Every winter, teams of horticulture staff members scout a random assortment of our susceptible trees for the presence of the invasive Asian long-horned beetle (Anoplophora glabripennis). Maples, elms, willows, horse chestnuts, and poplars are some of their preferred hosts. We record the DBH of the tree, note the start time, and scan the trunk and each branch of a selected tree with binoculars, which is much easier when the trees are lacking foliage. We’re looking for any egg-laying sites chewed into the bark by the females, or exit holes from emerging adults after tunneling and feeding on the tree’s sapwood and heartwood. A single tree, tall enough and with a spreading crown, could take a group of three over an hour to scout, or a cumulative three work hours to check that specimen. Luckily, ALB has not been detected in the Arboretum. For the health and safety of our collections, we will continue to be vigilant in our yearly scour of the landscape for this destructive pest.
1815
Accessions on the susceptible tree list.
60–90
Trees surveyed per winter.
Rachel Lawlor is a horticulturist at the Arnold Arboretum.