Which symptom indicates damage from billbugs?

The symptom that indicates damage from billbugs primarily involves stems breaking easily when pulled. Billbugs, which are a type of weevil, target the grass and feed on the tissue within the stem. This feeding can lead to severe structural damage, compromising the integrity of the grass plants. As a result, when these stems are tugged or pulled, they may break more easily than healthy stems, indicating that the plants are weakened due to billbug activity.

Other symptoms like leaves turning yellow, the presence of small holes in the leaves, or wilting grass blades are commonly associated with various other pests, diseases, or environmental stressors rather than specifically with billbug damage. For instance, yellowing leaves often indicate nutrient deficiencies or environmental stress, while small holes in leaves could point to chewing insects like caterpillars or leafhoppers. Wilting grass blades can be a result of drought conditions or root issues unrelated to billbugs. Understanding the specific damage caused by billbugs helps in effective identification and management of these pests.