Help please. Pest advice

[Llevrah]

Evening all. Got down to some serious weeding where I noticed a couple of problems.
I had a couple cabbage leaves, lettuce leaf and kale showing leaf miner. I have removed the offending leaves and destroyed them. What else should I be doing or looking out for please?
I also found a rather bizarre coloured beetroot leaf. I don't know if it's a dying leaf or has a problem. It's not how I'd imagine a dying beetroot leaf to look.
Can anyone help or point me in the direction of where to look?

[Llevrah]

Daft bat that I am I forgot about the chard. I have found some leaves that look like this....

[Penellype]

The beetroot leaf could just be dying back because it is one of the older leaves - I wouldn't worry about it. The chard looks like more leaf miner to me.

[Llevrah]

The beetroot leaf could just be dying back because it is one of the older leaves - I wouldn't worry about it. The chard looks like more leaf miner to me.

Oh noooooooooooo not more of it. Not sure if I was hoping leaf miner in that too or for done thing else. Don't know which is worse. Thanks for your help