This observation is for the spider. The crab is logged in a separate observation. A crab was observed in the spider's web, still alive. Evidently it must have fallen into the web from a tree trunk above. It was unable to free itself and at first the spider kept its distance. Within a couple of hours, The crab was no longer moving, suggesting that the spider had successfully administered a venomous bite. The crab was subsequently trussed up in silk and carried higher up in the web by the spider.
A mutant mandarin swallowtail. Not sure what kind of mutant yet. gynandromorphic?