The decline of Monarch butterfly populations over the past two decades has received much attention from scientists. However, recent surveys of the Monarch population in the Midwest have not been showing dramatic decreases.
Monarch populations are thought to be tied to the disappearance of milkweed, the only plant on which Monarchs lay eggs. Iowa State University assistant professor in ecology, John Pleasants says Monarch populations in the Midwest may appear stable because counts are taken in open areas where butterflies can find milkweed.
“The key thing that has happened over the past two decades is Monarch activity has shifted out of agricultural fields into these non-agricultural areas where the censuses are made.”
Pleasants says his research indicates the Midwest needs as many as one-point-six billion new milkweed stems to help bring back the Monarch butterfly population.
“Yes, it’s the loss of milkweed that’s responsible, and yes, all these efforts by many, many people to go out and try to put milkweeds on the landscape, that’s a good thing, it has a sound scientific basis.”
Pleasants made his comments on IPR’s Talk of Iowa. Also joining host Charity Nebbe on the program are Donald Lewis, Professor of Entomology at ISU; and Richard Jauron, ISU Extension Horticulture Specialist.