This little guy is a Shield-backed Bug, Orsilochides guttata. The shield-backed bugs are related to the stink bugs and are true bugs, unlike the beetles they closely resemble. Like other true bugs, shield-backed bugs go through several stages of development (instars) of nymphs until they reach adulthood.
They feed on plants, including many commercial crops.
There are hundreds of species of shield-backed bugs ranging in color from rather drab to bright metallic greens and reds. Like stink bugs, when disturbed, shield-backed bugs will emit an odor to deter predators.
This little bug is perched on a goldenrod flower in late September in the Lower Wekiva Preserve State Park in Seminole County, Florida