When bio is not green: the impacts of bumblebee translocation and invasion on native ecosystems.

Abstract Adequate pollination is fundamental to optimize reproduction and yield of most flowering plants, including many staple food crops. Plants depending on insect pollination rely heavily on many wild species of solitary and social bees, and declines or absence of bees often hampers crop productivity, prompting supplementation of pollination services with managed bees. Though honeybees are the most widely deployed managed pollinators, many high-value crops are pollinated more efficiently by bumblebees (Bombus spp.), prompting domestication and commercial rearing of several species. This led to a blooming international trade that translocated species outside their native range, where they escaped management and invaded the ecosystems around their deployment sites. Here, we briefly review the history of bumblebee invasions and their main impacts on invaded ecosystems, and close by discussing alternatives to the use of commercially reared bumblebees to enhance crop pollination. As evidence of widespread negative effects on local ecosystems of bumblebee invasions builds up, bumblebee trade adds to the list of examples of "biological" strategies devised to solve agricultural problems that ended up being far from the "green," eco-friendly solutions they were expected to be.