In the shadow of the condor: invasive Harmonia axyridis found at very high altitude in the Chilean Andes

Abstract

1. Harmonia axyridis has invaded many regions of the world, with negative effects on local biodiversity, and thus it is of global concern for biological conservation. Recently it has invaded central Chile, one of the world's biodiversity hotspots, where the abundance and richness of ladybird species, particularly native species in agroecosystems, have declined following its arrival.

2. Harmonia axyridis is particularly abundant in spring in the valleys of central Chile, but there is a dramatic decline in its abundance during the hot summer months.

3. This study reports the occurrence of this invasive alien species in the summer at high altitudes (3578m a.s.l.) in the Andes, which is the highest record worldwide. Individuals were observed on native cushion plants, in a unique environment rich in endemic species. Harmonia axyridis were active, reproducing and co-occurring with three other species of coccinellids.

4. The dispersal of H.axyridis and other coccinellids from the valleys to high altitudes could represent a mechanism to escape the adverse high temperatures during the summer, returning to the valleys in autumn. Our study highlights the need to study the impacts of invasive alien species across a range of habitats, including not only agricultural landscapes, but also extreme ecosystems.