What symptom can indicate an infestation by the Emerald Ash Borer?

Vertical bark slits are a significant symptom indicating an infestation by the Emerald Ash Borer. These slits occur as a result of the adult beetles tunneling through the bark and laying eggs beneath the surface. As the larvae develop, they create distinctive serpentine galleries underneath the bark, which can cause the bark to split. This visual cue, along with other signs like dieback of the canopy and increased woodpecker activity (as they feed on the larvae), can help in identifying the presence of this invasive pest.

In contrast, dark bark, excessive flowering, and colorful leaves do not specifically relate to the symptoms of Emerald Ash Borer infestation. Dark bark can occur for various reasons unrelated to pests, while excessive flowering and colorful leaves typically indicate healthy growth rather than infestation or damage. Thus, understanding these symptoms can aid in timely detection and management of the Emerald Ash Borer, crucial for preserving ash tree populations.