Green stink bug nymph, Schenley Park, 26 August 2026 (photo by Kate St. John)

9 September 2026

Two weeks ago I found this small ornate bug on a jewelweed leaf in Schenley Park. I knew I’d seen one before but it had been several (actually 15) years. I was wracking my brain to come up with a name when, “Duh! Use Google Lens.” He’s a green stink bug nymph (Chinavia hilaris).

Like other stink bugs he uses his long stylet to pierce soft plant tissues, inject his saliva containing plant-digestive enzymes, and suck the juices out of the plant. When he does this to fruits and vegetables he’s considered an agricultural pest. Fortunately he’s not invasive. In Schenley Park he chooses jewelweed but doesn’t affect the plant’s abundance.

Adult green stink bugs overwinter under leaf litter and emerge in April or May.

Green stink bug adult in Schenley Park, 29 Aug 2021 (photo by Kate St. John)

They mate in May-June and the females lay a cluster of eggs on the undersides of leaves (May-July). The eggs look like tiny barrels — very tiny compared to the leaf veins at left.

Eggs of green stink bug (photo from Wikimedia)

Not all of the eggs make it. A native parastic wasp (probably Trissolcus euschisti in this photo) lays her eggs inside the stink bug eggs. Her larvae hatch and eat the developing stink bugs. Brown marmorated stink bugs have a similar predator that traveled to North America to feed on its host.

Stinkbug egg parasitoid, Trissolcus sp. (probably Trissolcus euschisti) female, on eggs of stinkbug, Chinavia hilaris (from Wikimedia)

When the eggs hatch into nymphs they go through five instars (June-August) to become adults.

Closer look at green stink bug nymph, Schenley Park, 26 Aug 2026 (photo by Kate St. John)

Peak adult activity is in August. Then they taper (Sept-Oct) as they get ready to overwinter under the leaf litter.

Adult green stink bug on a hand (photo from Wikimedia)

Right now is the time to look for our very own stink bug. Green stink bugs won’t invade your house. Those are the brown marmorated stink bug who waits until October to plague us.

p.s. Stink bug on someone’s hand? Stink bugs don’t have teeth so they cannot bite.