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How does an invasive bee impact our native pollinators and plants?


My dissertation research looked at the impact of an invasive bee, the European wool-carder bee, on native pollinators and plants. I used an interdisciplinary approach to provide the most comprehensive assessment of this invasive species in North America to date.  

The European wool-carder bee, Anthidium manicatum, was first seen in North America near Ithaca, NY in 1963. But now, it can be seen across the country. Wool-carder bees are highly successful invaders, with additional established invasive populations in South America, Asia, and New Zealand. 

Current known distribution of Anthidium manicatum in North America (from

Male wool-carder bees are highly aggressive and actively defend flower patches to entice female wool-carder bees to visit the flowers they defend. Female bees need to visit flowers to collect pollen and nectar to eat, and plant hairs (called trichomes) for their nests. To defend flowers, males use spines on the base of their abdomen to ram into other bees trying to access the flowers. This can lead to severe injury or even death to the attacked pollinator. The most commonly attacked bees are honey bees and bumble bees. 

Female wool-carder bees are also causing trouble in their invaded habitat. The plant hairs they collect for nesting material are used by the plants for water regulation and herbivore defense. Female wool-carder bees are also thought to be poor pollinators as they visit many different flowering species in sequence, causing pollen to be transferred between species - which is bad for the plants. Plants benefit from pollinators that visit the same species sequentially. Bumble bees and honey bees do this, which makes them optimal choices for agriculture pollination services.

Male wool-carder bee resting on my hand. Check out those spikes at the base of his abdomen!

Great video from Team Candiru showing wool-carder bee behavior

Female wool-carder bee collecting nesting material (trichomes) from a lamb's ear plant (Stachys byzantina)