Invasion success of European bumblebees in SW South America - Similarities and differences with Oceania and conservation implications (poster)

MORALES CAROLINA LAURA; AIZEN MARCELO ADRIAN

San Carlos de Bariloche

Congreso; VI Southern Connection Congress (Libro de resumenes publicado Online); 2010

Southern Connection , CONICET, INTA y UNCOMA

European bumblebees Bombus ruderatus and B. terrestris invaded NW Patagonia (Argentina) after their introduction in Chile for crop pollination. Since 2000, I recorded the flower species visited by both invasive species, and by the native congener Bombus dahlbomii. I explored the use of floral resources by the three bumblebee species. Both alien bumblebees thrived in disturbed and undisturbed habitats, whereas the native bumblebee tended to be more associated to undisturbed habitats. The short-tongued B. terretris was highly generalist, visiting both native and alien flowering species, resembling the distribution and floral use by this species in invaded areas of Tasmania and New Zealand (NZ). The long-tongued B. ruderatus was more specialist than B. terrestris, as reported for NZ. However, in Argentina B. ruderatus foraged on many native species, which contrasts with the exclusive exploitation of floral resources from alien species in NZ. This difference might relate to the availability of a diverse native assemblage of typical “bumblebee- flowers”. These flowers with long corollas and concealed nectar were pollinated by the long-tongued B. dahlbomii. The interplay between different evolutionary trajectories, resulting in disparate morphological flower-pollinator constrains, and habitat disturbance might influence the invasion success of introduced pollinators. Understanding all these factors can increase our ability to predict the impact of bumblebee introductions.