Emerald Ash Borer

Emerald Ash Borer The emerald ash borer (Agrilus planipennis) is a green jewel beetle native to north-eastern Asia that feeds on ash species. Females lay eggs in bark crevices on ash trees, and larvae feed underneath the bark. It is an invasive species and is highly destructive to ash trees native to North America.

By 2019, the ash borer was destroying most of the ash population in Pennsylvania. The primary cause appears to be due to climate change and the warmer winters. After 400–500 accumulated degree-days above 50 °F, adults begin to emerge from trees in late spring, and peak emergence occurs around 1000 degree-days.

The beetles also appear to be taking advantage of weakened tree health attributed to ozone, acid rain and moisture.

The following pictures are from Blue Mountain, Pennsylvania in the summer of 2019.

Hundreds of Standing Dead Ash Trees Killed by the Emerald Ash Beetle
Hundreds of Standing Dead Ash Trees Killed by the Emerald Ash Beetle

Mountain Side Cleared of Dead Ash Trees
Mountain Side Cleared of Dead Ash Trees

Stack of Dead Ash Wood
Stack of Dead Ash Wood

The Decline Of Trees