What causes yellowish spots on grass stems?

Yellowish spots on grass stems are commonly caused by chinch bugs, which are small insects that feed on the sap of grasses. When chinch bugs puncture the grass stems, they remove nutrients from the plant, leading to discoloration. This feeding can result in yellowing or browning spots along with a decline in plant vigor, which eventually may lead to the death of sections of the lawn if left untreated.

In grass affected by chinch bugs, these yellowish spots often appear first in sunny areas of the lawn, as the bugs thrive in hot, dry conditions. The presence of these insects can also attract secondary issues, such as fungi, which can further complicate the health of the grass. Thus, identifying chinch bugs as the culprits behind yellowish spots is essential for proper pest management and lawn care.