A local butterfly, long considered common, is center stage

Scientist Marcus Kronforst chases butterflies in a Hyde Park garden.
Scientist Marcus Kronforst chases butterflies in a Hyde Park garden.

Staff Writer

One University of Chicago research team is spending its summer catching small butterflies in the neighborhood.

Hyde Parkers might see Marcus Kronforst, a professor in the department of Ecology and Evolution, frantically swinging a butterfly net out on Midway Plaisance or in community gardens.

The team is catching the white cabbage butterflies, smallish bugs with two black dots on its wings. They are common across the globe and easy to find in gardens, parks and all over Hyde Park.

The team is capturing hundreds of butterflies to study how they interact with Arabidopsis, a genus of flowering plants in the mustard family, as common globally as the white cabbage butterfly is.

Arabidopsis contains thale cress, one of the few plants that have had its entire genome sequenced. Because the white cabbage butterfly eats many plants within the Arabidopsis family it is an excellent candidate to study the way the bug and plant interact on a genetic level.

“This is an antagonistic relationship,” Kronforst said. “The plant does not want to be eaten.”

In the first phase of the experiment researchers measured how much one strain of caterpillars eat on 100 strains of the Arabidopsis. In the second half researchers are testing how much 100 strains of the caterpillars eat of one strain of Arabidopsis.

“We’re doing this project because there’s all this amazing genomic research on the plant,” Kronforst said. But research on the white cabbage butterfly is lacking.

The study focuses on how Arabidopsis reacts on a genetic level when the butterflies begin to eat or lay eggs on the leaves. Results could lead to transgenic plants that don’t need pesticides and a greater understanding of the evolution of both the plant and bugs.

Catching hundreds of the butterflies is a challenge. The researchers need to collect 100 females. While in captivity they breed 50 percent male and 50 percent female; catching them in the wild tends to yield significantly more males.

The wild-caught butterflies are then taken back to the university’s greenhouse where each individual bug needs to be fed by hand. The bugs are allowed to mate and the females lay eggs on Arabidopsis plants.

Photographs are taken of the plants before the eggs are lay and after the caterpillars have grown. Lab manager and senior researcher Sumitha Nallu then uses software that measures the area of each of the hundred leaves the insects eat.

Each generation takes between four and five weeks to grow from egg to adult.

The team is searching in Hyde Park primarily but to catch a greater number of genetic variations in the bugs has traveled to Schaumberg and southeastern Michigan.