Botanical Treasures from Duke's Hidden Library

Webworm

In 2011, eighty publications cited specimens from the Duke University Herbarium. Specimens stored in herbaria enable exciting scientific research that sheds light on natural history, One such research project yielded insight into the historical “rivalry” between the parsnip and the webworm.

Wild parsnips made the journey from Europe to North America more than 400 years ago, leaving behind  the parsnip webworm, an insect that would consume the parsnip’s reproductive parts. Without its archenemy around, the parsnip plants  produced lower amounts of furanocoumarins over time, losing their chemical defense against webworms. When the webworms finally caught up with the parsnips in North America around 1869, parsnips rapidly evolved increased furanocoumarin content in response. Capturing this evidence for co-evolution was made possible by analyzing herbarium specimens of wild parsnips collected over the last 150 years.