While Senecio triangularis, native to Western Oregon, was not the intended hostplant of the introduced cinnabar moth, it has been supporting moth populations for decades.
Invaded places are not broken spaces
“It was some of the hardest work I have done,” says this week’s guest, Katarina Lunde recounting her arduous work interning with the Nature Consortium in the Duwamish region of Seattle. Katarina was passionate about her work in conservation ecology, spending countless hours leading groups of volunteers in restoration projects and educating the community about the restoration sites. But it was somewhere in the bone-chilling cold tearing out invasive species like the Himalayan blackberry and English ivy that Katarina had a shift in perception – these spaces were not broken. Katarina realized that informed decisions could tip the scales in the right direction in these vulnerable spaces. There was still hope to be found in the midst of these invasions. The desire to study ecology more deeply led Katarina to pursue a master’s degree in plant ecology with Dr. Peter McEvoy in the Department of Botany and Plant Pathology at Oregon State University.
Learning to tip the scales
In the 1920s, tansy ragwort (Senecio jacobaea) was first observed in the Portland, Oregon. This introduced, noxious weed, was causing severe liver failure and even death for grazing cattle and deer. The major economic implications on livestock prompted the Oregon Department of Agriculture to intervene. By the 1960s, the cinnabar moth (Tyria jacobaeae) was released as one of three insect biological control agents. The role of the cinnabar moth was to reduce tansy ragwort populations by depositing their eggs on the underside of the leaf and allowing newly hatched caterpillars to feed on and eventually kill the plant. However, there was an unintended consequence. When these very hungry caterpillars were released in the mountainous Cascade region, they found that a closely-related native plant species, arrowleaf groundsel (Senecio triangularis), was also quite appetizing.
Cinnabar caterpillars strip late-season Senecio triangularis stems of foliage. Luckily, most plants will have set seed and stored energy before the caterpillars reach peak feeding stages.
Despite this outcome, the release of the cinnabar moth has been largely viewed as a success, even though this biocontrol agent likely would not have been released under current standards. This system does then provide an ideal model system to identify long-term risks and benefits of biocontrol use. When it comes to biological invasions, the cost of inaction is often too high, so what are the risks and benefits?
Katarina Lunde installs experimental plots at a field site with the help of fellow lab members. She measured Senecio triangularis seedling recruitment under seed addition/reduction scenarios to assess potential impacts of seed loss due to cinnabar moth herbivory.
By studying seed loss and plant recruitment – do more seeds equal more plants? – on Marys Peak in Oregon’s coastal range, Katarina has been able to assess the risk that cinnabar moths pose on native plant survival. The answers are nuanced, of course, as this deals with a dynamic natural system, but Katarina’s work is allowing for better questions to be asked that will in turn better inform decision making regarding biological controls.
Finding the perfect fit
Katarina studied plants and plant systematics at Oberlin College where she obtained a bachelor’s degree in biology and creative writing. With student loans to pay off and a desire to find a career that fit her unique abilities and interests, Katarina spent six years working in fine dining and exploring future career paths in Seattle, WA, volunteering with various non-profits. Through her restoration program internship with the Nature Consortium, she was finally able to hone-in on the field of plant ecology. Katarina is currently nearing the end of her master’s program and seeks to apply her newly learned skills in an urban conservation and restoration setting, where she can continue to ask questions and interact with her work in a tangible way.
Katarina’s research has been supported by a NIFA grant and several awards from agencies that focus on native plant restoration and conservation, including: the Hardman Foundation Award, the Native Plant Society of Oregon, and the Portland Garden Club.
Join us on Sunday, November 18 at 7 PM on KBVR Corvallis 88.7 FM or stream live to learn more about the nuance of biological controls and Katarina’s journey to graduate school.
