The insect in the photo looks like a box elder bug.  They can go through several life stages before they reach maturity. They are an insect  pest of box elder trees and a nuisance insect in and around homes.   They usually congregate to feed on boxelder trees, which are in the maple family and look somewhat similar, but the new growth has green twigs/stems.
They can move out into perennial plants, but are not typically harmful and don't usually need control. 
Here is more information  http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG%2010_2Boxelder_Bu...
  http://extension.umd.edu/hgic/boxelder-bugs-trees-and-shrubs          
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