Thanks Decklap, but there is no scouting to do now - if I had grubs last year (which I doubt since I had killed off my old lawn when they would have been feeding heavy and I don't think they would have made it - they should be gone and flying around by now anyway. Next opportunity for scouting would be early September, in which case, if I have them, I would need to use Dylox or something even worse, which I really don't want to do. I would rather use Imidacloprid as a preventative than Dylox for anything, for the sake of saving at least some of my earthworms. Joepyeweed, if I had never had a lawn completely destroyed by grubs I would give the nematodes a shot. I still may do so someday, but am just not there yet. The problems I have read about unreliable product/packaging/whatever are just too scary for me right now, with my brand new lawn and recent memories of massive grub damage.

Beneficial Nemetodes are the way to go. Beneficial Nematodes - Organic Insect Control Beneficial nematodes are underground pest hunters that control over 250 different species of insects that spend some part of their lives underground. They are a very efficient organic insect control method and kill most insects before they become adults. This includes lots of common lawn and garden pests such as grubs, fleas, mole crickets, japanese beetles and weevils. Beneficial Nematodes - Just what are they? The beneficial nematode is a small microsopic worm that lives below the soil. The picture seen here is of a juvenile nematode called a scarp. It is generally clear or white in color and has no segments like earthworms do. There are over 20,000 different kinds of nematodes that live in the soil and a small handful of dirt will generally contain thousands of them. Nematodes are considered parasites and can affect a number of different plants and animals. Some species of nematodes are considered pests, but these are not the same species of beneficial nematodes used to control insects. We recommend that a combination of beneficial nematodes be applied for organic insect control (Steinernema and Heterorhabditis), these are actually two different strains of beneficial nematodes which are parasites to other insects and spend their lives hunting and killing them. These nematodes will not control or kill other types of nematodes already in the soil. How effective are nematodes as natural predators? When a beneficial nematode attacks an insect larvae or grub it enters the body of its host. Generally within 48 hours that host insect will either die, be physically altered or unable to produce. The Steinernema and Heterorhabditis strains of nematode carry a bacteria that generally kills its host insect in quick fashion. The beneficial nematode then moves onto another host. What sort of conditions does it require? Beneficial nematodes live in almost any soil, but they prefer moist soil

I'm going to assume you didn't read the directions on the product before applying it. Like all the other contact killers, it is only effective when the grubs are young or right at the surface. That would have been June or July in your region. You aren't going to have any luck treating them in Sept and Oct. As the soil temperature drops, they head deeper and deeper and the product just doesn't get down to them. If you have dead grass, you will need to reseed or resod those areas. You are cutting it close for seeding in your area. You have a shot still if we have a mild fall, but you never know with weather.

So here is an update. I did buy beneficial nematodes. First batch was the Steinerneima Feltiae from Amazon (Scanmask is the company). Weeks later I see no difference. I even set up a rubbermaid 18 gallon bin filled with 4-5 inches of compost that was moist and used the remainder of the beneficial nematodes mixed in the compost well and then I introduced several grubs and mealworms expecting them to be dead in 48 hours or so. Weeks later the worms are still alive and so are the grubs, so I am guessing the beneficial nematodes weren't even alive. Before I saw the lack of results from the first batch, I bought 2 other varieties from buglogical.com (Heterohabditis and the Steinernema Carpocapsae). With the 3 different strains of Beneficial Nematodes I was expecting joy but several weeks later I still see no difference. With these 3 varieties I should not still see ant mounds or slugs or the grubs. By the way I ordered 50 million of the last 2 varieties in which they claim 50 million would cover a half acre. The area I treated was less than 1/10 of an acre, heck probably 200 square feet. Using 2 of the 50 million batches is would effectively cover a whole acre and I still don't see results in a small 200 sq foot area which tells me these things weren't alive. I also started 2 other containers with compost and added 2 different strains in each container and added mealworms and grubs and they werent dead within 2 or 3 days and are still alive today over 2 weeks later, again telling me the beneficial nematodes were not alive. So to make a long story short $200 spent and no results. Very disappointed.