The spider in your photo is most likely the goldenrod crab spider, scientific name: Misumena vatia, in the family Thomisidae. This is a very common spider that ranges throughout North America. These spiders can be highly variable In color: some being bright yellow or white with no markings and some with various pink stripes or other dark markings. These spiders do not spin webs to catch their prey. Rather they are ambush predators, which rest on flowers and then capture any insect coming to visit that flower. Their enlarged front legs help to grab and hold the prey, with the spider giving it a quick bite of highly paralyzing venom that almost instantly subdues it. Thus the spider can often capture bees, butterflies and other insects that are often quite a bit larger than the spider itself. This spider is not selective, grabbing whatever insects comes along. Even though the spider eats bees that we would consider beneficial, you shouldn't consider this spider to be a "pest" since it also eats harmful insects. Bites to humans would be very rare, and probably no worse than a bee sting. I have included below some links to webpages with more information about these types of spiders.

https://en.wikipedia.org/wiki/Misumena_vatia

http://www.fcps.edu/islandcreekes/ecology/goldenrod_spider.htm

http://www.spiders.us/species/misumena-vatia/