Cactus Bugs

While shooting some pictures of the flower on this cactus, I noticed all these bugs hanging out on the back side of it. I have no idea what they are and not sure if I should kill them or let them hang out.  A quick Google search left me thinking they might be Cactus Coreid Nymphs.

Of all the links I found, none have indicated weather or not I should try to get rid of them.

• http://edis.ifas.ufl.edu/in365
• http://entnemdept.ufl.edu/creatures/beneficial/c_v_aequoris.htm
• http://www.whatsthatbug.com/2006/05/29/cactus-joint-bugs/