We are moving into the spring season, which many of our hemlock news readers will know as the time when we shift away from rearing our Laricobius beetles and towards Leucopis silver fly research. During the spring seasons—around March and April—Laricobius adults are laying eggs. Those eggs hatch into larvae that drop off infested hemlock branches into the soil. In the lab, we simulate this process by collecting dropped larvae and placing them into soil containers where larvae can begin pupating. These soil containers are kept at a consistent temperature and level of moisture throughout the pupation process so that the beetles will be able to successfully pupate and emerge as adult beetles next season.
Adult beetles will die after they have laid all of their eggs, but some of the adult beetles are still alive and eating HWA by the time our larval collection numbers are tapering off. These late bloomers allow us to make a final beetle release to clear out our lab, to prepare for the arrival of silver flies and then for the emergence of beetles towards the end of the summer season. Last week, we released the 694 remaining beetles at Harriman State Park in the Lower Hudson region. We have released beetles at Harriman State Park before, so we hope that this year’s beetles will bolster any established population that may be present. Harriman has great condition for biocontrol releases, with trees that are still relatively healthy and lots and lots of HWA for our biocontrol bugs to munch.
Right, Top: Laricobius life cycle stages (larva, pupa, adult) under the microscope. Photo: Cornell Entomology
Right, Bottom: A Laricobius nigrinus release. Adult beetles are placed onto wooden shavings in the lab and transported to the release site. The shaving nest is then placed upon the branch of an infested hemlock tree. Photo: New York State Hemlock Initiative
As we begin to shift from lots of beetle work to lots of fly work, we are also taking some time to celebrate the lab’s accomplishments and thank our partners, volunteers, colleagues, and friends for all of the ways that they support our research. This year we are hosting an open house so that visitors can check out our lab and see what we do. Our doors will be open from 12:00 to 4:00 PM on May 15th at Cornell University’s Morrison Hall and visitors may come any time during that afternoon. We will be talking with you about what we do and giving tours of our lab spaces. We hope to you there!
A note about parking: If you would like to visit us on May 15th, there is a pay parking lot near Morrison at the corner of Judd Falls Road and Tower Road across from the Dairy Bar. For more information about campus parking please visit Cornell’s visitor parking page.