This is a very tiny bug that loves my yucca plants that are directly exposed to the sun. There must be hundreds of them and they are very skittish so I know that they can see me approaching. This pic is one that is clutching to the edge of a yucca leaf. Even though it looks like they have tiny wings - I don't think they can fly. Whenever they flee they just run around the underside of the yucca leaf.

We have other yuccas in the yard - in much less sunlight - that are 50 feet away that have none of these bugs at all. So is it that they only love sunlight - or that they have never made the 50 foot distance in 9 years?