Emerald Ash Borer

Natural Habitat

The primary habitat of the emerald ash borer is ash trees (Fraxinus species) found in forests, urban landscapes, and nurseries. They are native to northeastern Asia but are an invasive species in North America and parts of Europe.

Diet & Feeding

The adult emerald ash borer feeds on ash tree leaves, causing little damage. The larvae, however, feed on the phloem and cambium layers of ash trees.

Behavior Patterns

Emerald ash borers are active during the day. Adults emerge from ash trees typically from late May to early July, and they primarily feed on ash leaves. Females lay eggs in bark crevices. Larvae bore into the tree's phloem and cambium, creating 'S'-shaped galleries as they feed, which disrupts the tree's ability to transport water and nutrients. The life cycle usually takes one to two years.

Risks & Benefits

Potential risks: The emerald ash borer is a highly destructive invasive pest that has killed tens of millions of ash trees in North America, causing significant ecological and economic damage. It poses a severe threat to ash tree populations, which are a valuable component of many ecosystems and urban forests. Potential benefits: None for the invaded ecosystems; they are an invasive species.

Identified on: 8/22/2025