BHSU biology professor comments on large population of butterflies this year

Dr. Holly Downing, professor of biology at Black Hills State University, says the large migrating population of Painted Ladies this year is likely due to favorable weather conditions causing less die-off or greater reproduction than usual.

Move over Yellow Jackets. The butterflies are taking over campus at Black Hills State University.

Dr. Holly Downing, professor of biology at Black Hills State University, who studies social insects, is among many in the state who have noticed the increase of butterflies this year. She suspects the increase of orange-and-black-winged fluttering butterflies seen on campus and throughout the Black Hills this season are Painted Ladies, Vanessa cardui.

"The large migrating population of Painted Ladies this year is probably due to favorable conditions that have caused less die-off or greater reproduction than usual," says Downing.

According to Downing, Painted Ladies are migratory butterflies that are widespread throughout the world. They feed on and lay eggs on a wide variety of plants, which explains why the flora at BHSU is especially attractive to them.  

"The Painted Ladies we are seeing on campus are probably butterflies that emerged north of here. They are headed south for the winter. Adult butterflies can hibernate farther north, but only successfully during mild winters," says Downing.

The butterfly days of autumn are numbered, though. Downing says Painted Ladies usually travel south in September to overwinter.