|Harlequin bug nymph|
Harlequin bugs (Murgantia histrionica) are a type of stink bug that will damage plants by piercing leaves and sucking the nutrients out of them. They primarily attack brassicas and other leafy crops, so it makes sense I found them on my bok choy.
I've seen adult harlequin bugs in the yard before and I know they're pests, but the nymphs look just different enough that I didn't make the connection. At least to my eye, the teenagers seem to have much rounder and plumper bodies than their adult counterparts, which seem longer and thinner with legs that stick out more.
It's too bad something so pretty is unwelcome in the garden. I don't know if I can bring myself to "control" them...maybe I'll have to plant some extra bok choy next year just for the harlequins.
And FYI: next time I encounter a UFI (unidentified flying insect) in the yard, I'm going to check the What's That Bug? website first. While it's still tricky to identify a bug if you don't know where to start (now I understand why my students always got frustrated when I told them to look up a word they didn't know how to spell in the dictionary!), this site is a great resource. If you can't figure it out on your own, you can submit a photograph and some information and ask The Bugman, who operates the site, to identify it for you.