Red-shouldered Stinkbug
Thyanta custator
Observed feeding on Sacred Datura (Datura wrightii) near Castel Hot Springs, Yavapai Co., Arizona, USA. 19 April 2015. Stink bugs are NOT responsible for visible holes in the foliage - these were created by other types of plant-feeding insects.
Pentatomidae -- Stink Bug Family
Red-shouldered Stinkbug is generally distributed across much of North America. In the Sonoran Desert it is most often found on green flowering plants growing in riparian corridors. The bugs concentrate their feeding activity on flowers and fruit using their slender proboscis to pierce the tissue and suck up phloem fluids. Likely to be found on a wide variety of plant species. The extent of red on the "shoulders" is highly variable and the adults can be brown as well as green.