased cannibalism in both larvae and adults, the norm of reaction of cannibalism to individual density did not change significantly during the invasion and/or laboratory rearing processes.

Conclusion
This study is the first to provide evidence for a higher propensity for cannibalism in invasive populations compared to native ones. Our experiments also shed light on the difference in cannibalism evolution with respect to life stages. However, we are still at an early stage in understanding the underlying mechanisms and several different research perspectives are needed to determine whether the higher propensity for cannibalism is a general feature of the invasion process.

Citation

Tayeh, A., Estoup, A., Lombaert, E., Guillemaud, T., Kirichenko, N., Lawson-Handley, L., De Clercq, P., & Facon, B. (2014). Cannibalism in invasive, native and biocontrol populations of the harlequin ladybird. BMC evolutionary biology, 14(1), Article 15. https://doi.org/10.1186/1471-2148-14-15

• Journal Article Type: Article
• Acceptance Date: Jan 7, 2014
• Publication Date: Feb 5, 2014
• Deposit Date: Aug 6, 2018
• Publicly Available Date: Aug 14, 2018
• Journal: BMC Evolutionary Biology
• Print ISSN: 1471-2148
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Issue: 1
• Article Number: 15
• DOI: https://doi.org/10.1186/1471-2148-14-15
• Keywords: Harmonia axyridis; Cannibalism; Evolution; Invasive; Native and biocontrol populations
• Public URL: https://hull-repository.worktribe.com/output/967822
• Publisher URL: https://bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-14-15
• Contract Date: Aug 6, 2018