Subsequently it was discovered that a fungus, then identified as Neonectria ditissima, was in fact killing the trees infested by the scale.

By 1932, the scale and its associated Neonectria fungus had spread to many areas of the Maritime Provinces and parts of eastern and south central Maine.

It continues to spread in North America and is now found in Quebec, Ontario, New England, New York, New Jersey, Pennsylvania and West Virginia.

[5] Attempts are being made to discover the geographic origin of beech scale in order to try to identify any natural enemies that might hold promise for its biological control.

From these studies and associated ribosomal DNA analysis, it seems likely that the pest originated in the region of northeast Greece, northern Iran, the Caucasus and the Black Sea drainage basin on the host beech subspecies F. sylvatica orientalis.

Persistent severely cold weather may kill beech scale and air temperatures of -37 °C have been shown to be lethal to insects not protected by snow.

This may be partly due to the fact that trees with smooth bark provide fewer cracks and crevices in which the scale insect can flourish.