Bee Sticks in the Name of Conservation

By Matt Bahm, Steve Walters, David Cappaert, Lauren Merrill, and Annie Joliff

All photos by David Cappaert

June 2020

Willamette daisy (Erigeron decumbens) was once found throughout the Willamette Valley in northwestern Oregon, but is now restricted to only a few scattered remnant populations. Conservation efforts have increased the amount of Willamette daisy on the landscape, but there is still much to learn to continue to improve restoration efforts. One of the issues facing the species is low seed production in populations, likely caused from the decrease in size and isolation of remaining populations. IAE has partnered with the Army Corps of Engineers, Eugene District to determine if crossing different populations of Willamette daisy will increase the amount of viable seed produced.

We designed a greenhouse experiment to help answer this question that involves growing Willamette daisy from different populations and conducting cross-pollination of the populations. This will help us determine if using pollen from different populations results in more viable seed than simply having pollen from the same population. Often in these types of experiments, scientists will use small paintbrushes to move pollen. While this can work, it isn’t always effective at moving large amounts of pollen and since we wanted to be sure that we were moving as much pollen as possible we wanted to try another method. Since we knew that pollinators are obviously very good at collecting large amounts of pollen, we decided that we should go with nature’s well-designed solution: the honey bee (Apis mellifera).

Willamette daisy in the field showing the different stages of flower development on the same plant

Willamette daisy in the greenhouse with the outer flowers reproductive

Since we felt that training bees to go only to the correct flowers for our experimental crosses would take just a bit too long, we had to try a different route. Working with the OSU Honey Bee Lab, we were able to obtain frozen bees that we then made into “bee sticks” that we will use to transfer pollen from flower to flower.

Photo of “bee stick” used to cross-pollinate Willamette daisy

Photo of a bee, covered heavily with pollen, on a bee stick

While we are just starting to conduct the experimental crosses, we are hopeful that our “bee sticks” will increase our chances of success. Although some worker honey bees did have to be sacrificed for this work, we are hopeful that this project will help improve restoration efforts for Willamette daisy, and ultimately put more resources for pollinators out in the landscape of the Willamette Valley.

Willamette daisy seed releasing from the flower head