I saw this Crab Spider, Misumena vatia, on a Marsh Orchid at the Millennium Wetlands. The Crab Spider does not spin a web in order to feed. Instead it lies in wait on flowers and vegetation for a suitable prey species to visit and swiftly ambushes the insect. It then injects venom into the prey with the slender fangs. I thought that the victim in this case was one of the solitary bees, but I am grateful to Barry for telling me that it is, in fact, one of the bee-mimic hoverflies.