Modeling Harmonia axyridis interactions within the aphidophagous guild

The rapid spread of Harmonia axyridis across the British Isles is predicted to impact native coccinellids through direct competition and intra-guild predation. Additionally, the population dynamics and seasonal overlap of coccinellids with their aphid prey is likely to be affected by climate change. The combined effects of these two factors could alter relationships within the aphidophagous guild. Here we describe methods to quantify the impact of H. axyridis on temporally and spatially overlapping and non-overlapping native coccinellids, quantifying the relative role of top-down, bottom-up and abiotic factors in driving native coccinellid dynamics. Specifically, changes in coccinellid community composition and the functional responses of coccinellids to the abundance of different prey species will be investigated, and long-term datasets will be used to analyse coccinellid and aphid temporal-spatial dynamics in relation to climate, using climate envelope models to assess the role of climate change on coccinellid-prey interactions. The ultimate aim is to quantify responses of native coccinellids to H. axyridis, accounting for species’ differing specialisations.