An Black Soldier Fly 黑水虻 /亮斑扁角水虻(Hermetia illucens) of about 2.5-2.8cm in length.
A Photographic Guide to Hong Kong Insects 香港昆蟲圖典 1st Edition 2014 P.389 - Hong Kong Entomological Society
Orb Spider, but I don't know which one.
From Dec to June they are all over town between the power and phone lines
Small insect about 8mm to 1cm in length. White fluffy with no apparent wings. Can hop about 20cm in one go. Normally in a group, which seem to be mating as evidenced by much smaller specimens in the group area.
Leave a white sticky residue in branches.