ShadyGreenThumb said:We have Tropical Sod Webworms if that makes any difference?
It doesn't make a difference, they still eat the grass blade not the roots according to this U of Florida page on Tropical sod webworm. Have you seen the caterpillars?
"......The first four larval stages (instars) are ‘window feeders’, i.e. they only feed on the upper surface of grass blades, and so the injury they cause is often overlooked. Fifth and sixth instars can severely damage grass by chewing entire sections off the leaf blade. Larval feeding occurs at night, and larvae hide in the thatch during the day. Caterpillars prefer dry and hot grass areas. Early damage is hard to notice and creates a ragged appearance, but as larvae grow, they consume considerable quantities of grass before pupating. Grass may recover if infestations are not too severe......"
http://entnemdept.ufl.edu/crea...
Edited to add this link from Texas Cooperative Extension which says the tropical sod webworm feeds on the leaves while they're still attached to the plant whereas the other sod webworms in Texas detach the leaf to eat it:
http://harris.agrilife.org/fil...
