Project Results

I'm so excited to share our recent publication highlighting the work you helped fund. We found that bumble bees will avoid foraging for food near wool-carder bees. But luckily, we found no effects of this avoidance behavior on bumble bee fitness (reproduction or growth). Thank you again for supporting this work! 

About This Project

Is a recently introduced invasive species, the European wool-carder bee, threatening our native bumble bees?

Male wool-carder bees use evolved weapons on the base of their abdomen to ram into bumble bees trying to gain access to flowers. This project will determine if these interactions are hurting bumble bee lifetime reproductive success.

Ask the Scientists

What is the context of this research?

Invasive species dramatically reshape their invaded landscapes and restructure interactions between native species. In North America, the European wool-carder bee (Anthidium manicatum), a recently introduced non-native species, threatens the well-being of native bees.

Male wool-carder bees defend patches of flowers using evolved weapons on the base of their abdomen to ram into other bees trying to visit the defended flowers. And the cost of these interactions to other bees is high - often severe injury or even death. Of our native bees, bumble bees receive the majority of attacks from wool-carder bees. Yet we do not know the impact of these attacks on bumble bee populations.

What is the significance of this project?

Bumble bees are declining drastically. Some previously common species are estimated to have only 4% of their original population surviving today. We depend on bumble bees to pollinate crops – including tomatoes, peppers, blueberries, and more. Bumble bees perform a special pollination behavior called buzz pollination, which many native crops depend on. Without bumble bees, the sustainability of US agriculture would be in question.

The greatest threat to bumble bees is habitat destruction - urbanization, agriculture and introduction of invasive species, such as the wool-carder bee. Yet we don't know the extent of impact wool-carder bees have on bumble bee decline. Therefore, my research will determine long term effects of wool-carder bees on bumble bees.

Projects such as this are necessary to determine the impact of this invasive bee on our native ecosystem. With the information provided by this project, we can make recommendations about wool-carder bee control and ecosystem rehabilitation.

What are the goals of the project?

My previous research determined that bumble bees actively avoid visiting flowers near wool-carder bees. But we need to establish if wool-carder bees will have long term fitness effects on bumble bees. To do this I will measure fitness in the following ways:

1. Use 12 screened enclosures filled with flowers to subject 12 bumble bee hives to 2 treatments – enclosures with wool-carder bees, and enclosures without wool-carder bees (controls)
2. Measure bumble bee hive growth over the season (weekly weight of hives)
3. Perform bumble bee demographics (number and size of bees, and number of future queens) at the end of the season