Could we be leather jack (daddy long legs as my daughters call them) pupae, this is the start of the time when they wake up and eat the grass roots - try treating the lawn with nematodes. Of course it could be a bit early, but the weather is screwing up even their body clocks!
See:
https://www.gardening-naturally.com...QyOts6Vep_oz1_EYKoLJc6ULd4Ad7WLhoCiKUQAvD_BwE
See:
https://www.gardening-naturally.com...QyOts6Vep_oz1_EYKoLJc6ULd4Ad7WLhoCiKUQAvD_BwE