Sorry, I forgot to notice what plant these thick webs were on. The third image is a second web on the same plant showing a little more of the plant. I'm not even sure they're sawflies 🥺 Plant subsequently identified as Exocarpos cupressiformis - native cherry
Its a webbing caterpillar. I really need the name of the host plant to ID. If its Polyscias sambucifolia its the Elderberry Panax webbing caterpillar Cryptoptila australiana (Tortricidae), p 150 my book.