This is probably some species of Crab Spider. They can be
identified by their long front legs, often triangular-shaped
abdomen, and sideways movement. Most species are specialized to
take prey at flowers and do not spin webs. Some have the ability
to change their color to suit the color of the flower (place it
on your S. leucophylla flowers and it might turn red).
Incidentally, it is also a crab spider that is endemic to the
pitchers of several species of nepenthes.
>I can only imagine the reception a bee would get.
Indeed! Crab spiders are well-known for their relatively potent
venom (a leading cause of death amongst Sarracenia growers) which
allows them to take large prey such a bees without the aid of a
web.
Happy pollinating,
Ch'ien