Have you noticed anything strange happening to black oaks around the island? Recently, a wave of oak gall wasps have spread throughout northeastern coastal states, ravaging a single tree species - the black oak.
Join us for an update on the health of the island's black oaks with scientists Cameron Freedman-Smith and Dr. Joe Elkinton.
The oak gall wasp was found to have reached Tuckernuck and Nantucket in 2014. Nantucket’s history of deforestation and isolation has resulted in younger, less diverse woodlands than many on the mainland. Our scattered “older growth” trees are even more precious. Of these, black oak has become one of the most important due to its salt and wind tolerance, value for wildlife, and usefulness as a landscape tree.
In 2016, the Nantucket Conservation Foundation invited Monica Davis, at the time a University of Massachusetts at Amherst PhD student, and her advisor, Dr. Joe Elkinton, to examine Nantucket black oaks in their regional study of the oak gall wasp, since named Zapatella davisae in Davis' honor. This tiny insect was identified as the cause of massive black oak damage from Long Island to Cape Cod. Initially Davis and Elkinton observed that Nantucket was still in an early stage of invasion, presumably because the wasp took longer to arrive here on the island. Since then, the number of heavily damaged trees has continued to grow as the new pest gained a foothold in our forests and yards.
In response to these concerns, the NCF and the Nantucket Land Council partnered to bring another of Dr. Elkington’s students, Cameron Freedman-Smith, to the island to identify the insects emerging from Nantucket twig samples. On the Cape and Long Island, researchers saw a surge in beneficial insects (parasitoid wasps) that fed on the oak gall wasp and gradually brought it under control. To see whether this is happening on Nantucket, the researchers are evaluating both gall wasp densities beneficial parasitoids (the insects that prey on the gall wasps and reduce their numbers) to help islanders better understand what is happening to our black oaks and inform our management decisions. Join us to hear the most recent results from this project and learn about the fate of some of Nantucket’s oldest forest residents.
Co sponsored with the Nantucket Conservation Foundation.