Large Milkweed Bug (Oncopeltus fasciatus).
This insect resembles the
Boxelder Bug but
this one is found primarily on milkweed
plants (Asclepias)
rather than on boxelder trees
(Acer
negundo). We also have a picture of
the nymphs.
The
Small Milkweed Bug is also found on
types of milkweed.
Thanks to Jennie for
identifying this plant.