I'll start with cross-striped cabbageworm
(Evergestis rimosalis) -- caterpillars and this innocuous yellow waxy smear on a broccoli leaf.
Cross-striped cabbageworm caterpillars are worse than cabbage butterfly caterpillars. Their eggs are laid in a mass and there is a mass hatching event. If you see a bunch of shot-holes suddenly appear on a leaf, it is likely to be the cross-striped cabbageworm. They feed as a group and soon skeletonize a leaf into lacey tatters.
In my garden, they have been more likely to be found on broccoli and kale than cauliflower, least likely on cabbage. They tend to appear when summer season is well under way and it gets really hot. Between the heat and devastating damage, they signal the end of cole crops for the season -- might as well harvest what's left before they eat them all.
This is an egg mass of cross-striped cabbageworm. It's flat and waxy, making it difficult to squish, but it will peel off. And if you examine it closely, you will see that they are eggs.