United Kingdom 
My lawn is literally being undermined by mining bees; it's becoming unsafe to walk across it and almost impossible to mow as the ground gives way under foot; I have positively identified the culprits and whilst I know they are generally good for my garden they are ruining my lawn. What can I do?
18 Apr, 2015
Strange. Our lawns are full of mining bees too, but apart from the little mounds of soil on the surface there are few problems. There is no subsidence like you mention. Mowing and walking on the grass present no difficulties either. Are you sure there is not something else digging away under the grass? We have mole runs which do cause the grass to sink and make mowing difficult.
18 Apr, 2015