My take on this is that they are spiders and that the dead bits are due to other causes. If you do not see them actually sucking or chewing on the plant then do not kill any more of them, spiders are beneficial predators. If you can't post a picture here try taking samples to an Extension office, if you have one near there. A reliable independently owned and operated garden center might also have answers for you.

Hi bboy,

Thanks for you response. They are definitely not spiders. I'm very familiar with spiders of all sizes and shapes. They look like little black ticks. They have a tiny little head, a bulbous body with tiny antennae and tiny hairlike legs. They walk very slowly but faster than aphids. I had killed a batch of them a week ago and it looked like they were all gone but today I saw a few dozen all over the juniper again. When I squash them they ooze a dark red liquid. I'm totally confused.