Pollination and communication ecology of exotic spreadings

Bees are invaluable for nature and to us humans due to their ability to pollinate. They play a central role in the functionality of ecosystems and food security. Bees search for suitable host plants that offer nectar and/or pollenfood for the adult bee and its offspring. To attract bees, plants use especially specific colors and floral scents. Over millions of years, native bees and host plants have adapted to gather food efficiently and to be optimally pollinated, respectively. In recent decades, bees have increasingly been introduced into regions that are foreign to them. These introduced bees encounter unfamiliar plants in their new environment. To survive, exotic bees must find suitable flowers that can serve as new food sources. So far, science knows little about the relationships between new host plants and introduced bees or how these new host plants are found. This study addresses these questions for the first time by examining plant signals (colors and scents) and their effects on Europes first introduced bee, Megachile sculpturalis, also known as the sculptured resin bee. Originally from East Asia, this bee has successfully spread in Europe and North America over the past decades. In Europe, it visits both native and introduced plants, such as the invasive kudzu. Kudzu also originates from East Asia, where it is the primary food source for the sculptured resin bee. In Europe and North America, kudzu causes devastating damage by rapidly overgrowing infrastructure and native plants. A mutualism between kudzu and the sculptured resin bee could lead to the rapid spread of both organisms, negatively impacting native biodiversity. This study investigates whether the sculptured resin bee pollinates kudzu in Europe, and studies the impact of this potential pollination on the invasive plant and how the bee finds kudzu and native plants in Europe. The researchers of the Paris Lodron University of Salzburg involved use flight cages, spectrophotometers and (chemical) ecological approaches, among others, to investigate these research questions. Stefan Dötterl brings years of experience with olfactory and visual plant signals, and Julia Lanner has been working for several years on Hymenoptera introduced to Europe.