During the heavy rain we found tons of grey grubs about 1” long, a little thicker than a piece of spaghetti crawling and rolling around on our walkways and near the house foundation. Do you think they came from the lawn and crossed the walkway due to water logged grass? 2 small areas of grass were dead nearby. There were a few larger grubs found also. What are they? How do we know if they are killing the grass? How do we treat the lawn if they are killing it?
Clackamas County Oregon
Thank you for your question. Grubs would not have moves, so the likelihood is that they are crane fly larvae. But, without a photo, we can’t be positive. Here is an article about them: https://extension.oregonstate.edu/news/wet-weather-invited-crane-flies-invade-lawns I suggest you take some samples into the CC Extension office, 200 Warner Milne Road, OC, between 9 and noon, and 1 and 4 pm for ID and control suggestions. Good luck!
Thank you. This appears to be a larva of the yellow underwing moth (Noctua pronuba) which, in its larval form, is called a cutworm caterpillar. I cannot, however, see its head in the photos, and don't know how long it is. Here is an OSU article about them; perhaps you can compare to confirm: https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em9139.pdf