Emily Geest found a way to combine two passions, parasitism and butterflies, in her master’s program at the University of Nebraska at Omaha.
Geest is monitoring milkweed gardens to assess the effectiveness of the gardens as conservation strategies. She determines if monarchs are coming to them, if they are laying their eggs there and if the eggs are surviving from egg to adult. She also keeps track of how many of the butterflies are parasitized by flies.
Monarchs, especially ones within the Eastern population, have had a population decline of about 80 to 90 percent since 1995, Geest said. A lot of that is because of habitat destruction. Milkweed gardens have helped re-establish their habitat.
The monarchs reached their lowest population in 2012 because of a drought that reached across the Midwest. Their numbers have gone back up, but are nowhere near where they were before 1995.
“We don’t know if the increase is a long-term trend or if it is just because the weather has improved,” Geest said.
Geest monitors 13 gardens. About half of them are residential gardens, and the other half are conservation sites which are known as prairies. She visits each site every four days. Last year, she managed all of the sites on her own, but this year some undergraduates are helping her monitor the sites.
At the site, she counts all of the milkweed and writes down all of the species of milkweed that are present. Then, she takes tallies of the eggs. Depending on what stage in which the caterpillars are, she takes them back to the lab.
The species of caterpillar she is studying has five instars, or growth stages. She takes tallies of each instar, and all caterpillars at their fourth or fifth instars are brought back to the lab. The biggest threat of mortality in the later instars is parasitism. They have reached the maximum amount of exposure to the fly by instar four, so Geest is able to take them to the lab and monitor whether they will be parasitized.
Geest visits her lab in Alwine Hall every day and feeds all of the caterpillars. If they are parasitized, she waits for the maggots to come out of the caterpillar and then counts them. If the caterpillars turn into a chrysalis, she moves them farther down the table so they don’t get disturbed. When they come out of the chrysalis as butterflies, she moves them into a butterfly cage for a day so their wings can dry. The next day, she brings the butterflies back to their original site.
Geest said her favorite aspect of the project is working with the public.
“Everyone loves monarchs. They know what monarchs are,” Geest said. “If you study birds you would have to explain what kind it is, but when they hear monarchs, people say, ‘Oh it’s the symbol of Papillion!’ Everybody loves them and always wants to talk about them.”
After graduation, Geest said she hopes to get her Ph.D. work as a research biologist.
She wants to focus her research on grassland butterflies.
“The grasslands have been one of the biggest habitat losses,” Geest said. “All of the butterflies are suffering, not just the monarchs.”
Though she is excited to earn her Ph.D., Geest said she will miss UNO.
“When I came here, I loved everything,” Geest said. “I loved my advisors. I loved the biology department. It all felt right.”