Ah thank you lots! The pics I had seen of harlequins when searching “broccoli pests” looked different, but searching for harlequin bug directly got a perfect match. Gross

I just now tried your search and I saw lots of broccoli! A search for broccoli+bugs does show a few harlequins.

Harlequins are a real pest on fall brassicas here. Fairly easy to control if you get them early on before they breed. Once they build numbers You either have to roll out the big guns or give up.

What are your recommendations on control? I'm planning on doing an insecticidal soap+pyrethrin+neem oil combo? The plants still look healthy, just a few white lacy chewed spots on the leaves which I think is more likely from whiteflies. Haven't seen any catepillars yet.

If you get them before breeding and egg laying you can just hand pick them off and toss in a pot of soapy water. Takes a few days of picking to get them under control

Once egg laying has happened I find it is all but impossible to control them unless you want to use the really toxic chem pesticides - the big guns as farmerdill called them. Nothing else phases them. That's why getting them early is so important.

Dave

Liz, neither the harlequin bugs nor whitefly cause the lacy chewed parts on a plant.....both are unable to chew plants at all, but suck the photosynthates through tiny straw like mouth parts.

I'd consider caterpillars, beetles, slugs, or other chewing pests.