It’s a Floury Baker aka Aleeta curvicosta

This is Abricta curvicosta (“floury baker”), named because of the whitish “floury” pubescent covering after emergence and the fact that it faces down the tree trunk. A goodly emergence of these around Sydney in the past month. The “razor grinder” (Henicopsaltria sp) does occur in northern Sydney around Terrey Hills, Kuringai Chase and further north in the larger timber- smaller numbers of it have emerged, but large numbers down the south coast around Berry.
David.