We have the fluorescent green ones here in Arizona.
These critters grow from large white/translucent looking grubs about an inch long. They look like a little "C" or crescent, as they are semi curled. Also, they have little legs, but don't seem to move around much.
I have found them in my compost piles, planting beds, living under trees where I have amended heavily, and a couple months ago, when I repotted a small first year tree that was doing poorly. I had five cuttings that I had potted earlier in the year. Four were doing very well, but this one was just not growing much at all. It wasn't growing much because these grubs eat mostly rotting vegetable matter (compost), but will also eat live roots. I found four or five of them when I repotted it. Nasty looking little buggers.
Thank you so much for the Palmolive soap spray information. I will most certainly be doing that in the Spring.