What type of damage is caused by armyworm larvae?

Armyworm larvae are known for their feeding habits that primarily involve consuming the terminal leaves of various plants. This feeding behavior can lead to significant defoliation, which means that they strip the leaves off of the plant, ultimately affecting the plant's ability to photosynthesize. The loss of terminal leaves not only reduces the plant's overall health but can also impact growth and yield, particularly in crops.

In contrast, other types of damage described in the options do not accurately reflect the behavior of armyworm larvae. For instance, they do not primarily target roots, and their feeding does not involve sucking sap or exclusively damaging flowers and buds. Understanding the specific feeding patterns and impacts of armyworm larvae helps in developing effective control strategies for managing their populations and mitigating crop damage.