I found this while gardening today, though not sure what plant it was on as I found it hurrying along the ground after being disturbed. It was about 4-5mm long and very "busy", no doubt trying to escape. At one point it let itself down by a thread, as a spider would. The first pic is of it on my arm. The black lump near the front of its back may be a piece of dirt that got stuck or it may be a natural hump on its body. The rear end was reddish orange and the front end had two large reddish protuberances just behind and each side of the head. (Could they be where the silk glands are?) The head was all black as far as I could make out, although it was difficult to get it into focus as it moved about.
Pic 4 is out of focus but may be useful for a different angle