davidlee, a trap crop continues to function if the pests can be destroyed but the trap itself (in this case - the cabbage plant) remains functioning.
I would suggest covering the plant (a garbage can) and fumigating it. Carbon dioxide works well.

Suggests environmental damage. What's your weather been laterly? ie: temperatures, winds; xs bright or overcast?

thank you both. I'm thinking Jean is probably right about environmental damage. Sunburn after a rain maybe? The damage is limited to the leaves that are exposed and does not seem to be spreading. Thanks again

Does broccolli need bees to produce the fruit. Will covering plant with netting for the cabbage moth be a problem if they do??

Broccoli is harvested & eaten in the flower bud stage. No bees needed.

Thank you.

what an interesting way to put it jean ...

so that cabbage head.. is just one big.. long to open flower.. go figure ....

learn something new every day ...

ken

You can eat the leaves of broccoli, too. Cook like cabbage. Taste just like broccoli and are actually more nutritious than the flower buds.