Please search google for cabbage maggot for more information. They are white small larvae and very abundant in eating the roots of my brocculi and they lead to dead already of half of the young turnips.
When I was harvesting the radish a few were also with these but the worse is the brocculi as I noticed they were wilting (and I though it was the warm weather) and now leaves are getting pale and a bit of purple colour (since they are eating the roots!) I unroot two plants, wash well the roots and transplanted them to two containers to see what happens (brocculi usually get well with transplanting).
I read that biological control exists for controlling cabbage maggots but information is not consistent. Eventually, mint, thyme, sage, garlic, marigolds and tansy may help. I will experiment with these. I also read that parasitic wasps (Carrots, Alfalfa, Goldenrod, Horehound, Yarrow, White Clover attract these) and Diatomaceous earth (but these algae may be toxic) are described to kill and control the larvae.
Well, I feel sorry to use these words. In truth I respect Mother Nature as I am on of his sons, a tiny part of her and thus I will try to hear her messages and feel her equilibrium. I can only ask her a healing of those plants as I could have more biological organic local food grown for eating and showing my friends and companions how to grow their own food. I will add more news in soon! Love to all*