Sod Webworms are Active in Pinellas County and Causing Damage to St Augustine Grass Lawns

Due to the mild winter, the Sod Webworm activity has started early. Sod webworm damage is circular in appearance, can be any size from a few inches to an entire lawn and often a distinct grey or tannish color. The most distinct symptom is the lawn is shorter in the damaged areas – this is because the sod webworms are actually mowing the St Augustine grass.

Sod Webworm Biology

Sod webworms are small half inch long caterpillars that cut St Augustine grass leaves off at the bottom of the leaf. This gives it the mowed appearance. Then the leaf that has been cut turns grey to tannish brown giving the damaged area a distinct color.

If you look closely at the damaged area you will see the cut marks on leaves and stems where the sod webworm is feeding. Looking further into the canopy you’ll find the little green caterpillars curled up at the soil surface.

The sod webworm is the larva of those little tan moths you see flitting about your lawn. The moths do no harm – except laying eggs. The eggs hatch into sod webworms. And when there is enough sod webworms, they mow your lawn for you.

No Need to Panic over Sod Webworms

No need to panic over sod webworms. St Augustine will fully recover from sod webworm damage – unless you let it go untreated all summer. The reason they appear is a timing issue – the moths lay so many eggs and there is constant hatching and regeneration that sometimes they are missed by regular lawn sprayings.

For the DIY

The best treatment is to spray the damaged area with an insecticide – just about any will do – and let the sod webworms feed on the treated grass overnight. Within a week the grass will return to a normal appearance. Treat as often as you see damage.

For My Customers

I anticipated early arrival of all pests and started treating for them in February – so no need to do anything. However, should you see any suspicious areas, feel free to call and I’ll take care of the problem.