Photograph of one of a number of Crabs of the same species moving around on tree trunk in orchard. These seemed to be associated with the tree for the whole time that we watched them - and were, apparently, always on the same tree trunks for people undertaking the walk at the site. c4-5cm across the carapace, orangy-coloured crabs.
Looking at a couple of links, I wonder whether this is Labuanium rotundatum. (Paddy Ryan gives this an English name, Golden Tree Crab - which sounds promising although Google search takes you to loads of apple sites!). Ng and Liu (2003) Proc. Biol. Soc. Washington 116(3):601-616
provide a black and white figure of the carapace of L rotundatum - which looks pretty similar to this individual? However, the description of colour differs - with Ng and Liu stating greys and browns.