Anyone? Please! I fear we are running out of time to treat our patches.

You don't say where you are, but in ;lower Michigan/northern Ohio, this is the tail end for applying Grub-ex

Here is a good article on grub control, but remember it is aimed at Michigan, so you'll need to adjust.

Here is a link that might be useful: Grubs

To my knowledge if you are concerned about the lawn (I'm assuming since you posted it in the lawn care forum) you are too late for now. The majority of grub damage is done in the late summer and fall when the newly hatched grubs are actively feeding on the roots of the grass. Right now you basically have developed grubs just waiting to come up and eat everything in sight (but that won't harm your lawn).

So if you care about the grass wait until later in the year, but if you care about other things you may still have a bit of time but I cannot personally recommend a product (I have used for the past 2 years milky spore but that is not a quick fix, would not help in your particular situation of killing them now, and is likely impractical over such a large area).

Goodluck.

We're a long way from where you are, but our lawn care guy said fall is best as far as killing grubs but they've seen a lot of them this spring so they're also treating now.

Sod webworms are caterpillars. You can control them naturally by allowing wasp nests to form under your eaves. These "paper wasps" create nests that are like paper. Inside each cell of the nest they lay an egg and insert a paralyzed caterpillar for the newborn larva to eat. These wasps are magical creatures. As long as you leave them alone, they will quickly learn who you are and your habits and leave you alone. This can take a lot of conditioning on your part so you don't dance around waving your arms when they approach you. Last summer I had a wasp population of about 300 all around my house. They all knew my routine so I could take amazingly close up pictures like this without them paying any attention.

{{gwi:95003}}

That was from about 1.5 inches away, so they really will leave you completely alone. And they will clear your property of all caterpillars.

As for grubs, it has been reported that they rarely strike the same neighborhood two years in a row. The time to watch for them is after you notice beetles swarming your porch lights. Make a note of when that is and, about a month later, inspect your lawn. Dig up a full square foot of soil about 2 inches deep. If you find more than a dozen grubs, then you have a problem. Normal lawns should tolerate a dozen grubs per square foot. If you have fewer than that, you should be good for the rest of the year because some will not survive. If you have more, then spray away.