A week ago I found an adult green stink bug (Hemiptera: Pentatomidae: Chinavia hilaris) in a floodplain forest here in southeast Michigan. Two days ago I found a fifth-instar nymph in a greenhouse not far from that forest.
Most people are probably familiar with holometabolous insects like bees, butterflies, and flies that hatch as larvae, pupate, and emerge as radically different adults. Unlike those insects, these true bugs are hemimetabolous and go through several nymphal stages called instars. When the young hatch (first instar) they somewhat resemble the adults. Instead of pupating they molt several times into subsequent instars, becoming more adult-like each time.
Even though the nymph shown here was a fifth instar and only one molt away from being an adult, it still exhibited some rather distinct coloration. While adults are almost solid green, this nymph had patterns of black, orange, yellow, white, and green. Such vivid color patterns are common in stink bug nymphs (and many adults).
This was a cute little guy, even though he released defensive fluid on my fingers. Unlike many stink bugs, however, the odor didn’t seem too potent.