Scientists from the Connecticut Agricultural Experiment Station have identified beech leaf disease on American beeches at three locations in Greenwich, New Canaan, and Stamford.

This disease, which can kill trees within seven years of detection, was first discovered in 2012 in Ohio, and later found in Pennsylvania, western New York, and Ontario, Canada. With surveys underway to assess the extent of the disease in Connecticut, the disease appears to be limited to Greenwich, New Canaan, and Stamford.

The disease is caused by a nematode, Litylenchus crenatae, a type of roundworm, subspecies mccannii. Symptomatic leaves tested positive in July. The nematode appears to cause disease only on American (F. grandifolia) and European beeches (F. sylvatica).

The symptoms on beech foliage, best observed from below looking up into the canopy, are characterized by dark striping between leaf veins.

How the disease develops, is spread, and how it may be controlled are the subjects of ongoing studies.

Members of the public are encouraged to report any findings of similar symptoms on beech trees to scientists Robert Marra ( or James LaMondia (