Those piles are not something you want to get rid of. Those are Earthworm mounds which is a very good thing and has noting to do with killing your Zoysia.

Earthworms aerate and enrich the soil. They do absolutely no damage to vegetation. They feed vegetation with nutrients.

So it's just a coincidence that my grass is dying specifically in the areas where this is occurring? in this particular area of my lawn most of the grass has died and it's mostly dirt now. In other areas of my lawn, where there's no such evidence, the grass is thick and healthy. Strange.

I would guess that you see the piles out in the open because they can pile up. In the dense turf they cannot build up like that. So the piles are a result of the thin grass, not a cause.

What is the shade situation in the thin area?

Can you take a picture from farther away, on a cloudy day (preferably).

Zoysia is not all it is cracked up to be. If it gets a disease, you are done for until next spring. In my neighborhood only two zoysia lawns remain. One has persistent problems. The other is a miracle lawn. I don't know how they have held it together for several years.

Was your picture taken this year or last summer?

Yeah, you're probably right, I just noticed it where the grass has thinned. The area gets plenty of sun. We've always had Zoysia and hadn't had any problems until recently. This winter we got tons of rain, so the ground was soaked for extended periods. Maybe we got a fungus in that area. Anyway, it seems to be coming back now already, as we're getting less rain and more sunny days.

DCHall,

Do you know which cultivar your neighbors had problems with? It seems that fine bladed types are the most troublesome. Wide course bladed like Palisades seemed to be much more hardy. I have several neighbors with wide bladed zoysia and they look very healthy to me. One had remarkable uniform and very nice looking zoysia front lawn. Thick and lush like a carpet. No weed or bermuda taking over. Very nice...

Mike, maybe that area got too waterlogged too long that robbed zoysa grass of oxygen. Try spreading a thin layer of compost along with cornmeal and alfalfa pellets to get soil biology back in shape to speed up recovery.

Looks like earthworms to me, but you could check for mole crickets with a soap flush. Just tossing that out.