How are spongy moth infestations typically identified?

Spongy moth infestations are primarily identified by the presence of caterpillars. During their larval stage, these caterpillars emerge from egg masses in the spring and begin to feed on the foliage of trees. They are easily recognizable due to their distinct appearance, and their feeding can cause significant defoliation, which is a clear indication of an infestation. Monitoring and observing these caterpillars on trees can help in assessing the severity of the infestation and implementing management strategies.

While other life stages such as adult moths and egg masses can also indicate an infestation, the caterpillar stage is particularly crucial for identifying active feeding and can lead to immediate action to mitigate damage. Fallen leaves might indicate damage caused by the caterpillars, but they do not directly identify the presence of spongy moths or their life cycle stages. Thus, recognizing caterpillars is the most effective method for identifying an active infestation.