This spring (2021) we have been noticing an increased number in symptomatic beech trees that have been confirmed as having beech leaf disease (BLD). BLD has been making its way through the east coast since 2012 when it was first spotted in Ohio. The causal agent of BLD has been determined as Litylenchus crenatae, a foliar feeding nematode that was first documented on Japanese Beech in Japan, but only causing mild symptoms. Here in the US, BLD has been found to cause mortality in our native American Beech (Fagus grandifolia) as well as cultivars in 6-10 years in large trees, and even more rapidly in smaller trees. The infection causes chlorosis in the leaves, which prevents beeches from photosynthesizing properly and adequately storing carbohydrates needed for overwintering. This also reduces their ability to defend themselves against other pests and pathogens.
While it is still unclear how the nematodes travel long distances, locally they may be spreading via water on tree trunks through rain, snow melt, or irrigation. They have also been found hitchhiking on arthropods like spider mites, which can be easily transported by wind up to a few miles. More research needs to be done to understand the pathways of spread, for instance, insect trapping on infected and non-infected trees.
Watch for these symptoms
- Dark banding/striping between beech leaf veins, which is especially apparent when held up to the light
- Leaf curling
- Leathery texture on leaves
- Aborted leaf buds, branches severely lacking leaves, reduced canopy
- Leaves that are smaller in size
- Yellowing leaves
- Twig and branch die back
- Suckering (small shrub layer of new beeches beneath a larger tree) — *may not be caused by BLD but oftentimes signals a stressed tree.
If you notice these symptoms, please take photos and send them along with location information to:
-Apps such as iMapInvasives, iNaturalist
-NYS DEC – email: foresthealth@dec.ny.gov or by phone at: 1-866-640-0652.
–You can also email us at LIISMA: invasive@liisma.org
While there are currently no known management practices for BLD infected trees, please help slow the spread by not transporting beech trees or firewood from known infestations, and by documenting any encounters you have with symptomatic trees
.
