These tiny pests can do a lot of damage in your lawn.
We often think of Bermudagrass as a tough and pest-free turf grass. But under the right conditions and with poor soil health, even this tough spreader can suffer pest damage. If you look very closely at the photo, you'll see a small white dot at the growing crown (base) of the stem. That is a Bermudagrass scale insect, Odonaspis ruthae.
Bermuda lawns that are subjected to too much shade, thatch build up, over-watering or extended drought are often damaged by Bermudagrass scale. These small insects resemble small moldy oyster shells. You'll find them at the nodes and crowns of the plant. These insects will suck fluids from the grass causing it to turn yellow and brown. Often, this damage is mistaken as disease damage. Again, shady areas that are stressed will be more likely to succumb to scale infestations.
While treatments can control the insects, as long as the environmental stresses remain (too much shade), it will be difficult to control the problem permanently.