My own follow-up: probably a Plant Hopper in the Derbid family. Not a pest, but not beneficial, either.

Here is a link that might be useful: Bug guide

Cool! I'm familiar only with the closed wing Derbidae. I'm pretty sure, however, that they are all phytophagous (plant feeders). Planthoppers have needle like mouthparts with which they pierce the epidermis and suck plant juices.

I wouldn't worry at all about seeing a few...just thought you should know the feeding habits of your pretty little truebug.

Thanks for the reassurance. It is a pretty little thing. Any minor damage these guys could inflict pales in comparison to that caused by the Harlequin Bugs. We have been hand-picking HBs and their egg cases from Brussels Sprouts and horseradish (of all things).

Horseradish is in the same plant family as your Brussels sprouts.

Gee, you learn something new every day!