garlic armageddon

I planted about 100 cloves last November and they grew away nicely and by last weekend were good strong plants until I noticed about a dozen in the middle of the patch which were yellow.I pulled one up and the foliage just came off minus bulb.The bottom of the leaves were wet and pulpy and slimy .I got a trowel and when I dug up the bulb discovered that this too was wet,slimy and mouldy with little white worms crawling all over it. :ohmy:I dug the whole lot up and about half were like this and totally useless. :mad:What is it.What is the best method of torturing the little blighters

Whatever you do, don't compost any part of the bad ones.