The leaves of a holly have these white, rectangular, larvae-looking pests on the back of them. Nothing on the branches or trunk. The leaves turn black and die (illustrated by the first image showing front and back). Anybody know what it is? I thought maybe mealy bugs, but aren't mealy bugs oval shaped?
Does this pest move?
If not, look at some pictures of Cottony Cushion Scale.
If it moves, it moves very slowly. I followed your suggestion and looked up the cottony cushion scale, but that's not it. This rectangular white thing with tiny antennae just about flattens itself on to the back of the leaf. It has almost no volume, no roundness. Also it does not seem to go to any other part of the plant, as the scale appears to do.
Another bit of info may be my location, which is Raleigh, NC.
I hope someone has a clue because I realized today that not one, but 3 mature hollies are completely covered with these guys. I'll try our extension center, but sadly there are not enough master gardeners to volunteer and many times, when I've gone for help, there was none to be had.
It does sound like a pest, not a beneficial insect. Why not try something mild like insecticidal soap?
